Aerosol generating system having a compressible aerosol generating article

Abstract

The aerosol-generating system comprises an aerosol-generating article (10) including an aerosol-generating substrate rod (12) and a downstream section (22) located downstream of the aerosol-generating substrate rod (12); an aerosol-generating device (100) comprising: a body defining a heating chamber (108), (208), (308) for removably receiving at least a portion of the aerosol-generating substrate rod (12) when the aerosol-generating article (10) is inserted into the aerosol-generating device (100); and a heater assembly disposed along at least a portion of the heating chamber (108), (208), (308) for heating the aerosol-generating substrate rod (12). The cross section of the heating chambers 108, 208, 308 of the aerosol-generating device 100 is configured such that, upon insertion of the aerosol-generating substrate rod 12 into the heating chambers 108, 208, 308, the aerosol-generating substrate rod 12 is compressed to a final density that is at least 1.5 times its initial density, the initial density of the aerosol-generating substrate rod 12 being less than 250 milligrams per cubic centimeter.

Description

[Technical Field]

[0001] The present invention relates to an aerosol generating system comprising an aerosol generating device and a compressible aerosol-generating article. [Background technology]

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

[0003] Numerous prior art documents disclose aerosol generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol generating devices in which aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generating device to an aerosol-generating substrate of the heated aerosol-generating article. For example, an electrically heated aerosol generating device has been proposed that includes an internal heater blade adapted to be inserted into the aerosol-generating substrate. Alternatively, WO 2015 / 176898 proposes an inductively heated aerosol-generating article that includes an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate. A further alternative is described in WO 2020 / 115151, which discloses an aerosol-generating article used in combination with an external heating system that includes one or more heating elements disposed around the outer surface of the aerosol-generating article.

[0004] Typically, aerosol-generating articles are manufactured with a substantially round cross-section so that the aerosol-generating substrate is cylindrical. The device cavity of a corresponding aerosol-generating device for heating the aerosol-generating article often has a cylindrical shape and size configured to substantially match the shape and size of the aerosol-generating substrate, thereby allowing the aerosol-generating substrate to be easily received and retained within the device cavity during heating. Summary of the Invention [Problem to be solved by the invention]

[0005] However, an improved aerosol generating device has been proposed, which has a device cavity with a rectangular cross section including opposing planar walls. In this device, a heater element is provided on at least one surface. This arrangement potentially increases the surface area available for heating the aerosol-generating substrate, significantly improving the efficiency of heating the aerosol-generating substrate. It also provides a more compact aerosol generating system that is easier to manufacture. However, consumers may have difficulty using such an aerosol generating device with a conventional cylindrical aerosol-generating article, as it can be difficult to compress or deform the cylindrical aerosol-generating substrate sufficiently to insert it into the rectangular device cavity. This is particularly true when the planar walls of the device cavity are relatively close together and the distance between the planar walls is significantly less than the diameter.

[0006] Therefore, there is a need for an aerosol generating system that includes an aerosol generating device and an aerosol generating article that is more compatible with the shape of the aerosol generating article when the shape of the aerosol generating article differs from the device cavity of the aerosol generating device. [Means for solving the problem]

[0007] According to a first aspect of the present disclosure, there is provided an aerosol generation system. The aerosol generation system may comprise an aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article extending from a mouth end to a distal end. The aerosol-generating article may comprise a rod of an aerosol-generating substrate. The aerosol-generating article may include a downstream section located downstream of the rod of aerosol-generating substrate, the downstream section extending from the downstream end of the rod of aerosol-generating substrate to the mouth end of the aerosol-generating article. The aerosol generation system may further comprise an aerosol-generating device. The aerosol-generating device may comprise a body defining a heating chamber for removably receiving at least a portion of the rod of aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device. The aerosol-generating device may comprise a heater assembly disposed along at least a portion of the heating chamber for heating the rod of aerosol-generating substrate when the aerosol-generating article is received in the aerosol-generating device. The rod of aerosol-generating substrate may have an initial density before the aerosol-generating article is inserted into the aerosol-generating device. The cross-section of the heating chamber of the aerosol-generating device may be configured such that, when the rod of aerosol-generating substrate is inserted into the heating chamber, the rod of aerosol-generating substrate is compressed to a final density. The final density may be at least 1.1 times the initial density.

[0008] According to the present invention, there is provided an aerosol generation system comprising: an aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article including a rod of aerosol-generating substrate extending from a mouth end to a distal end and including a downstream section located downstream of the rod of aerosol-generating substrate, the downstream section extending from the downstream end of the rod of aerosol-generating substrate to the mouth end of the aerosol-generating article; and an aerosol-generating device comprising: a body defining a heating chamber for removably receiving at least a portion of the rod of aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device; and a heater assembly disposed along at least a portion of the heating chamber for heating the rod of aerosol-generating substrate when the aerosol-generating article is received in the aerosol-generating device. According to the present invention, the rod of aerosol-generating substrate has an initial density prior to insertion of the aerosol-generating article into the aerosol-generating device, and the cross-section of the heating chamber of the aerosol-generating device is configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final density that is at least 1.1 times the initial density.

[0009] According to a second aspect of the present disclosure, there is provided an aerosol generation system. The aerosol generation system may comprise an aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article extending from a mouth end to a distal end. The aerosol-generating article may comprise a rod of aerosol-generating substrate. The aerosol-generating article may include a downstream section located downstream of the rod of aerosol-generating substrate, the downstream section extending from the downstream end of the rod of aerosol-generating substrate to the mouth end of the aerosol-generating article. The aerosol generation system may further comprise an aerosol-generating device. The aerosol-generating device may comprise a body defining a heating chamber for removably receiving at least a portion of the rod of aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device. The aerosol-generating device may comprise a heater assembly disposed along at least a portion of the heating chamber for heating the rod of aerosol-generating substrate when the aerosol-generating article is received in the aerosol-generating device. The rod of aerosol-generating substrate may have an initial cross-sectional area prior to insertion of the aerosol-generating article into the aerosol-generating device. The cross-sectional area of ​​the heating chamber of the aerosol-generating device may be configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final cross-sectional area. The initial cross-sectional area may be at least 1.1 times the final cross-sectional area.

[0010] According to the present invention, there is provided an aerosol generation system comprising: an aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article including a rod of aerosol-generating substrate extending from a mouth end to a distal end and including a downstream section located downstream of the rod of aerosol-generating substrate, the downstream section extending from the downstream end of the rod of aerosol-generating substrate to the mouth end of the aerosol-generating article; and an aerosol-generating device comprising: a body defining a heating chamber for removably receiving at least a portion of the rod of aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device; and a heater assembly for heating the rod of aerosol-generating substrate when the rod of aerosol-generating substrate is received in the heating chamber. According to the present invention, the rod of aerosol-generating substrate has an initial cross-sectional area prior to insertion of the aerosol-generating article into the aerosol-generating device, and the cross-sectional area of ​​the heating chamber of the aerosol-generating device is configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final cross-sectional area, the initial cross-sectional area being at least 1.1 times the final cross-sectional area.

[0011] According to a third aspect of the present disclosure, there is provided an aerosol generation system. The aerosol generation system may comprise an aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article extending from a mouth end to a distal end. The aerosol-generating article may comprise a rod of aerosol-generating substrate. The aerosol-generating article may include a downstream section located downstream of the rod of aerosol-generating substrate, the downstream section extending from the downstream end of the rod of aerosol-generating substrate to the mouth end of the aerosol-generating article. The aerosol generation system may further comprise an aerosol-generating device. The aerosol-generating device may comprise a body defining a heating chamber for removably receiving at least a portion of the rod of aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device. The aerosol-generating device may comprise a heater assembly disposed along at least a portion of the heating chamber for heating the rod of aerosol-generating substrate when the aerosol-generating article is received in the aerosol-generating device. The rod of aerosol-generating substrate may have an initial maximum diameter prior to insertion of the aerosol-generating article into the aerosol-generating device. The cross-section of the heating chamber of the aerosol-generating device may be configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final maximum diameter. The final maximum diameter after compression may be at least 1.1 times the initial maximum diameter.

[0012] According to the present invention, there is provided an aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article including a rod of aerosol-generating substrate extending from an oral end to a distal end and including a downstream section located downstream of the rod of aerosol-generating substrate, the downstream section extending from the downstream end of the rod of aerosol-generating substrate to the oral end of the aerosol-generating article; and an aerosol-generating device including a body defining a heating chamber for removably receiving at least a portion of the rod of aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device; and a heater assembly for heating the rod of aerosol-generating substrate when the rod of aerosol-generating substrate is received within the heating chamber, wherein the rod of aerosol-generating substrate has an initial maximum diameter prior to insertion of an aerosol-generating article into the aerosol-generating device, and the cross-section of the heating chamber of the aerosol-generating device is configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed, and the final maximum diameter after compression is at least 1.1 times the initial maximum diameter.

[0013] As used herein, the term "aerosol-generating article" refers to an article that heats an aerosol-generating substrate to generate an inhalable aerosol for delivery to a consumer. As used herein, the term "aerosol-generating substrate" refers to a substrate that has the ability to release volatile compounds upon heating to generate an aerosol.

[0014] As used herein, the term "aerosol-generating device" refers to a device that includes a heater element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0015] As used herein in connection with the present invention, the term "rod" is used to denote a generally elongated element, preferably a cylindrical element of substantially circular, oval or elliptical cross section.

[0016] As used herein, the term "longitudinal" refers to a direction corresponding to a major longitudinal axis of the aerosol-generating article extending between the upstream and downstream ends of the aerosol-generating article. As used herein, the terms "upstream" and "downstream" describe the relative positions of elements (or portions of elements) of the aerosol-generating article with respect to the direction in which aerosol is transported through the aerosol-generating article during use.

[0017] During use, air is drawn "longitudinally" through the aerosol-generating article. The term "transverse" refers to a direction perpendicular to the longitudinal axis. Any reference to a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refers to a transverse cross section, unless otherwise specified.

[0018] The term "length" refers to the dimension of a component of an aerosol-generating article in the longitudinal direction. For example, it may be used to refer to the dimension of a rod or downstream section in the longitudinal direction.

[0019] The term "density" as used herein in relation 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 segment of the aerosol-generating substrate (excluding the wrapper). The initial density of the aerosol-generating substrate refers to the density of the aerosol-generating substrate before insertion into the aerosol-generating device. The final density of the aerosol-generating substrate refers to the density of the aerosol-generating substrate after it has been placed in the aerosol-generating device.

[0020] In all aspects of the invention, the aerosol-generating system comprises an aerosol-generating article adapted to compress the aerosol-generating substrate. The heating chamber is configured with a specific size and shape relative to the aerosol-generating substrate so that when a consumer inserts the aerosol-generating article into the aerosol-generating device, the aerosol-generating substrate of the aerosol-generating article is compressed prior to heating. This compression of the aerosol-generating substrate causes a change in the shape and configuration of the aerosol-generating substrate.

[0021] The aerosol-generating system of the present invention therefore provides a novel combination of an aerosol-generating device and an aerosol-generating article in which the initial shape of the aerosol-generating substrate is adapted when the aerosol-generating article is inserted into the aerosol-generating device in order to improve the heating efficiency of the aerosol-generating substrate during use. In particular, compressing or flattening the aerosol-generating substrate when inserted into the heating chamber of the aerosol-generating device reduces at least one dimension of the aerosol-generating substrate. As a result, heat can be transferred more efficiently through the aerosol-generating substrate, maximizing the release of the active ingredient from the aerosol-generating substrate.

[0022] In the aerosol-generating system of the present invention, the compressible adaptation of the aerosol-generating article allows the aerosol-generating article to be inserted into a "flat" heater having a heating chamber with a flat heating surface, as described below, despite the different geometries of the aerosol-generating article and the heating chamber. Thus, the advantages of using a "flat" heater in terms of more efficient heating can still be obtained even with cylindrical articles.

[0023] Advantageously, the remaining portion of the aerosol-generating article that is not inserted into the aerosol-generating device does not need to be compressed, so that the properties and functionality of the downstream section of the aerosol-generating article are little or not affected at all.

[0024] In the aerosol-generating system according to the first aspect of the present invention, the aerosol-generating article and the heating chamber of the aerosol-generating device are adapted so that, when inserted into the aerosol-generating device, the aerosol-generating substrate is compressed and the density of the aerosol-generating substrate increases by at least 1.1 times from the initial density to the final density. Thus, the ratio of the final density to the initial density, obtained by dividing the final density by the initial density, is at least 1.1. Preferably, the initial density of the aerosol-generating substrate is relatively low so that it can be compressed sufficiently for insertion into the heating chamber of the aerosol-generating device.

[0025] The initial density of the aerosol-generating substrate is preferably less than 300 milligrams per cubic centimeter, more preferably less than 275 milligrams per cubic centimeter, more preferably less than 250 milligrams per cubic centimeter, more preferably less than 225 milligrams per cubic centimeter, more preferably less than 200 milligrams per cubic centimeter, more preferably less than 175 milligrams per cubic centimeter, more preferably less than 150 milligrams per cubic centimeter, and more preferably less than 125 milligrams per cubic centimeter.

[0026] The initial density is preferably at least 75 milligrams per cubic centimeter, more preferably at least 80 milligrams per cubic centimeter, more preferably at least 85 milligrams per cubic centimeter, more preferably at least 90 milligrams per cubic centimeter, more preferably at least 95 milligrams per cubic centimeter, more preferably at least 100 milligrams per cubic centimeter, more preferably at least 105 milligrams per cubic centimeter, and more preferably at least 110 milligrams per cubic centimeter.

[0027] For example, the initial density may be 75 milligrams / cubic centimeter to 300 milligrams / cubic centimeter, or 80 milligrams / cubic centimeter to 275 milligrams / cubic centimeter, or 85 milligrams / cubic centimeter to 250 milligrams / cubic centimeter, or 90 milligrams / cubic centimeter to 225 milligrams / cubic centimeter, or 95 milligrams / cubic centimeter to 200 milligrams / cubic centimeter, or 100 milligrams / cubic centimeter to 175 milligrams / cubic centimeter, or 105 milligrams / cubic centimeter to 150 milligrams / cubic centimeter, or 110 milligrams / cubic centimeter to 125 milligrams / cubic centimeter.

[0028] The final density of the aerosol-generating substrate after insertion into the heated chamber of the aerosol-generating device depends on the initial density and the degree to which the aerosol-generating substrate is compressed when inserted into the aerosol-generating device. According to the present invention, the final density is at least 1.1 times the initial density. Preferably, the final density is at least 1.25 times the initial density, more preferably at least 1.5 times the initial density, more preferably at least 1.75 times the initial density, and even more preferably at least 2 times the initial density. The final density may be up to four times the initial density, or up to three times the initial density.

[0029] For example, the final density may be 1.1 to 4 times the initial density, or 1.25 to 4 times the initial density, or 1.5 to 4 times the initial density, or 1.75 to 4 times the initial density, or 2 to 4 times the initial density, or 1.1 to 3 times the initial density, or 1.25 to 3 times the initial density, or 1.5 to 3 times the initial density, or 1.75 to 3 times the initial density, or 2 to 3 times the initial density.

[0030] Preferably, the final density is at least 150 milligrams per cubic centimeter, more preferably at least 175 milligrams per cubic centimeter, more preferably at least 200 milligrams per cubic centimeter, more preferably at least 225 milligrams per cubic centimeter, more preferably at least 250 milligrams per cubic centimeter, more preferably at least 275 milligrams per cubic centimeter, and more preferably at least 300 milligrams per cubic centimeter.

[0031] Preferably, the final density of the aerosol-generating substrate is less than 500 milligrams per cubic centimeter, more preferably less than 475 milligrams per cubic centimeter, more preferably less than 450 milligrams per cubic centimeter, more preferably less than 425 milligrams per cubic centimeter, more preferably less than 400 milligrams per cubic centimeter, more preferably less than 375 milligrams per cubic centimeter, more preferably less than 350 milligrams per cubic centimeter.

[0032] For example, the final density may be 150 milligrams / cubic centimeter to 500 milligrams / cubic centimeter, or 175 milligrams / cubic centimeter to 475 milligrams / cubic centimeter, 200 milligrams / cubic centimeter to 450 milligrams / cubic centimeter, or 225 milligrams / cubic centimeter to 425 milligrams / cubic centimeter, or 250 milligrams / cubic centimeter to 400 milligrams / cubic centimeter, or 275 milligrams / cubic centimeter to 375 milligrams / cubic centimeter, or 300 milligrams / cubic centimeter to 350 milligrams / cubic centimeter.

[0033] Alternatively or additionally, the aerosol-generating article and the heating chamber of the aerosol-generating device are adapted to cause the aerosol-generating substrate to deform and change shape upon insertion into the aerosol-generating device, whereby the cross-sectional area of ​​the aerosol-generating substrate is reduced, with the initial cross-sectional area being at least 1.1 times the final cross-sectional area.

[0034] The cross-sectional area of ​​the rod of aerosol-generating substrate refers to the area of ​​a cross section taken through the rod of aerosol-generating substrate in a direction transverse or perpendicular to the longitudinal axis of the rod of aerosol-generating substrate, extending along the length of the elongate rod as defined above. Where the cross-sectional area varies along the length of the rod of aerosol-generating substrate, the average cross-sectional area should be considered.

[0035] In many preferred embodiments, the reduction in cross-sectional area that accompanies insertion of the aerosol-generating article into the heating chamber of the aerosol-generating device occurs due to deformation of the rod of the aerosol-generating substrate from a substantially circular cross-section to a more elliptical or rectangular cross-section. Thus, insertion of the aerosol-generating article into the heating chamber typically results in a general flattening of the rod of the aerosol-generating substrate in one direction. This flattening improves the transfer of heat through the rod of the aerosol-generating substrate during heating, thereby increasing the efficiency of aerosol generation from the aerosol-generating substrate.

[0036] The initial cross-sectional area of ​​the rod of the aerosol-generating substrate is preferably at least 28 square millimeters, more preferably at least 30 square millimeters, more preferably at least 32 square millimeters, more preferably at least 34 square millimeters, and more preferably at least 36 square millimeters.

[0037] The initial cross-sectional area of ​​the rod of the aerosol-generating substrate is preferably less than 50 square millimeters, more preferably less than 48 square millimeters, more preferably less than 46 square millimeters, more preferably less than 44 square millimeters, and more preferably less than 42 square millimeters.

[0038] For example, the initial transverse cross-sectional area of ​​the rod of the aerosol-generating substrate may be 28 to 50 square millimeters, or 30 to 48 square millimeters, or 32 to 46 square millimeters, or 34 to 44 square millimeters, or 36 to 42 square millimeters.

[0039] The final cross-sectional area of ​​the aerosol-generating substrate rod after insertion into the heated chamber of the aerosol-generating device depends on the initial cross-sectional area and the degree to which the aerosol-generating substrate rod is compressed or deformed during insertion into the aerosol-generating device. According to the present invention, the initial cross-sectional area is at least 1.1 times the final cross-sectional area. Preferably, the initial cross-sectional area is at least 1.25 times the final cross-sectional area, more preferably at least 1.5 times the final cross-sectional area, more preferably at least 1.75 times the final cross-sectional area, and even more preferably at least two times the final cross-sectional area. The initial cross-sectional area may be up to four times the final cross-sectional area, or up to three times the final cross-sectional area.

[0040] For example, the initial cross-sectional area may be 1.1 to 4 times the final cross-sectional area, or 1.25 to 4 times the final cross-sectional area, or 1.5 to 4 times the final cross-sectional area, or 1.75 to 4 times the final cross-sectional area, or 2 to 4 times the final cross-sectional area, or 1.1 to 3 times the final cross-sectional area, or 1.25 to 3 times the final cross-sectional area, or 1.5 to 3 times the final cross-sectional area, or 1.75 to 3 times the final cross-sectional area, or 2 to 3 times the final cross-sectional area.

[0041] Preferably, the final transverse cross-sectional area is less than 30 square millimeters, more preferably less than 28 square millimeters, more preferably less than 26 square millimeters, more preferably less than 24 square millimeters, more preferably less than 22 square millimeters.

[0042] Preferably, the final transverse cross-sectional area is at least 10 square millimeters, more preferably at least 12 square millimeters, more preferably at least 14 square millimeters, more preferably at least 16 square millimeters, more preferably at least 18 square millimeters.

[0043] For example, the final transverse cross-sectional area may be between 10 square millimeters and 30 square millimeters, or between 12 square millimeters and 28 square millimeters, or between 14 square millimeters and 26 square millimeters, or between 16 square millimeters and 24 square millimeters, or between 18 square millimeters and 22 square millimeters.

[0044] Alternatively or additionally, the aerosol-generating article and the heating chamber of the aerosol-generating device are adapted so that upon insertion into the aerosol-generating device, the aerosol-generating substrate is compressed, increasing the maximum diameter of the rod of the aerosol-generating substrate, and the final maximum diameter being at least 1.1 times the initial maximum diameter.

[0045] The maximum diameter of the aerosol-generating substrate rod refers to the largest outer dimension of the aerosol-generating substrate rod in a plane transverse or perpendicular to the longitudinal axis of the aerosol-generating substrate rod. In other words, the maximum diameter corresponds to the largest outer dimension of the cross-section of the aerosol-generating substrate rod. If the cross-section varies along the length of the aerosol-generating substrate rod, the average maximum diameter should be considered. If the aerosol-generating substrate rod has a substantially circular cross-section, the maximum diameter corresponds to the overall diameter of the circle.

[0046] In many preferred embodiments, compression of the aerosol-generating substrate rod accompanying insertion of the aerosol-generating article into the heating chamber of the aerosol-generating device results in deformation of the aerosol-generating substrate rod from a substantially circular cross-section toward a more elliptical or rectangular cross-section. Thus, insertion of the aerosol-generating article into the heating chamber typically results in a general flattening of the aerosol-generating substrate rod in one direction and a corresponding increase in its maximum diameter. This flattening improves heat transfer through the aerosol-generating substrate rod during heating, thereby increasing the efficiency of aerosol generation from the aerosol-generating substrate.

[0047] Preferably, the initial maximum diameter of the rod of the aerosol-generating substrate, before the aerosol-generating article is inserted into the aerosol-generating device, is at least 6 millimeters, more preferably at least 6.25 millimeters, more preferably at least 6.5 millimeters, more preferably at least 6.75 millimeters, more preferably at least 7 millimeters.

[0048] Preferably, the initial maximum diameter of the rod of the aerosol-generating substrate, before the aerosol-generating article is inserted into the aerosol-generating device, is less than 8.5 millimeters, more preferably less than 8.25 millimeters, more preferably less than 8 millimeters, more preferably less than 7.75 millimeters, more preferably less than 7.5 millimeters.

[0049] For example, the initial maximum diameter may be 6 mm to 8.5 mm, or 6.25 mm to 8.25 mm, or 6.5 mm to 8 mm, or 6.75 mm to 7.75 mm, or 7 mm to 7.5 mm. The initial maximum diameter may be approximately 7.1 mm.

[0050] The final maximum diameter of the aerosol-generating substrate rod after insertion into the heated chamber of the aerosol-generating device depends on the initial maximum diameter and the degree to which the aerosol-generating substrate rod is compressed during insertion into the aerosol-generating device. According to the present invention, the final maximum diameter is at least 1.1 times the initial maximum diameter. Preferably, the final maximum diameter is at least 1.15 times the initial maximum diameter, more preferably at least 1.2 times the initial maximum diameter, and more preferably at least 1.25 times the initial maximum diameter. The final maximum diameter may be up to three times the initial maximum diameter, or up to two times the initial maximum diameter.

[0051] For example, the final maximum diameter may be 1.1 to 3 times the initial maximum diameter, or 1.15 to 3 times the initial maximum diameter, or 1.2 to 3 times the initial maximum diameter, or 1.25 to 3 times the initial maximum diameter, or 1.1 to 2 times the initial maximum diameter, or 1.15 to 2 times the initial maximum diameter, or 1.2 to 2 times the initial maximum diameter, or 1.25 to 2 times the initial maximum diameter.

[0052] Preferably, the final maximum diameter of the rod of the aerosol-generating substrate after insertion of the aerosol-generating article into the aerosol-generating device is at least 8 millimeters, more preferably at least 8.25 millimeters, more preferably at least 8.5 millimeters, more preferably at least 8.75 millimeters, more preferably at least 9 millimeters.

[0053] Preferably, the final maximum diameter of the rod of the aerosol-generating substrate after insertion of the aerosol-generating article into the aerosol-generating device is less than 10.5 millimeters, more preferably less than 10.25 millimeters, more preferably less than 10 millimeters, more preferably less than 9.75 millimeters, more preferably less than 9.5 millimeters.

[0054] For example, the final maximum diameter may be 8 mm to 10.5 mm, or 8.25 mm to 10.25 mm, or 8.5 mm to 10 mm, or 8.75 mm to 9.75 mm, or 9 mm to 9.5 mm. The final maximum diameter may be approximately 9.2 mm.

[0055] In all aspects of the present invention, insertion of the aerosol-generating article into the aerosol-generating device preferably results in a generally flattened rod of aerosol-generating substrate, as described above. Preferably, the rod of aerosol-generating substrate has a substantially circular cross-section before insertion of the aerosol-generating article into the aerosol-generating device. Preferably, after insertion of the aerosol-generating article into the aerosol-generating device, the rod of aerosol-generating substrate has a substantially rectangular cross-section. Alternatively, after insertion of the aerosol-generating article into the aerosol-generating device, the rod of aerosol-generating substrate may have a substantially elliptical cross-section.

[0056] When the rod of aerosol-generating substrate has a substantially rectangular cross-section after insertion of the aerosol-generating article into the aerosol-generating device, the width of the rectangle is preferably at least twice the height of the rectangle, more preferably at least three times the height, and even more preferably at least four times the height. The width and height of the rectangle are measured perpendicular to each other, with the width of the rectangle corresponding to the longer of the two dimensions. The width therefore corresponds to the maximum diameter of the cross-section of the rod of aerosol-generating substrate, and preferably has a value within the range defined above for the final maximum diameter of the rod of aerosol-generating substrate. The height of the rectangle is preferably between 1 millimeter and 4 millimeters, or between 1.5 millimeters and 3.5 millimeters, or between 2 millimeters and 3 millimeters.

[0057] As noted above, insertion of the aerosol-generating article into the aerosol-generating device may result in some compression and deformation of the aerosol-generating substrate. This compression may affect the resistance to withdrawal (RTD) of the rod of the aerosol-generating substrate, and the aerosol-generating article should be adapted so that the resistance to withdrawal of the aerosol-generating article after insertion into the aerosol-generating device is within an acceptable range, as defined below.

[0058] Unless otherwise specified, the resistance to draw (RTD) of a component or aerosol-generating 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 "draw resistance" of a component or article can also refer to "resistance to draw." These terms generally refer to measurements in accordance with ISO 6565-2015 being performed successfully under test conditions of 22 degrees Celsius, 101 kPa (approximately 760 Torr), and 60% relative humidity, with a volumetric flow rate of 17.5 milliliters per second at the output or downstream end of the measured component. Smoking conditions and smoking machine specifications are provided in ISO Standard 3308 (ISO 3308:2000). Conditioning and testing atmospheres are provided in ISO Standard 3402 (ISO 3402:1999).

[0059] After insertion of the aerosol-generating article into the aerosol-generating device, the RTD of the rod of the aerosol-generating substrate is preferably 10 millimeters HO or less, more preferably 9 millimeters HO or less, and even more preferably 8 millimeters HO or less.

[0060] After insertion of the aerosol-generating article into the aerosol-generating device, the RTD of the rod of the aerosol-generating substrate is preferably at least 4 millimeters HO, more preferably at least 5 millimeters HO, and even more preferably at least 6 millimeters HO.

[0061] For example, the RTD of the rod of aerosol-generating substrate after insertion of the aerosol-generating article into the aerosol-generating device may be between 4 millimeters HO and 10 millimeters HO, or between 5 millimeters HO and 10 millimeters HO, or between 6 millimeters HO and about 10 millimeters HO, or between 4 millimeters HO and 9 millimeters HO, or between 5 millimeters HO and 9 millimeters HO, or between 6 millimeters HO and 9 millimeters HO, or between 4 millimeters HO and 8 millimeters HO, or between 5 millimeters HO and 8 millimeters HO, or between 6 millimeters HO and 8 millimeters HO.

[0062] Preferably, the aerosol-generating substrate rod has a length of at least 8 mm, more preferably at least 9 mm, and even more preferably at least 10 mm. Preferably, the aerosol-generating substrate rod has a length of less than 16 mm, more preferably less than 15 mm, and even more preferably less than 14 mm. For example, the aerosol-generating substrate rod may have a length of 8 mm to 16 mm, or 9 mm to 15 mm, or 10 mm to 14 mm. In one particularly preferred embodiment, the aerosol-generating substrate rod has a length of about 12 mm.

[0063] The ratio of the length of the aerosol-generating substrate rod to the total length of the aerosol-generating article is preferably at least 0.10, more preferably at least 0.15, more preferably at least 0.20, more preferably at least 0.25. The ratio of the length of the aerosol-generating substrate rod to the total length of the aerosol-generating article is preferably less than 0.50, more preferably less than 0.45, more preferably less than 0.40, more preferably less than 0.35. For example, the ratio of the aerosol-generating substrate rod to the total length of the aerosol-generating article may be 0.1 to 0.5, or 0.15 to 0.45, or 0.2 to 0.4, or 0.25 to 0.35.

[0064] Prior to insertion of the aerosol-generating article into the aerosol-generating device, the rod of the aerosol-generating substrate preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0065] Prior to insertion of the aerosol-generating article into the aerosol-generating device, the rod of aerosol-generating substrate preferably has an outer diameter of at least 5 millimeters, more preferably at least 6 millimeters, and more preferably at least 7 millimeters. Prior to insertion of the aerosol-generating article into the aerosol-generating device, the rod of aerosol-generating substrate preferably has an outer diameter of less than 12 millimeters, more preferably less than 10 millimeters, and more preferably less than 8 millimeters. For example, the outer diameter may be between 5 millimeters and 12 millimeters, or between 6 millimeters and 10 millimeters, or between 7 millimeters and 8 millimeters. In a particularly preferred embodiment, the rod of aerosol-generating substrate has an outer diameter of approximately 7.1 millimeters.

[0066] Preferably, the rod of aerosol-generating substrate has a substantially uniform cross-section along the length of the rod, and it is particularly preferred that the rod of aerosol-generating substrate has a substantially circular cross-section prior to insertion of the aerosol-generating article into the aerosol-generating device.

[0067] The aerosol-generating substrate may be a solid aerosol-generating substrate. Suitable types of materials for use in the aerosol-generating substrate are described below and include, for example, tobacco cut filler, homogenized tobacco materials such as cast leaf, aerosol-generating films, and gel compositions.

[0068] The aerosol-generating substrate preferably includes an aerosol former. The aerosol former can be any suitable known compound or mixture of compounds that promotes the formation of a dense, stable aerosol during use. The aerosol former can promote the aerosol to be substantially resistant to thermal decomposition at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol formers include, for example, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, propylene glycol, glycerin, etc.), esters of polyhydric alcohols (e.g., glycerol mono-, di-, or triacetate, etc.), aliphatic esters of mono-, di-, or polycarboxylic acids (e.g., dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.), and combinations thereof.

[0069] The aerosol former preferably comprises one or more of glycerin and propylene glycol. The aerosol former may consist of glycerin, or propylene glycol, or a combination of glycerin and propylene glycol.

[0070] In certain embodiments, the aerosol-generating substrate preferably comprises at least 5 weight percent aerosol formers on a dry weight basis, more preferably at least 10 weight percent on a dry weight basis, and more preferably at least 15 weight percent on a dry weight basis. In such embodiments, the aerosol-generating substrate preferably comprises no more than 30 weight percent aerosol formers on a dry weight basis of the aerosol-generating substrate, more preferably no more than 25 weight percent on a dry weight basis, and more preferably no more than 20 weight percent on a dry weight basis. For example, the aerosol-generating substrate may have an aerosol-former content of 5 to 30 weight percent, or 10 to 25 weight percent, or about 15 to about 20 weight percent on a dry weight basis. Thus, in such embodiments, the aerosol-former content is relatively low.

[0071] In other embodiments, the aerosol-generating substrate preferably comprises at least 40 percent by weight of aerosol formers based on the dry weight of the aerosol-generating substrate, more preferably at least 45 percent by weight on a dry weight basis, and more preferably at least 50 percent by weight on a dry weight basis. In these embodiments, the aerosol-generating substrate preferably comprises no more than 80 percent by weight of aerosol formers based on the dry weight of the aerosol-generating substrate, more preferably no more than 75 percent by weight on a dry weight basis, and more preferably no more than 70 percent by weight on a dry weight basis. For example, the aerosol-generating substrate may have an aerosol-former content of 40 percent to 80 percent by weight, or 45 percent to 75 percent by weight, or about 50 percent to about 70 percent by weight on a dry weight basis. In these embodiments, the aerosol-former content is relatively high.

[0072] In some preferred embodiments, the aerosol-generating substrate comprises tobacco material. For example, the aerosol-generating substrate may comprise cut 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 shredded sheets of homogenized tobacco material. Suitable homogenized tobacco materials for use in the present invention are described below.

[0073] In the context of this specification, the term "cut filler" is used to describe a blend of finely chopped plant material, such as tobacco plant material, specifically including one or more of leaf blades, processed stems and veins, and homogenized plant material.

[0074] Cut filler may also include other cuts, filler tobacco, or casings.

[0075] Preferably, the cut filler comprises at least 25 percent of the plant leaf blades, more preferably at least 50 percent of the plant leaf blades, even more preferably at least 75 percent of the plant leaf blades, and most preferably at least 90 percent of the plant leaf blades. Preferably, the plant material is one of tobacco, mint, tea, and cloves. Most preferably, the plant material is tobacco. However, the present invention is equally applicable to other plant materials capable of releasing a substance upon application of heat and subsequently forming an aerosol.

[0076] The cut filler suitable for use in the present invention may generally be similar to the cut filler used in conventional smoking articles. The cut width of the cut filler is preferably 0.3 mm to 2.0 mm, or 0.5 mm to 1.2 mm, or 0.6 mm to 0.9 mm.

[0077] Preferably, the strands have a length of from about 10 millimeters to about 40 millimeters, and the strands are then aligned to form a rod of the aerosol-generating substrate.

[0078] In a preferred embodiment, the weight of the cut filler is between 25 milligrams and 150 milligrams, preferably between 30 milligrams and 125 milligrams, and more preferably between 40 milligrams and 100 milligrams. This amount of cut filler typically provides sufficient material for aerosol formation during the initial puff.

[0079] Preferably, the cut filler is immersed in the aerosol former. The immersion of the cut filler can be achieved by spraying or other suitable application methods. The aerosol former can be added to the blend during the preparation of the cut filler. For example, the aerosol former can be applied to the blend in a direct conditioning casing cylinder (DCCC). Conventional machines can be used to apply the aerosol former to the cut filler. Suitable aerosol formers are presented above.

[0080] The aerosol former in the cut filler preferably comprises one or more of glycerol and propylene glycol. The aerosol former may comprise glycerol, or propylene glycol, or a combination of glycerin and propylene glycol.

[0081] In another preferred embodiment, the aerosol-generating substrate comprises homogenized plant material, preferably homogenized tobacco material.

[0082] As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomeration of plant particles. For example, a sheet or web of homogenized tobacco material for an aerosol-generating substrate of the present invention may be formed by agglomerating particles of tobacco material obtained by grinding, crushing, or comminuting plant material and, optionally, one or more of tobacco lamina and tobacco stems. Homogenized plant material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0083] The homogenized plant material can be provided in any suitable form.

[0084] In some embodiments, the homogenized plant material may be in the form of one or more sheets. As used herein with respect to the present invention, the term "sheet" describes a layered element having a width and length that is substantially greater than its thickness.

[0085] The homogenized plant material may be in the form of a plurality of pellets or granules.

[0086] The homogenized plant material may be in the form of multiple strands, pieces, or fragments. As used herein, the term "strand" describes an elongated element of material having a length substantially greater than its width and thickness. The term "strand" should be considered to encompass pieces, fragments, and any other homogenized plant material having a similar morphology. Strands of homogenized plant material may be formed from a sheet of homogenized plant material, for example, by cutting or chopping, or by other methods, such as extrusion.

[0087] The aerosol former content of the homogenized tobacco material is preferably within the range defined above for aerosol-generating substrates having relatively low aerosol former contents.

[0088] In another preferred embodiment, the aerosol-generating substrate is in the form of an aerosol-generating film comprising a cellulosic film-forming agent, nicotine, and an aerosol former. The aerosol-generating film may further comprise a cellulosic reinforcing agent. The aerosol-generating film may further comprise less than 30 weight percent water.

[0089] The term "film" as used herein is used to describe a solid layered element having a thickness smaller than its width or length. The film can be self-supporting. In other words, even if the film is obtained by casting a film-forming formulation on a support surface, it can have cohesive and mechanical properties that allow it to be separated from the support surface. Alternatively, the film can be placed on a support or sandwiched between other materials. This can enhance the mechanical stability of the film.

[0090] The aerosol-forming film has an aerosol-forming content within the ranges defined above for aerosol-forming substrates having relatively high aerosol-forming content.

[0091] In the context of the present invention, the term "cellulosic film former" is used to describe a cellulose polymer capable of forming a continuous film by itself or in the presence of an auxiliary thickener. Preferably, the cellulose film former is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and combinations thereof. In a particularly preferred embodiment, the cellulose film former is HPMC.

[0092] The aerosol-generating film may have a cellulosic film-forming agent content of from 10 weight percent to 40 weight percent, or from 15 weight percent to 35 weight percent, or from 20 weight percent to 30 weight percent on a dry weight basis.

[0093] Preferably, the aerosol-generating film further comprises a cellulosic reinforcing agent, preferably selected from the group consisting of cellulose fibers, microcrystalline cellulose (MCC), and cellulose powder, and combinations thereof.

[0094] The aerosol-generating film may have a cellulosic reinforcement content of from 0.5 weight percent to 40 weight percent on a dry weight basis, or from 5 weight percent to 30 weight percent on a dry weight basis, or from 10 weight percent to 25 weight percent on a dry weight basis.

[0095] The aerosol-generating film may further comprise carboxymethylcellulose, preferably sodium carboxymethylcellulose. The aerosol-generating film may have a carboxymethylcellulose content of from 1 to 15 percent by weight, or from 2 to 12 percent by weight, or from 4 to 10 percent by weight, on a dry weight basis.

[0096] Preferably, the aerosol-generating film comprises nicotine. As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salts. In embodiments where the aerosol-generating film comprises nicotine base or nicotine salts, the amounts of nicotine recited herein are the amounts of free base nicotine or the amounts of protonated nicotine, respectively.

[0097] The aerosol-generating film may contain natural or synthetic nicotine.

[0098] The aerosol-generating film may include one or more monobasic nicotine salts. As used herein in connection with the present invention, the term "monobasic nicotine salt" is used to describe a nicotine salt of a monobasic acid.

[0099] Preferably, the aerosol-generating film comprises, on a dry weight basis, 0.5 to 10 weight percent nicotine, or 1 to 8 weight percent nicotine, or 2 to 6 weight percent nicotine.

[0100] The aerosol-generating film may be a substantially tobacco-free aerosol-generating film.

[0101] In a preferred embodiment, the aerosol-generating film comprises an acid. More preferably, the aerosol-generating film comprises one or more organic acids. Even more preferably, the aerosol-generating film comprises one or more carboxylic acids. In a particularly preferred embodiment, the acid is lactic acid, benzoic acid, fumaric acid, or levulinic acid.

[0102] The aerosol-generating film preferably comprises, on a dry weight basis, 0.25 to 3.5 weight percent acid, or 0.5 to 3 weight percent acid, or about 1 to 2.5 weight percent acid.

[0103] In preferred embodiments, the aerosol-generating film has a thickness of about 0.1 millimeter to about 1 millimeter, more preferably about 0.1 millimeter to about 0.75 millimeter, and even more preferably about 0.1 millimeter to about 0.5 millimeter. In particularly preferred embodiments, a layer of the film-forming composition is formed having a thickness of about 50 micrometers to 400 micrometers, more preferably about 100 micrometers to 200 micrometers.

[0104] The aerosol-generating film may optionally be provided within the aerosol-generation segment on a suitable carrier element.

[0105] In an alternative embodiment of the present invention, the aerosol-generating substrate may comprise a gel composition comprising nicotine, at least one gelling agent, and an aerosol former. Preferably, the gel composition is substantially tobacco-free.

[0106] The preferred weight ranges of nicotine in the gel composition are the same as those defined above in connection with the aerosol-generating film.

[0107] The gel composition preferably comprises at least 50 weight percent aerosol former, more preferably at least 60 weight percent, more preferably at least 70 weight percent aerosol former, on a dry weight basis. The gel composition may comprise up to 80 weight percent aerosol former. The aerosol former in the gel composition is preferably glycerol.

[0108] The gel composition preferably includes at least one gelling agent in a total amount ranging from about 0.4 weight percent to about 10 weight percent, or from about 0.5 weight percent to about 8 weight percent, or from about 1 weight percent to about 6 weight percent, or from about 2 weight percent to about 4 weight percent, or from about 2 weight percent to about 3 weight percent.

[0109] The term "gelling agent" refers to a compound that, when homogeneously added in an amount of about 0.3 weight percent to a 50 weight percent water / 50 weight percent glycerol mixture, forms a solid medium or support matrix leading to a gel. Gelling agents include, but are not limited to, hydrogen-bond cross-linking gelling agents and ionic cross-linking gelling agents.

[0110] The term "hydrogen-bond cross-linking gelling agent" refers to a gelling agent that forms non-covalent or physical cross-links via hydrogen bonds. The hydrogen-bond cross-linking gelling agent may include one or more of galactomannan, gelatin, agarose, or konjac gum, or agar. Preferably, the hydrogen-bond cross-linking gelling agent includes agar.

[0111] The term "ionically cross-linked gelling agent" refers to a gelling agent that forms non-covalent or physical cross-links via ionic bonds. Ionically cross-linked gelling agents may include low acyl gellan, pectin, kappa carrageenan, iota carrageenan, or alginate. Preferably, the ionic cross-linked gelling agent may include low acyl gellan.

[0112] The gelling agent may comprise one or more biopolymers, which may be formed from polysaccharides.

[0113] Examples of biopolymers include gellan gum (natural gellan gum, low acyl gellan gum, high acyl gellan gum, and low acyl gellan gum are preferred), xanthan gum, alginate (alginic acid), agar, and guar gum. It may be preferable for the composition to include xanthan gum. The composition may include two biopolymers. The composition may include three biopolymers. The composition may include two biopolymers in substantially equal amounts by weight. The composition may also include three biopolymers in substantially equal amounts by weight.

[0114] The gel composition may further comprise a thickening agent. The thickening agent in combination with the hydrogen-bond cross-linking gelling agent and the ionic cross-linking gelling agent surprisingly appears to support a solid medium and maintain the gel composition even when the gel composition contains high levels of glycerol.

[0115] The term "thickener" refers to a compound that, when uniformly added in an amount of 0.3 percent by weight to a 50 percent by weight water / 50 percent by weight glycerol mixture at 25°C, increases the viscosity without resulting in the formation of a gel, and causes the mixture to remain in a fluid state or to remain fluid.

[0116] The gel composition preferably comprises a thickener in the range of about 0.2 weight percent to about 5 weight percent, or about 0.5 weight percent to about 3 weight percent, or about 0.5 weight percent to about 2 weight percent, or about 1 weight percent to about 2 weight percent.

[0117] The thickening agent may comprise one or more of xanthan gum, carboxymethylcellulose, microcrystalline cellulose, methylcellulose, gum arabic, guar gum, lambda carrageenan, or starch. Preferably, the thickening agent may comprise xanthan gum.

[0118] The gel composition may further comprise a divalent cation. Preferably, the divalent cation comprises calcium ions, such as calcium lactate in solution. The divalent cation (e.g., calcium ions) may aid in gel formation in compositions that include a gelling agent, such as an ionically crosslinking gelling agent. Ionic effects may aid gel formation. The divalent cation may be present in the gel composition in a range of about 0.1 to about 1 weight percent, or about 0.5 weight percent.

[0119] The gel composition may further comprise an acid. The acid may comprise a carboxylic acid, such as levulinic acid or lactic acid.

[0120] The gel composition preferably contains some water. When the composition contains some water, the gel composition is more stable. Preferably, the gel composition contains about 8 weight percent to about 32 weight percent water, or about 15 weight percent to about 25 weight percent water, or about 18 weight percent to about 22 weight percent water, or about 20 weight percent water.

[0121] Preferably, when a gel composition is used, the aerosol-generating substrate comprises a porous medium filled with the gel composition. The term "porous" is used herein to refer to a material that provides a plurality of pores or openings that allow the passage of air through the material.

[0122] In certain embodiments of the present invention, the aerosol-generating article further comprises one or more elongated susceptor elements within the rod of the aerosol-generating substrate, for example, the one or more elongated susceptor elements may be disposed substantially longitudinally within the rod of the aerosol-generating substrate and in thermal contact with the aerosol-generating substrate.

[0123] As used herein with respect to the present invention, the term "susceptor element" refers to a material capable of converting electromagnetic energy into heat. When located within a varying electromagnetic field, induced eddy currents in the susceptor element cause the susceptor element to heat. Because the susceptor element is located in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the susceptor element.

[0124] The term "elongated" when used to describe a susceptor element means that the susceptor element has a length dimension that is greater than its width dimension or its thickness dimension, for example, more than twice its width dimension or its thickness dimension.

[0125] The susceptor elements are disposed substantially longitudinally within the rod of the aerosol-generating substrate. This means that the length dimension of the elongated susceptor elements is disposed approximately parallel to the longitudinal axis of the rod, for example, within ±10 degrees of parallel to the longitudinal axis of the rod. In a preferred embodiment, the elongated susceptor elements may be positioned at a radially central position within the rod or segment, extending along the longitudinal axis of the rod or segment.

[0126] The susceptor elements are preferably in the form of pins, rods, strips, or blades.

[0127] The susceptor element preferably has a width of between 1 millimeter and 5 millimeters.

[0128] The susceptor 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 susceptor element preferably has a thickness of 10 micrometers to 500 micrometers, more preferably 10 micrometers to 100 micrometers.

[0129] Preferably, the elongate susceptor elements have a length that is the same as or shorter than the length of the aerosol-generating substrate in which they are incorporated. Preferably, the elongate susceptor elements have the same length as the aerosol-generating substrate in which they are incorporated.

[0130] The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-generating substrate. Preferred susceptor elements include metal or carbon.

[0131] Preferred susceptor elements may include or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or ferromagnetic steel or stainless steel, etc. Suitable susceptor elements may be or include aluminum.

[0132] Preferably, the rod of aerosol-generating substrate is surrounded by a wrapper, which may be a paper wrapper or a non-paper wrapper.

[0133] Suitable paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, cigarette paper and filter plug wrap. Suitable non-paper wrappers 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 material.

[0134] The aerosol-generating article according to the present disclosure may further comprise an upstream section located upstream of the rod of the aerosol-generating substrate. The upstream section is preferably located immediately upstream of the rod of the aerosol-generating substrate. The upstream section preferably extends between the upstream end of the aerosol-generating article and the rod of the aerosol-generating substrate. The upstream section may comprise one or more upstream elements located upstream of the rod of the aerosol-generating substrate.

[0135] The upstream element advantageously prevents direct physical contact of the aerosol-generating substrate with the upstream end of the rod. Furthermore, the presence of the upstream element helps to prevent any loss of the substrate, which may be advantageous, for example, when the substrate contains particulate plant material.

[0136] Where the rod of aerosol-generating substrate contains shredded tobacco, such as tobacco cut filler, the upstream section or element thereof may additionally serve to prevent loss of loose tobacco particles from the upstream end of the article, which may be particularly important, for example, when the shredded tobacco has a relatively low density.

[0137] The upstream element may be a porous plug element. Preferably, the upstream element has a porosity of at least 50 percent along the longitudinal axis of the aerosol-generating article. More preferably, the upstream element has a porosity of between 50 percent and 90 percent along the longitudinal axis. The porosity of the upstream element along the longitudinal axis is defined as the ratio of the cross-sectional area of ​​the material forming the upstream element to the internal cross-sectional area of ​​the aerosol-generating article at the location of the upstream element.

[0138] The upstream element may be made of a porous material or may include a plurality of openings, which may be achieved, for example, by laser drilling, and the plurality of openings are preferably uniformly distributed across the cross section of the upstream element.

[0139] The porosity or permeability of the upstream element may advantageously be designed to provide an aerosol-generating article with a particular overall resistance to draw (RTD) without substantially affecting the filtration provided by other portions of the article.

[0140] The upstream element may be formed from a material that is impermeable to air. In such embodiments, the aerosol-generating article may be configured to allow air to flow into the rod of aerosol-generating substrate through suitable venting means provided in the wrapper.

[0141] The upstream element may have a density of less than 200 grams per cubic centimeter, or less than 175 grams per cubic centimeter, or less than 150 grams per cubic centimeter. Preferably, the upstream element has a density of less than 140 grams per cubic centimeter. Preferably, the upstream element has a density of less than 138 grams per cubic centimeter, more preferably less than 136 grams per cubic centimeter, more preferably less than 134 grams per cubic centimeter, more preferably less than 132 grams per cubic centimeter, more preferably less than 130 grams per cubic centimeter.

[0142] More preferably, the upstream element has a density of at least 85 milligrams per cubic centimeter, more preferably at least 90 milligrams per cubic centimeter, more preferably at least 95 milligrams per cubic centimeter, more preferably at least 100 milligrams per cubic centimeter, more preferably at least 105 milligrams per cubic centimeter, more preferably at least 110 milligrams per cubic centimeter, more preferably at least 120 milligrams per cubic centimeter.

[0143] For example, the upstream element may have a density of 85 milligrams / cubic centimeter to 140 grams / cubic centimeter, or 90 milligrams / cubic centimeter to 138 grams / cubic centimeter, or 95 milligrams / cubic centimeter to 136 grams / cubic centimeter, or 100 milligrams / cubic centimeter to 134 grams / cubic centimeter, or 105 milligrams / cubic centimeter to 132 grams / cubic centimeter, or 110 milligrams / cubic centimeter to 130 grams / cubic centimeter, or 120 milligrams / cubic centimeter to 130 milligrams / cubic centimeter.

[0144] A decrease in the density of the upstream element compared to the typical density of such elements increases the compressibility of the upstream element.

[0145] The upstream element is adapted to be compressible to a final density upon insertion of the upstream element and the rod of aerosol-generating substrate into the heated chamber of the aerosol-generating device. Preferably, the upstream element is adapted to be compressible to a final density of at least 1.1 times the initial density, more preferably at least 1.25 times the initial density, more preferably at least 1.5 times the initial density, more preferably at least 1.75 times the initial density, and more preferably at least 2 times the initial density. The upstream element may be compressible to a final density of up to 4 times the initial density.

[0146] For example, the upstream element may be adapted to be compressible to a final density of 1.1 to 4 times the initial density, or 1.25 to 4 times the initial density, or 1.5 to 4 times the initial density, or 1.75 to 4 times the initial density, or 2 to 4 times the initial density, or 1.1 to 3 times the initial density, or 1.25 to 3 times the initial density, or 1.5 to 3 times the initial density, or 1.75 to 3 times the initial density, or 2 to 3 times the initial density.

[0147] Preferably, the upstream element is adapted to be compressible to a final density of at least 100 milligrams per cubic centimeter, more preferably at least 110 milligrams per cubic centimeter, more preferably at least 120 milligrams per cubic centimeter, more preferably at least 125 milligrams per cubic centimeter, more preferably at least 130 milligrams per cubic centimeter, more preferably at least 135 milligrams per cubic centimeter, more preferably at least 140 milligrams per cubic centimeter.

[0148] Preferably, the upstream element is adapted to be compressible to a final density of less than 350 milligrams per cubic centimeter, more preferably less than 300 milligrams per cubic centimeter, more preferably less than 275 milligrams per cubic centimeter, more preferably less than 250 milligrams per cubic centimeter, more preferably less than 225 milligrams per cubic centimeter, more preferably less than 200 milligrams per cubic centimeter, more preferably less than 175 milligrams per cubic centimeter.

[0149] For example, the upstream element is adapted to be compressible to a final density of 100 milligrams / cubic centimeter to 350 milligrams / cubic centimeter, or 110 milligrams / cubic centimeter to 300 milligrams / cubic centimeter, or 120 milligrams / cubic centimeter to 275 milligrams / cubic centimeter, or 125 milligrams / cubic centimeter to 250 milligrams / cubic centimeter, or 130 milligrams / cubic centimeter to 225 milligrams / cubic centimeter, or 135 milligrams / cubic centimeter to 200 milligrams / cubic centimeter, or 140 milligrams / cubic centimeter to 175 milligrams / cubic centimeter.

[0150] The upstream element may be made of any suitable material for use in an aerosol-generating article that provides the desired degree of compressibility. Suitable materials for forming the upstream element include filter material, ceramic, polymeric material, cellulose acetate, cardboard, zeolite, or an aerosol-generating substrate.

[0151] In a preferred embodiment, the upstream element is formed from a fibrous filtering material, and most preferably, the upstream element is formed from a segment of cellulose acetate tow.

[0152] Preferably, the upstream element is formed of a fibrous filtration material having a denier per filament (dpf) of less than 12, or less than 8, or less than 4. More preferably, the denier per filament (dpf) is less than 3. Preferably, the fibrous filtration material has a denier per filament (dpf) of less than 2.9, more preferably less than 2.8, more preferably less than 2.7, and more preferably less than 2.6.

[0153] Preferably, the denier per filament (dpf) of the fibrous filtration material is at least 2, more preferably at least 2.1, more preferably at least 2.2, more preferably at least 2.3, and more preferably at least 2.4.

[0154] For example, the denier per filament (dpf) may be 2 to 12, or 2 to 8, or 2 to 4, or 2 to 3, or 2.1 to 2.9, or 2.2 to 2.8, or 2.3 to 2.7, or 2.4 to 2.6. The denier per filament may be about 2.5.

[0155] The denier per filament corresponds to the average denier of the individual fibers in the upstream element and is the weight in grams of a single fiber or filament having a length of 9000 meters. Therefore, in the present invention, the dpf value indicates the thickness of each individual fiber in the upstream element. The denier per single fiber is expressed in units of denier, with 1 denier equaling 1 gram per 9000 meters. The dpf of a filter or filter segment can be easily determined by measuring the weight and length of a representative sample of fibers from the filter or filter segment.

[0156] Thus, the fibrous filtration material forming the upstream element has a relatively low denier per filament, which further improves the compressibility of the upstream element.

[0157] Preferably, the upstream element is formed of a fibrous filtration material having a total denier of less than 30,000, more preferably less than 25,000. The total denier may be about 20,000.

[0158] The "total denier" of a filtration material defines the total weight in grams of 9000 meters of the combined fibers that form the filtration material. Thus, the total denier of a filter segment is equal to the denier per single fiber multiplied by the total number of fibers in the filter segment.

[0159] When the upstream element is formed of a fibrous filtration material, the fibrous filtration material preferably includes a filter plasticizer. The amount of filter plasticizer in the upstream element is less than 4 weight percent based on the total weight of the upstream element (excluding the wrapper), more preferably less than 3.9 weight percent, more preferably less than 3.8 weight percent, more preferably less than 3.7 weight percent, and more preferably less than 3.6 weight percent based on the total weight of the upstream element. The amount of filter plasticizer in the upstream element is preferably at least 3 weight percent, more preferably at least 3.1 weight percent, more preferably at least 3.2 weight percent, more preferably at least 3.3 weight percent, and more preferably at least 3.4 weight percent, based on the total weight of the upstream element.

[0160] For example, the upstream element may have a filter plasticizer content of 3 weight percent to 4 weight percent, or 3.1 weight percent to 3.9 weight percent, or 3.2 weight percent to 3.8 weight percent, or 3.3 weight percent to 3.7 weight percent, or 3.4 weight percent to 3.6 weight percent, based on the total weight of the upstream element. The upstream element may have a filter plasticizer content of about 3.5 weight percent, based on the total weight of the upstream element.

[0161] Therefore, the amount of filter plasticizer in the fibrous filtration material is relatively low, which further improves the compressibility of the upstream element. A relatively low level of filter plasticizer can also ensure that compression of the upstream element does not unacceptably increase the resistance to draw (RTD) of the upstream element. In general, maintaining a relatively low level of filter plasticizer advantageously allows for better control of the RTD as the upstream element compresses. Providing a higher level of filter plasticizer may make it more difficult to compress the upstream element, but it can also set up undesirable channels on the outside of the upstream element as it compresses, which would lead to an unacceptable decrease in overall RTD.

[0162] Suitable filter plasticizers for use in the upstream element of the aerosol-generating article of the present invention are known to those skilled in the art. Preferably, the filter plasticizer is triacetin. Preferably, the upstream element comprises cellulose acetate tow containing triacetin as the filter plasticizer.

[0163] The upstream element may alternatively be formed from cardboard or paper material.

[0164] In certain preferred embodiments, the upstream element is formed of a solid, cylindrical plug element having a filled cross-section. Such a plug element may be referred to as a "plain" element. The solid plug element may be porous, but does not have a tubular configuration and therefore does not provide a longitudinal flow channel. Preferably, the solid plug element has a substantially uniform cross-section.

[0165] In such embodiments, the upstream element preferably has a resistance to withdrawal (RTD) of less than 25 millimeters of H2O, or less than 22 millimeters of H2O, or less than 20 millimeters of H2O. Preferably, in such embodiments, the upstream element has an RTD of at least 10 millimeters of H2O, or at least 12 millimeters of H2O, or at least 14 millimeters of H2O, or at least 16 millimeters of H2O. For example, the upstream element may have an RTD of between 10 millimeters of H2O and 25 millimeters of H2O, or between 12 millimeters of H2O and 22 millimeters of H2O, or between 14 millimeters of H2O and 20 millimeters of H2O, or between 16 millimeters of H2O and 20 millimeters of H2O.

[0166] In other embodiments, the upstream element is formed from a hollow tubular segment defining a longitudinal cavity that provides an unrestricted flow channel. In such embodiments, the upstream element provides protection for the aerosol-generating substrate, as described above, while having minimal effect on the overall resistance to draw (RTD) and filtration properties of the article.

[0167] Preferably, the diameter of the longitudinal cavity of the hollow tubular segment forming the upstream element is at least about 4 millimeters, more preferably at least about 4.5 millimeters, more preferably at least about 5 millimeters, more preferably at least about 5.5 millimeters. Preferably, the diameter of the longitudinal cavity is maximized to minimize the RTD of the upstream section or its upstream element. The inner diameter of the upstream element may be about 5.1 mm.

[0168] Preferably, the wall thickness of the hollow tubular segment is less than about 2 millimeters, more preferably less than about 1.5 millimeters, more preferably less than about 1.25 millimeters. The wall thickness of the hollow tubular segment defining the upstream element may be about 1 mm.

[0169] In such embodiments, the upstream element preferably has an RTD of less than 10 millimeters HO, more preferably less than 5 millimeters HO, and more preferably less than 2.5 millimeters HO. In such embodiments, the upstream element has an RTD of at least 0.1 millimeters HO, or at least about 0.25 millimeters HO, or at least about 0.5 millimeters HO. For example, the upstream element may have an RTD of between 0.1 millimeters HO and 10 millimeters HO, or between 0.25 millimeters HO and 5 millimeters HO, or between 0.5 millimeters HO and 2.5 millimeters HO.

[0170] Preferably, prior to insertion of the aerosol-generating article into the aerosol-generating device, the upstream element has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. Preferably, the outer diameter of the upstream element before compression is between 6 mm and 8 mm, more preferably between 7 mm and 7.5 mm. Preferably, the upstream element has an outer diameter of about 7.1 mm.

[0171] Preferably, the upstream element has a length of 2 to 8 millimeters, more preferably 3 to 7 millimeters, and more preferably 4 to 6 millimeters. In a particularly preferred embodiment, the upstream element has a length of about 5 millimeters. The length of the upstream section or element may be advantageously varied to provide a desired overall length for 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 element may be increased to maintain the same overall length of the article.

[0172] Additionally, for articles intended to be externally heated, the length of the upstream element can be used to control the position of the aerosol-generating article within the heating chamber of the aerosol-generating device, which can advantageously ensure that the position of the aerosol-generating substrate within the heating chamber can be optimized for heating, as well as the position of any ventilation.

[0173] The upstream element is preferably surrounded by a wrapper, such as plug wrap, that is preferably adapted to allow the necessary compression of the upstream element when the aerosol-generating article is inserted into the aerosol-generating device.

[0174] Preferably, the upstream element is surrounded by a wrapper having a thickness of less than 50 microns, more preferably less than 45 microns, more preferably less than 40 microns, more preferably less than 35 microns, more preferably less than 30 microns.

[0175] Preferably, the upstream element is surrounded by a wrapper having a basis weight of less than 35 grams per square meter, more preferably less than 30 grams per square meter, more preferably less than 25 grams per square meter, more preferably less than 20 grams per square meter.

[0176] Therefore, the wrapper surrounding the upstream element preferably has a relatively low thickness and basis weight to allow for the required level of compression of the upstream element.

[0177] The upstream element is preferably connected to the rod of the aerosol-generating substrate, and optionally to at least part of the downstream section, by an outer wrapper as described herein, which also preferably has a relatively low thickness and basis weight to allow the necessary level of compression of the upstream element and the aerosol-generating substrate.

[0178] Preferably, the outer wrapper has a thickness of less than 75 microns, more preferably less than 70 microns, more preferably less than 65 microns, more preferably less than 60 microns, more preferably less than 55 microns.

[0179] Preferably, the upstream element is surrounded by a wrapper having a basis weight of less than 50 grams per square meter, more preferably less than 45 grams per square meter, more preferably less than 40 grams per square meter, more preferably less than 35 grams per square meter.

[0180] The aerosol-generating article of the aerosol-generating system according to the present invention preferably further comprises a downstream section located downstream of the rod of the aerosol-generating substrate. The downstream section is preferably located immediately downstream of the rod of the aerosol-generating substrate. The downstream section of the aerosol-generating article preferably extends between the rod of the aerosol-generating substrate and the downstream end of the aerosol-generating article. The downstream section may comprise one or more elements, each of which is described in more detail within this disclosure.

[0181] The length of the downstream section may be between 20 millimeters and 70 millimeters, or between 25 millimeters and 60 millimeters, or between 30 millimeters and 50 millimeters.

[0182] The downstream section preferably comprises a hollow tubular cooling element provided downstream of the rod of aerosol-generating substrate, which may advantageously provide the aerosol cooling element for the aerosol-generating article.

[0183] The hollow tubular cooling element may be provided immediately downstream of the rod of the aerosol-generating substrate. In other words, the hollow tubular cooling element may abut the downstream end of the rod of the aerosol-generating substrate. The hollow tubular cooling element may define the upstream end of the 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 embodiments, the downstream section comprises two or more hollow tubular elements, as described below.

[0184] As used throughout this disclosure, the term "hollow tubular element" generally refers to an elongated element that defines a lumen or airflow passageway along its longitudinal axis.

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

[0186] The RTD of the hollow tubular cooling element is preferably 10 millimeters H2O or less, or 5 millimeters H2O or less, or 2.5 millimeters H2O or less, or 2 millimeters H2O or less, or 1 millimeter H2O or less.

[0187] The RTD of the hollow tubular cooling element can be at least 0 millimeters H2O, or at least 0.25 millimeters H2O, or at least 0.5 millimeters H2O, or at least 1 millimeter H2O.

[0188] Therefore, the flow channels should not include any components that would impede the longitudinal air flow. It is preferred that the flow channels are substantially empty, and it is particularly preferred that the flow channels are empty.

[0189] The aerosol-generating article may include a ventilation zone at a location along the downstream section. In some embodiments, the aerosol-generating article may include a ventilation zone at a location along the hollow tubular cooling element. Such a ventilation zone, or any ventilation zone, may extend through the peripheral wall of the hollow tubular cooling element. In this manner, fluid communication is established between the flow channel defined internally by the hollow tubular cooling element and the external environment. Ventilation zones are described further within this disclosure.

[0190] The length of the hollow tubular cooling element may be 15 mm to 50 mm, or 20 mm to 45 mm, or 20 mm to 40 mm, or 20 mm to 30 mm, or 25 mm to 40 mm, or 30 mm to 40 mm.

[0191] The wall thickness of the hollow tubular cooling element may be between 100 micrometers and 2 millimeters, or between 150 micrometers and 1.5 millimeters, or between 200 micrometers and 1.25 millimeters.

[0192] The hollow tubular cooling element preferably has an outer diameter approximately equal to the outer diameter of the rod of the aerosol-generating substrate and the outer diameter of the aerosol-generating article.

[0193] Preferably, the outer diameter of the hollow tubular cooling element is between 5 and 12 millimeters, more preferably between 6 and 10 millimeters, and more preferably between 7 and 8 millimeters. In some embodiments, the outer diameter of the hollow tubular cooling element is less than 7 millimeters, for example, between 5 and 7 millimeters, or between 6 and 7 millimeters.

[0194] Preferably, the hollow tubular cooling element may have a constant inner diameter along the length of the hollow tubular cooling element. However, the inner diameter of the hollow tubular cooling element may vary along the length of the hollow tubular cooling element.

[0195] 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.

[0196] The hollow tubular cooling element may have an inner diameter of 10 millimeters or less. For example, the hollow tubular cooling element may have an inner diameter of 9 millimeters or less, 8 millimeters or less, or 7 millimeters or less.

[0197] 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.

[0198] 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.

[0199] 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 a very stiff paper. The paper may be a crimped paper, such as crimped heat-resistant paper or crimped parchment paper.

[0200] Preferably, the hollow tubular cooling element may comprise cardboard. The hollow tubular cooling element may be a cardboard tube. The hollow tubular cooling element may be formed from cardboard.

[0201] The hollow tubular cooling element can be a paper tube. The hollow tubular cooling element can be a tube formed from spirally wound paper. The hollow tubular cooling element can be formed from multiple layers of paper. The paper can 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.

[0202] 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.

[0203] When the hollow tubular cooling element comprises cellulose acetate tow, the cellulose acetate tow can have a denier per filament of 2 to 4 and a total denier of 25,000 to 40,000.

[0204] In some embodiments, the aerosol-generating article of an aerosol-generating system according to the invention may include a ventilation zone at a location along the downstream section. More particularly, in those embodiments in which the downstream section comprises a hollow tubular cooling element, a ventilation zone may be provided at a location along the hollow tubular cooling element.

[0205] A ventilation zone typically includes a plurality of perforations through the peripheral wall of the hollow tubular cooling element. Preferably, the ventilation zone includes at least one circumferential row of perforations. In some embodiments, the ventilation zone may include two circumferential rows of perforations. For example, the perforations may be formed online during the manufacture of the aerosol-generating article. Preferably, each circumferential row of perforations includes between 8 and 30 perforations.

[0206] The aerosol-generating article of the aerosol-generating system of the present invention may have a breathability level of at least 25 percent.

[0207] The term "ventilation level" is used throughout this specification to mean the volume ratio of the airflow entering the aerosol-generating article via the ventilation zone (ventilation airflow) to the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the greater the dilution of the aerosol stream delivered to the consumer. The aerosol-generating article preferably has a ventilation level of at least 25 percent, more preferably at least 30 percent, even more preferably at least 40 percent, and even more preferably at least 50 percent.

[0208] The aerosol-generating articles of the aerosol-generating systems of the present invention may have a breathability level of up to 90 percent. Preferably, the aerosol-generating articles according to the present invention have a breathability level of 80 percent or less, more preferably 70 percent or less, and even more preferably 60 percent or less.

[0209] For example, the aerosol-generating article of the aerosol-generating system of the present invention may have a breathability level of between 25 percent and 90 percent, preferably between 30 percent and 80 percent, more preferably between 40 percent and 70 percent, and even more preferably between 50 percent and 60 percent.

[0210] The downstream section may further include a downstream filter segment. The downstream filter segment may extend to the downstream end of the downstream section. The downstream filter segment may be located at the downstream end of the aerosol-generating article. The downstream end of the downstream filter segment may define the downstream end of the aerosol-generating article.

[0211] The downstream filter segment may be located downstream of the hollow tubular cooling element, as described above, and may extend between the hollow tubular cooling element and the downstream end of the aerosol-generating article.

[0212] The downstream filter segment is preferably a solid plug, which may also be described as a "plain" plug, and is non-tubular. Thus, the filter segment preferably has a substantially uniform cross-section.

[0213] The downstream filter segment is formed of a fibrous filter material. The fibrous filter material may be for filtering aerosols 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.

[0214] 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 in end-to-end abutting relationship with one another.

[0215] The downstream filter segment preferably has a low particle filtration efficiency.

[0216] The downstream filter segment is preferably surrounded by plug wrap. The downstream filter segment is preferably non-vented so that air does not enter the aerosol-generating article along the downstream filter segment.

[0217] The downstream filter segment is preferably connected to one or more of the adjacent upstream components of the aerosol-generating article by a tipping wrapper.

[0218] The downstream filter segment preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The outer diameter of the downstream filter segment may be substantially the same as the outer diameter of the hollow tubular cooling element.

[0219] Preferably, the outer diameter of the downstream filter segment is 5 to 12 millimeters, more preferably 6 to 10 millimeters, and more preferably 7 to 8 millimeters. In some embodiments, the outer diameter of the downstream filter segment may be less than 7 millimeters, for example, 5 to 7 millimeters, or 6 to 7 millimeters.

[0220] As described above, the downstream filter segment may be formed of a fibrous material. The downstream filter segment may be formed of a porous material. The downstream filter segment may be formed of a biodegradable material. The downstream filter segment may be formed of a cellulosic material, such as cellulose acetate.

[0221] The downstream filter segment may be formed of a polylactic acid-based material. The downstream filter segment may be formed of a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment may be made by injection molding or extrusion.

[0222] The length of the downstream filter segment may be between 5 millimeters and 25 millimeters, or between 10 millimeters and 25 millimeters, or between 5 millimeters and 20 millimeters, or between 10 millimeters and 20 millimeters.

[0223] The downstream section may further comprise one or more additional hollow tubular elements.

[0224] In certain embodiments, the downstream section may comprise a hollow tubular support element upstream of the hollow tubular cooling element described above. Preferably, the hollow tubular support element abuts the downstream end of the rod of the aerosol-generating substrate. Preferably, the hollow tubular support element abuts the upstream end of the hollow tubular cooling element. Preferably, the hollow tubular support element and the hollow tubular cooling element are adjacent to each other and together provide a hollow tubular section within the downstream section.

[0225] Preferably, the hollow tubular support element is compressible.

[0226] 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, crimped paper (such as crimped heat-resistant paper or crimped 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.

[0227] The hollow tubular support element preferably has an outer diameter approximately equal to the outer diameter of the rod of the aerosol-generating substrate and the outer diameter of the aerosol-generating article.

[0228] Preferably, the outer diameter of the hollow tubular support element is between 5 and 12 millimeters, more preferably between 6 and 10 millimeters, and more preferably between 7 and 8 millimeters. In some embodiments, the outer diameter of the hollow tubular support element is less than 7 millimeters, for example, between 5 and 7 millimeters, or between 6 and 7 millimeters.

[0229] The hollow tubular support element may have a wall thickness of at least 1 millimeter, preferably at least 1.5 millimeters, more preferably at least 2 millimeters.

[0230] The hollow tubular support element may have a length of 5 mm to 15 mm, preferably 6 mm to 15 mm, and more preferably 7 mm to 15 mm. In other embodiments, the support element has a length of 5 mm to 12 mm, preferably 6 mm to 12 mm, and more preferably 7 mm to 12 mm. In further embodiments, the support element has a length of 5 mm to 10 mm, preferably 6 mm to 10 mm, and more preferably 7 mm to 10 mm.

[0231] Preferably, the hollow tubular support element is adapted to be as compressible as the rod of aerosol-generating substrate, thereby enabling at least the upstream portion of the hollow tubular support element to be compressed in order to insert the aerosol-generating article into the heating device. Partial compression of the hollow tubular support element may be required in aerosol-generating systems in which the rod of aerosol-generating substrate is fully received within the heating chamber, and the upstream end of the hollow tubular segment may also be received within the heating chamber.

[0232] Preferably, the hollow tubular support element comprises a peripheral wall having a density of less than 200 milligrams per cubic centimeter, more preferably less than 175 milligrams per cubic centimeter, more preferably less than 150 milligrams per cubic centimeter, more preferably less than 140 milligrams per cubic centimeter, more preferably less than 130 milligrams per cubic centimeter.

[0233] As an alternative or in addition to the hollow tubular support element, the downstream section may further comprise a downstream hollow tubular element downstream of the hollow tubular cooling element.

[0234] The overall RTD after insertion of the aerosol-generating article into the aerosol-generating device is preferably at least 10 millimeters HO, more preferably at least 15 millimeters HO, more preferably at least 20 millimeters HO, more preferably at least 25 millimeters HO, more preferably at least 30 millimeters HO.

[0235] Preferably, the overall RTD of the aerosol-generating article after insertion into the aerosol-generating device is 70 millimeters HO or less, more preferably 60 millimeters HO or less, more preferably 55 millimeters HO or less, more preferably 50 millimeters HO or less, and more preferably 45 millimeters HO or less.

[0236] For example, the overall RTD of the aerosol-generating article after insertion into the aerosol-generating device may be between 10 millimeters HO and 70 millimeters HO, or between 15 millimeters HO and 60 millimeters HO, or between 20 millimeters HO and 55 millimeters HO, or between 25 millimeters HO and 45 millimeters HO, or between 30 millimeters HO and 45 millimeters HO.

[0237] The aerosol-generating article preferably has a total length of 40 millimeters to 80 millimeters, or 40 millimeters to about 70 millimeters, or 40 millimeters to about 60 millimeters, or 45 millimeters to about 80 millimeters, or about 45 millimeters to about 70 millimeters, or 45 millimeters to 60 millimeters, or 50 millimeters to 80 millimeters, or 50 millimeters to about 70 millimeters, or about 50 millimeters to about 60 millimeters. In an exemplary embodiment, the total length of the aerosol-generating article is about 45 millimeters.

[0238] The aerosol-generating article preferably has an outer diameter of from about 5 mm to about 12 mm, or from about 6 mm to about 12 mm, or from about 7 mm to about 12 mm, or from about 5 mm to about 10 mm, or from about 6 mm to about 10 mm, or from about 7 mm to about 10 mm, or from about 5 mm to about 8 mm, or from about 6 mm to about 8 mm, or from about 7 mm to about 8 mm. In other embodiments, the aerosol-generating article has an outer diameter of less than 7 mm.

[0239] The outer diameter of the aerosol-generating article may be substantially constant along the entire length of the article before insertion of the aerosol-generating article into the aerosol-generating device. Alternatively, different portions of the aerosol-generating article may have different outer diameters. In particular, the rod of the aerosol-generating substrate may have different outer diameters after insertion of the aerosol-generating article into the aerosol-generating device.

[0240] In a particularly preferred embodiment, one or more of the components of the aerosol-generating article are individually enclosed by their own wrapper.

[0241] Preferably, at least one of the components of the aerosol-generating article is enclosed in a hydrophobic wrapper.

[0242] The term "hydrophobicity" refers to a surface that exhibits water-repellent properties. One useful way to determine this is to measure the water contact angle. The "water contact angle" is the angle traditionally measured through a liquid where the liquid / vapor interface meets a solid surface. It quantifies the wettability of a solid surface by a liquid via Young's equation. Hydrophobicity or water contact angle may be determined by utilizing the TAPPI T558 test method, and the results are expressed as interfacial contact angles, reported in degrees, which can range from approximately zero to approximately 180 degrees.

[0243] In preferred embodiments, the hydrophobic wrapper comprises a paper layer having a water contact angle of about 30 degrees or greater, preferably about 35 degrees or greater, or about 40 degrees or greater, or about 45 degrees or greater.

[0244] By way of example, the paper layer may comprise PVOH (polyvinyl alcohol) or silicone. The PVOH may be applied to the paper layer as a surface coating, or the paper layer may comprise a surface treatment that includes PVOH or silicone.

[0245] The aerosol-generating system according to the present invention further comprises an aerosol-generating device for heating the aerosol-generating substrate of the aerosol-generating article during use, as defined above. The aerosol-generating article is adapted to be inserted into the aerosol-generating device by a consumer. The aerosol-generating device comprises a body defining a heating chamber for removably receiving at least a portion of the rod of the aerosol-generating substrate when the aerosol-generating article is inserted into the aerosol-generating device. The heating chamber comprises a heater assembly disposed along at least a portion of the heating chamber for heating the rod of the aerosol-generating substrate.

[0246] As used herein with respect to the present invention, the term "heater assembly" refers to a component of an aerosol-generating device that is responsible for heating the aerosol-generating substrate of an aerosol-generating article. As explained in more detail below, the heater assembly may directly heat the aerosol-generating substrate, which may be the case when the heater assembly includes a resistive heater. The heater assembly may indirectly heat the aerosol-generating substrate, which may be the case when the heater assembly includes an induction coil.

[0247] The heating chamber of the aerosol-generating device may include an open downstream end and a closed upstream end. In use, the upstream end of the aerosol-generating device may be inserted into the open downstream end of the heating chamber. In use, the upstream end of the aerosol-generating article may abut against the upstream end of the heating chamber. Alternatively, the upstream end of the aerosol-generating article may abut against another component within the heating chamber to prevent the aerosol-generating article from moving further upstream.

[0248] As used herein with respect to the present invention, the term "fully received" refers to the position at which the aerosol-generating article is inserted as far as possible into the heating chamber. This may be when the upstream end of the aerosol-generating article abuts the upstream end of the heating chamber. Alternatively, this may be when the upstream end of the aerosol-generating article abuts another component within the heating chamber, preventing the aerosol-generating article from moving further upstream. When the aerosol-generating article is "fully received" within the heating chamber, a portion of the aerosol-generating article may protrude beyond the open downstream end of the aerosol-generating article. This may be the case, for example, when the length of the aerosol-generating article is greater than the length of the heating chamber, or when the length of the aerosol-generating article is greater than the distance between the downstream end of the heating chamber and a component within the heating chamber, which, if present, may prevent the aerosol-generating article from moving further upstream.

[0249] The length of the heating chamber may be 15 mm to 80 mm. The length of the heating chamber is preferably 20 mm to 70 mm. The length of the heating chamber is more preferably 25 mm to 60 mm. The length of the heating chamber is more preferably 25 mm to 50 mm.

[0250] The length of the heating chamber may be 25 to 29 millimeters. The length of the heating chamber is preferably 25 to 29 millimeters. The length of the heating chamber is more preferably 26 to 29 millimeters. The length of the heating chamber is even more preferably 27 or 28 millimeters.

[0251] The length of the heating chamber may be the same as or longer than the length of the rod of the aerosol-generating substrate. The length of the heating chamber is preferably such that, when the aerosol-generating article is received in the heating chamber, at least 75 percent of the rod of the aerosol-generating substrate is inserted or received within the heating chamber of the device. More preferably, the length of the heating chamber is such that, when the aerosol-generating article is fully received in the heating chamber, at least 80 percent of the rod of the aerosol-generating substrate is inserted or received within the heating chamber. More preferably, the length of the heating chamber is such that, when the aerosol-generating article is fully received in the heating chamber, at least 90 percent of the rod of the aerosol-generating substrate is inserted or received within the heating chamber. This maximizes the length of the rod of the aerosol-generating substrate that can heat the aerosol-generating substrate during use, thereby optimizing aerosol generation from the aerosol-generating substrate and reducing waste.

[0252] The length of the heating chamber may be such that when the aerosol-generating article is completely received within the heating chamber, the downstream section, or a portion thereof, protrudes from the heating chamber.The length of the heating chamber may be such that when the aerosol-generating article is completely received within the heating chamber, a portion of the downstream section is received within the heating chamber.

[0253] As defined above, the heating chamber is configured to deform or distort the rod of aerosol-generating substrate upon insertion of the aerosol-generating article into the aerosol-generating device. Accordingly, the shape and size of the heating chamber are configured according to the shape and size of the rod of aerosol-generating substrate, so as to produce the desired deformation or distort of the aerosol-generating substrate upon insertion of the rod of aerosol-generating substrate into the heating chamber. In particular, the cross-sectional area of ​​the heating chamber is adapted so that insertion of the rod of aerosol-generating substrate into the heating chamber results in at least one of an increase in the density of the aerosol-generating substrate, a decrease in the cross-sectional area of ​​the aerosol-generating substrate, and an increase in the maximum diameter of the rod of aerosol-generating substrate.

[0254] The cross-sectional area of ​​the heating chamber is preferably smaller than the initial cross-sectional area of ​​the rod of the aerosol-generating substrate.

[0255] In a preferred embodiment of the present invention, the heating chamber includes a pair of opposing flat surfaces configured to receive the rod of the aerosol-generating substrate therebetween. The resulting heating assembly is preferably flat. The aerosol-generating device may also be flat. The opposing flat surfaces are preferably fixed relative to each other within the heating chamber. The heater assembly preferably includes a heater element provided on at least one of the opposing flat surfaces or adjacent to at least one flat surface. The heater assembly preferably includes a heater element provided on or adjacent each of the opposing flat surfaces so that the rod of the aerosol-generating substrate is heated from both sides. In such an arrangement, the heater assembly includes a pair of opposing heater elements that heat the rod of the aerosol-generating substrate from opposing sides. The opposing heater elements are also preferably flat to provide a flat heating assembly.

[0256] As used herein, the term "flat" refers to a feature that extends substantially in a two-dimensional plane. Defining the surface of the heating chamber as "flat" means that the surface of the heating chamber extends substantially in a two-dimensional plane. Thus, the surface has minimal curvature, and preferably no curvature. The use of a heating chamber including opposing flat surfaces on which the heater elements are provided increases the contact area between the heater elements and the rod of the aerosol-generating substrate, resulting in more efficient heating of the aerosol-generating substrate. The spacing of the opposing heater elements can also be adapted so that the distance between them is relatively small and heat can be transferred much more efficiently through the rod of the aerosol-generating substrate.

[0257] In such embodiments, the pair of opposing flat surfaces of the heating chamber are preferably substantially parallel to one another such that the spacing between the opposing flat surfaces is substantially the same along the length of the heating chamber, and thus the heating chamber preferably has a substantially rectangular transverse cross-section.

[0258] The average spacing between the pair of opposing flat surfaces of the heating chamber is preferably less than 5 millimeters, more preferably less than 4.5 millimeters, more preferably less than 4 millimeters, more preferably less than 3.5 millimeters, and more preferably less than 3 millimeters. The average spacing between the pair of opposing flat surfaces of the heating chamber is preferably at least 2 millimeters, more preferably at least 2.5 millimeters. Thus, the average spacing may be 2 millimeters to 5 millimeters, or 2 millimeters to 4.5 millimeters, or 2 millimeters to 4 millimeters, or 2 millimeters to 3.5 millimeters, or 2 millimeters to 3 millimeters, or 2.5 millimeters to 5 millimeters, or 2.5 millimeters to 4.5 millimeters, or 2.5 millimeters to 4 millimeters, or 2.5 millimeters to 3.5 millimeters, or 2.5 millimeters to 3 millimeters.

[0259] Thus, the average spacing between a pair of opposing surfaces of the heating chamber is typically much smaller than the rod diameter or maximum diameter of the aerosol-generating substrate prior to insertion into the aerosol-generating device.

[0260] Preferably, the average spacing between the pair of opposing surfaces of the heating chamber is at least 1 millimeter smaller than the maximum diameter of the rod of the aerosol-generating substrate before the aerosol-generating article is inserted into the aerosol-generating device. More preferably, the spacing between the pair of opposing surfaces of the heating chamber is at least 1.5 millimeters, or at least 2 millimeters, or at least 2.5 millimeters, or at least 3 millimeters smaller than the maximum diameter of the rod of the aerosol-generating substrate before the aerosol-generating article is inserted into the aerosol-generating device. The spacing between the opposing surfaces of the heating chamber may be up to 6 millimeters or up to 5 millimeters smaller than the maximum diameter of the rod of the aerosol-generating substrate before the aerosol-generating article is inserted into the aerosol-generating device.

[0261] The ratio of the initial outer diameter of the rod of the aerosol-generating substrate to the spacing between the pair of opposing surfaces of the heating chamber is preferably at least 1.5, more preferably at least 1.75, more preferably at least 2, and more preferably at least 2.25. This ratio indicates the degree of compression of the rod of the aerosol-generating substrate required to insert it into the heating chamber.

[0262] The heating chamber preferably includes a funnel-shaped portion at its open downstream end, which has a cross-sectional area that gradually decreases from the downstream end to the upstream end, which may advantageously facilitate insertion of the rod of aerosol-generating substrate into the heating chamber, and in particular the gradual compression or flattening of the rod of aerosol-generating substrate from its initial shape to its final compressed shape.

[0263] In another preferred embodiment of the present invention, the heating chamber may include a pair of movable walls, at least one of which includes a heater element on its inner surface. The movable walls are adapted to be movable relative to one another between an open position and a closed position. In the open position, the movable walls are spaced apart so that the rod of the aerosol-generating substrate can be inserted between them. The movable walls are then moved toward one another to a closed position, where the walls close around the rod of the aerosol-generating substrate. When the movable walls are closed in the closed position, the rod of the aerosol-generating substrate is held between the walls and in contact with its inner surface.

[0264] The movable wall is adapted to cause the desired compression and flattening of the rod of aerosol-generating substrate when the movable wall is closed. Thus, in such an embodiment, the rod of aerosol-generating substrate is compressed in a single step after insertion of the aerosol-generating article into the aerosol-generating device. This may facilitate insertion of the aerosol-generating article into the aerosol-generating device and compression of the rod of aerosol-generating substrate.

[0265] Preferably, in the closed position, the movable walls have an average spacing within the ranges given above for the embodiment in which a pair of flat opposing surfaces is provided within the heating chamber. The aerosol generating device is provided with means for locking the movable walls in the closed position during use, thereby maintaining the desired compression level during heating.

[0266] Preferably, the movable walls are connected to one another at one end to form a jaw-like arrangement that allows them to rotate relative to one another between open and closed positions, thereby optimizing the degree to which the movable walls open relative to one another to facilitate insertion of the aerosol-generating article into the aerosol-generating device.

[0267] The heater assembly may include a single heater element or multiple heater elements. Any suitable type of heater element may be used. The heater assembly may include at least one of a resistive heating element and an induction heating assembly. The heater assembly may include an external heater or external heating element.

[0268] The heater assembly may externally heat the rod of the aerosol-generating substrate when the aerosol-generating article is received within the aerosol-generating device. Such an external heater assembly may be provided on at least one side of the rod of the aerosol-generating substrate when received within the heating chamber of the aerosol-generating device. Preferably, external heater assemblies are provided that heat the rod of the aerosol-generating substrate from opposite sides, as described above.

[0269] The heater assembly may include at least one resistive heating element. The at least one resistive heating element may be any suitable type of resistive heating element. In some embodiments, the heater assembly includes only one resistive heating element. In some embodiments, the heater assembly includes multiple resistive heating elements. The heater may include at least one resistive heating element. Preferably, the heater assembly includes multiple resistive heating elements. The resistive heating elements are preferably electrically connected in a parallel arrangement. Advantageously, providing multiple resistive heating elements electrically connected in a parallel arrangement may facilitate delivery of desired power to the heater while reducing or minimizing the voltage required to provide the desired power. Advantageously, reducing or minimizing the voltage required to operate the heater may facilitate reducing or minimizing the physical size of the power supply.

[0270] In some embodiments, the at least one heating element comprises an electrically insulating substrate and the at least one resistive heating element is provided on the electrically insulating substrate.

[0271] In some embodiments, the heater assembly comprises an induction heating assembly. The induction heating assembly may comprise an inductor coil. The aerosol generating device may comprise a power source configured to provide a high frequency oscillating current to the inductor coil.

[0272] The heater assembly may include an induction heating element. The induction heating element may be a susceptor element. In these embodiments, the susceptor element is preferably located in contact with the aerosol-generating substrate. In some embodiments, the susceptor element is located within the aerosol-generating device. In these embodiments, the susceptor element may be located within a heating chamber. The aerosol-generating device may include only one susceptor element. The aerosol-generating device may include multiple susceptor elements. In some embodiments, the susceptor element is preferably positioned to heat the outer surface of the aerosol-generating substrate.

[0273] When the heater assembly includes both an induction coil and an induction heating element, the heating zone is defined as the longitudinal space between the upstream-most portion of the induction coil and the induction heating element, and the longitudinal space between the downstream-most portion of the induction coil and the induction heating element.

[0274] The susceptor elements may comprise any suitable material. Suitable materials for the elongated susceptor elements include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements comprise metal or carbon. Advantageously, the susceptor elements may comprise or consist of ferromagnetic materials, such as ferritic iron, ferromagnetic alloys such as ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite. Suitable susceptor elements may be or include aluminum.

[0275] As will be explained in more detail below, in some embodiments in which the aerosol-generating device comprises an induction coil, the aerosol-generating article may comprise at least one susceptor element.

[0276] In some embodiments, the aerosol generating device may comprise at least one resistive heating element and at least one inductive heating assembly, hi some embodiments, the aerosol generating device may comprise a combination of a resistive heating element and an inductive heating assembly.

[0277] The aerosol-generating device may include an airflow channeling extending between the channel inlet and the channel outlet. The airflow channel may be configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. The airflow channel of the aerosol-generating device may be defined within the body of the aerosol-generating device to enable fluid communication between the interior of the heating chamber and the exterior of the aerosol-generating device. When an aerosol-generating article is received within the heating chamber, the airflow channel may be configured to provide air flow into the article to deliver the generated aerosol to a user who inhales through the mouth end of the article.

[0278] The aerosol generating device may include a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. [Brief explanation of the drawings]

[0279] [Figure 1] FIG. 1 shows a schematic side perspective view of a first aerosol-generating article for use in an aerosol-generating system according to the present invention. [Figure 2] FIG. 2 shows a schematic cross-sectional side view of a first aerosol-generating article for use in an aerosol-generating system according to the present invention. [Figure 3] FIG. 3 shows a schematic side cross-sectional view of an aerosol generating device for use in an aerosol-generating article system according to the present invention. [Figure 4] FIG. 4 shows a schematic diagram of the compression of the rod of the aerosol-generating substrate of the aerosol-generating article of FIG. 1 when inserted into the heated chamber of an aerosol-generating device according to the first embodiment. [Figure 5] FIG. 5 shows a schematic diagram of compression of the rod of the aerosol-generating substrate of the aerosol-generating article of FIG. 1 when inserted into the heated chamber of an aerosol-generating device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0280] The following provides a non-exhaustive list of non-limiting examples, any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0281] Example 1 1. An aerosol generating system comprising: an aerosol-generating article comprising a rod of aerosol-generating substrate and a downstream section extending from a downstream end of the rod of aerosol-generating substrate to a mouth end of the aerosol-generating article; An aerosol generating system comprising: an aerosol generating device having a body defining a heating chamber for removably receiving at least a portion of a rod of an aerosol-generating substrate of an aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device; and a heater assembly disposed along at least a portion of the heating chamber for heating the rod of the aerosol-generating substrate when the aerosol-generating article is received in the aerosol-generating device. Example 2. 10. The aerosol generating system of claim 1, wherein the rod of aerosol-generating substrate has an initial density prior to insertion of the aerosol-generating article into the aerosol-generating device, and the cross-section of the heating chamber of the aerosol-generating device is configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final density that is at least 1.1 times the initial density. Example 3 3. An aerosol-generating system according to any one of claims 1 to 2, wherein the initial density of the rods of the aerosol-generating substrate is less than 300 milligrams per cubic centimeter. Example 4. An aerosol-generating system as described in Example 3, wherein the initial density of the rods of the aerosol-generating substrate is less than 150 milligrams per cubic centimeter. Example 5. The aerosol-generating system of Example 3, wherein the initial density of the rods of the aerosol-generating substrate is between 75 milligrams per cubic centimeter and 300 milligrams per cubic centimeter. Example 6 6. An aerosol-generating system according to any one of Examples 1 to 5, wherein the final density of the rods of the aerosol-generating substrate is at least twice its initial density. Example 7 7. The aerosol generating system of any one of Examples 1 to 6, wherein the final density is at least 300 milligrams per cubic centimeter. Example 8 8. The aerosol generating system of any one of Examples 1 to 7, having a final density of 150 milligrams per cubic centimeter to 500 milligrams per cubic centimeter. Example 9. 9. An aerosol generating system according to any one of Examples 1 to 8, wherein the rod of aerosol-generating substrate has an initial cross-sectional area prior to insertion of the aerosol-generating article into the aerosol-generating device, and the cross-sectional area of ​​the heating chamber of the aerosol-generating device is configured such that upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final cross-sectional area, and the initial cross-sectional area is at least 1.1 times the final cross-sectional area. Example 10. 10. An aerosol-generating system as described in Example 9, wherein the initial cross-sectional area of ​​the rod of the aerosol-generating substrate is at least 28 square millimeters. Example 11 11. An aerosol-generating system according to Example 10, wherein the rod of the aerosol-generating substrate has an initial cross-sectional area of ​​between 28 square millimeters and 50 square millimeters. Example 12 12. The aerosol generation system of any of Examples 9-11, wherein the initial cross-sectional area is at least twice the final cross-sectional area. Example 13 13. An aerosol generating system according to any one of Examples 7 to 12, wherein the final transverse cross-sectional area is less than 30 square millimeters. Example 14. 14. The aerosol generation system of Example 13, wherein the final cross-sectional area is between 10 square millimeters and 30 square millimeters. Example 15. 15. An aerosol generating system according to any one of Examples 1 to 14, wherein the rod of aerosol-generating substrate has an initial maximum diameter prior to insertion of the aerosol-generating article into the aerosol-generating device, and the cross-section of the heating chamber of the aerosol-generating device is configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed such that, after compression, the rod of aerosol-generating substrate has a final maximum diameter that is at least 1.1 times the initial maximum diameter. Example 16. The aerosol generating system described in Example 15 Example 17. An aerosol-generating article according to any one of Examples 1 to 16, wherein the rod of aerosol-generating substrate is adapted to be compressible to a final density of at least 300 milligrams per cubic centimeter. Example 18. 18. An aerosol-generating system according to any one of Examples 1 to 17, wherein the initial maximum diameter of the rod of the aerosol-generating substrate is less than 8.5 millimeters. Example 19. 19. The aerosol-generating system of Example 18, wherein the initial maximum diameter of the rod of the aerosol-generating substrate is between 6 millimeters and 8.5 millimeters. Example 20. 20. An aerosol-generating system according to any one of Examples 15 to 19, wherein the final maximum diameter of the rod of the aerosol-generating substrate may be at least 1.25 times its initial maximum diameter. Example 21. 21. An aerosol-generating system according to any one of Examples 15 to 20, wherein the final maximum diameter of the rod of the aerosol-generating substrate is at least 8 millimeters. Example 22. 22. The aerosol-generating system of claim 21, wherein the final maximum diameter of the rod of the aerosol-generating substrate is between 8 millimeters and 10.5 millimeters. Example 23. 23. An aerosol-generating system according to any one of Examples 1 to 22, wherein the rod of the aerosol-generating substrate has a substantially circular transverse cross-section prior to insertion of the aerosol-generating article into the aerosol-generating device. Example 24. 24. An aerosol-generating system according to any one of Examples 1 to 23, wherein the rod of the aerosol-generating substrate has a substantially rectangular transverse cross-section after insertion of the aerosol-generating article into the aerosol-generating device. Example 25. 25. The aerosol generating system of Example 24, wherein the width of the rectangle is preferably at least twice the height of the rectangle. Example 26. 26. The aerosol-generating system according to any one of Examples 1 to 25, wherein the aerosol-generating substrate comprises an aerosol-forming body. Example 27. 27. The aerosol-generating system of any one of Examples 1 to 26, wherein the aerosol-generating substrate comprises at least 40 weight percent aerosol former. Example 28. 28. An aerosol-generating system according to any one of claims 1 to 27, wherein the aerosol-generating substrate is substantially tobacco-free. Example 29. 28. An aerosol-generating system as claimed in any one of Examples 1 to 27, wherein the aerosol-generating substrate comprises homogenised tobacco material. Example 30. 28. The aerosol-generating system according to any one of Examples 1 to 27, wherein the aerosol-generating substrate comprises a cut filler. Example 31. 29. The aerosol-generating system of any of Examples 1 to 28, wherein the aerosol-generating substrate comprises an aerosol-generating film comprising a cellulosic film-forming agent, nicotine, and an aerosol former. Example 32. 29. The aerosol-generating system of any one of Examples 1 to 28, wherein the aerosol-generating substrate comprises a gel composition comprising nicotine, at least one gelling agent, and an aerosol former. Example 33. The aerosol-generating system of Example 32, wherein the gel composition is loaded onto a porous medium. Example 34. 34. The aerosol-generating system of any one of Examples 1 to 33, wherein the aerosol-generating article further comprises one or more elongated susceptor elements within the rod of the aerosol-generating substrate. Example 35. 35. An aerosol-generating system according to any one of Examples 1 to 34, wherein the downstream section of the aerosol-generating article comprises a compressible hollow tubular support element. Example 36. 36. An aerosol generation system as described in Example 35, wherein the hollow tubular support element has a peripheral wall having a density of less than 140 milligrams per cubic centimeter. Example 37. 37. An aerosol generation system as described in Example 35 or 36, wherein the downstream section further comprises a hollow tubular cooling element. Example 38. An aerosol-generating system as described in Example 37, wherein the aerosol-generating article further comprises a ventilation zone located along the hollow tubular cooling element. Example 39. 39. The aerosol generation system of any of Examples 35-38, wherein the downstream section further comprises a downstream filter segment. Example 40. 40. An aerosol-generating system according to any one of Examples 1 to 39, wherein the aerosol-generating article further comprises a compressible upstream element located upstream of the rod of the aerosol-generating substrate. Example 41. 41. An aerosol generation system as described in Example 40, wherein the compressible upstream element has a density of less than 140 milligrams per cubic centimeter. Example 42. 42. The aerosol generation system of example 40 or 41, wherein the upstream element is adapted to be compressible to a final density of at least 1.5 times the initial density. Example 43. 43. An aerosol generation system according to any one of Examples 40 to 42, wherein the upstream element is adapted to be compressible to a final density of at least 140 milligrams per cubic centimeter. Example 44. 44. An aerosol generating system according to any one of Examples 40 to 43, wherein the upstream element is formed of a fibrous filtering material. Example 45. 45. The aerosol generating system of example 44, wherein the fibrous filtration material has less than 3 denier per filament. Example 46. 46. ​​An aerosol generation system as described in Example 44 or 45, wherein the fibrous filtration material has a total denier of less than 30,000. Example 47. An aerosol generating system described in any of Examples 44 to 46, wherein the fibrous filtering material comprises a filter plasticizer and the amount of filter plasticizer in the upstream element is less than 4 weight percent of the upstream element. Example 48. 48. An aerosol generation system according to any one of Examples 40 to 47, wherein the upstream element has a withdrawal resistance of less than 25 millimeters of H2O. Example 49. 49. An aerosol generation system according to any one of Examples 40 to 48, wherein the upstream element has a length of 3 millimeters to 7 millimeters. Example 50. 50. An aerosol generating system according to any one of Examples 40 to 49, wherein the upstream element is surrounded by a wrapper. Example 51. 51. An aerosol generating system as described in Example 50, wherein the wrapper has a thickness of less than 40 microns. Example 52. 52. An aerosol generating system as described in Example 50 or 51, wherein the wrapper has a basis weight of less than 25 grams per square meter. Example 53. An aerosol-generating system according to any one of Examples 1 to 52, wherein the overall RTD of the aerosol-generating article is at least 25 millimeters HO. Example 54. 54. The aerosol-generating system of any one of Examples 1 to 53, wherein the aerosol-generating article further comprises an outer wrapper. Example 55. 55. The aerosol-generating article of Example 54, wherein the outer wrapper has a thickness of less than 65 microns. Example 56. 56. The aerosol-generating article of example 54 or 55, wherein the outer wrapper has a basis weight of less than 45 grams per square meter. Example 57. An aerosol generating system described in any of Examples 1 to 56, wherein the heating chamber comprises a pair of opposing flat surfaces configured to receive a rod of the aerosol-generating substrate therebetween, and a heater element provided on or near at least one of the pair of opposing flat surfaces. Example 58. An aerosol generation system as described in Example 57, wherein the pair of opposing flat surfaces of the heating chamber are substantially parallel to each other. Example 59. An aerosol generation system described in Example 57 or 58, wherein the average distance between a pair of opposing flat surfaces of the heating chamber is less than 5 millimeters. Example 60. An aerosol generating system described in any of Examples 57 to 59, wherein the average spacing between a pair of opposing surfaces of the heating chamber is at least 1 millimeter smaller than the maximum diameter of the rod of the aerosol-generating substrate before inserting the aerosol-generating article into the aerosol-generating device. Example 61. 61. An aerosol-generating system according to any one of Examples 57 to 60, wherein the ratio of the initial diameter of the rod of the aerosol-generating substrate to the spacing between the pair of opposing surfaces of the heating chamber is at least 1.5. Example 62. 62. An aerosol generating system according to any one of Examples 57 to 61, wherein the cross section of the heating chamber is configured such that the rod of the aerosol-generating substrate and the upstream element are compressed when the rod of the aerosol-generating substrate is inserted into the heating chamber. Example 63. 63. The aerosol-generating system of Example 62, wherein the cross-sectional area of ​​the heated chamber is smaller than the initial cross-sectional area of ​​the rod of the aerosol-generating substrate. Example 64. An aerosol generation system described in any of Examples 1 to 63, wherein the heating chamber includes a funnel-shaped portion at the open downstream end, and the funnel portion has a cross-sectional area that gradually decreases from the downstream end to the upstream end. Example 65. An aerosol generation system described in any of Examples 1 to 64, wherein the heating chamber comprises a pair of movable walls, at least one of which has a heater element on or near its inner surface, and the movable walls are adapted to be movable relative to each other between an open position and a closed position. Example 66. 66. The aerosol generating system of any one of Examples 1 to 65, wherein the heater assembly comprises an induction heating assembly.

[0282] The invention will now be further described with reference to the accompanying drawings.

[0283] 1 includes a rod of aerosol-generating substrate 12 and a downstream section 14 located downstream of the rod of aerosol-generating substrate 12. The aerosol-generating article 10 thus extends from an upstream or distal end 16, which substantially coincides with the upstream end of the rod 12, to a downstream or oral end 18, which coincides with the downstream end of the downstream section 14. The downstream section 14 comprises a hollow tubular element 20 and a mouthpiece element 50.

[0284] The aerosol-generating article 10 has an overall length of about 45 millimeters and an outer diameter of about 7.1 millimeters.

[0285] The aerosol-generating substrate rod 12 has a length of 12 millimeters and contains shredded tobacco material. The aerosol-generating substrate rod 12 contains approximately 70 milligrams of shredded tobacco material containing 13 to 16 weight percent glycerin. The bulk density of the aerosol-generating substrate rod 12 is approximately 150 milligrams per cubic centimeter. The aerosol-generating substrate rod 12 is cylindrical and has a circular cross-section with an outer diameter of 7.1 millimeters. Because of the circular cross-section, the maximum diameter of the aerosol-generating substrate rod is also 7.1 millimeters. The initial cross-sectional area of ​​the aerosol-generating substrate rod is approximately 39.5 square millimeters.

[0286] The rods 12 of aerosol-generating substrate are individually wrapped with plug wrap (not shown).

[0287] The hollow tubular element 20 is located immediately downstream of the rod 12 of the aerosol-generating substrate, and the hollow tubular element 20 is longitudinally aligned with the rod 12. The upstream end of the hollow tubular element 20 abuts the downstream end of the rod 12 of the aerosol-generating substrate.

[0288] The hollow tubular element 20 defines the hollow section of the aerosol-generating article 10. The hollow tubular element does not contribute substantially to the overall RTD of the aerosol-generating article. More specifically, the RTD of the hollow tubular element 20 is about 0 mmH2O.

[0289] 2, the hollow tubular element 20 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular element 20 defines an interior cavity 22 that extends from the upstream end of the hollow tubular element 20 all the way to the downstream end of the hollow tubular element 20. The interior cavity 22 is substantially empty, such that substantially unrestricted airflow is possible along the interior cavity 22. The hollow tubular element 20 does not substantially contribute to the overall RTD of the aerosol-generating article 10.

[0290] The hollow tubular element 20 has a length of about 21 millimeters, an outer diameter of about 7.1 millimeters, and an inner diameter of about 6.7 millimeters. The peripheral wall thickness of the hollow tubular element 20 is therefore about 0.25 millimeters.

[0291] The aerosol-generating article 10 includes a ventilation zone 30 provided at a location along the hollow tubular element 20. More specifically, the ventilation zone 30 is located approximately 16 millimeters from the downstream end 18 of the article 10. The ventilation zone 30 is located approximately 12 mm downstream from the downstream end of the aerosol-generating substrate rod 12. The ventilation zone 30 is provided approximately 9 millimeters upstream from the upstream end of the mouthpiece element 50. The ventilation zone 30 includes a circumferential array of openings or perforations surrounding the hollow tubular element 20. The perforations in the ventilation zone 30 extend through the wall of the hollow tubular element 20 to allow fluid entry from outside the article 10 into the interior cavity 22. The aerosol-generating article 10 has a ventilation level of approximately 16 percent.

[0292] The aerosol-generating article 10 further includes an upstream section 40 located upstream of the rod 12 of aerosol-generating substrate. The aerosol-generating article 10 therefore extends from a distal end 16 that is substantially coincident with the upstream end of the upstream section 40 to a mouth or downstream end 18 that is substantially coincident with the downstream end of the downstream section 14.

[0293] The upstream section 40 includes an upstream element 42 located immediately upstream of the aerosol-generating substrate rod 12 and longitudinally aligned with the rod 12. The downstream end of the upstream element 42 abuts the upstream end of the aerosol-generating substrate rod 12. The upstream element 42 is provided in the form of a solid cylindrical plug of cellulose acetate tow. The upstream element 42 has a length of approximately 5 millimeters. The outer diameter of the upstream element 42 is approximately 7.1 millimeters.

[0294] The mouthpiece element 50 extends from the downstream end of the hollow tubular element 20 to the downstream or mouth end of the aerosol-generating article 10. The mouthpiece element 50 has a length of approximately 7 millimeters. The outer diameter of the mouthpiece element 50 is approximately 7.1 millimeters. The mouthpiece element 50 comprises a low-density cellulose acetate filter segment. The RTD of the mouthpiece element 50 is approximately 8 mmH2O. The mouthpiece element 50 may be individually wrapped with plug wrap (not shown).

[0295] 1 and 2, article 10 includes an upstream wrapper 44 that surrounds upstream element 42, a rod of aerosol-generating substrate 12, and hollow tubular element 20. Ventilation zone 30 may also include a row of circumferential perforations disposed on upstream wrapper 44. The perforations in upstream wrapper 44 overlap with perforations provided on hollow tubular element 20. As a result, upstream wrapper 44 overlies the perforations of ventilation zone 30 provided on hollow tubular element 20.

[0296] The article 10 also includes a tipping wrapper 52 that surrounds the hollow tubular element 20 and the mouthpiece element 50. The tipping wrapper 52 overlies the portion of the upstream wrapper 44 that overlies the hollow tubular element 20. In this manner, the tipping wrapper 52 effectively connects the mouthpiece element 50 to the remaining components of the article 10. The width of the tipper wrapper 52 is approximately 26 mm. Additionally, the ventilation zone 30 may include a circumferential row of perforations provided on the tipping wrapper 52. The perforations in the tipping wrapper 52 overlap with the perforations provided on the hollow tubular element 20 and the upstream wrapper 44. As a result, the tipping wrapper 52 overlies the perforations of the ventilation zone 30 that are provided on the hollow tubular element 20 and the upstream wrapper 44.

[0297] Figure 3 shows an aerosol-generating device for use in combination with the aerosol-generating article 10 as shown in Figures 1 and 2. The aerosol-generating device is shown prior to insertion of the aerosol-generating article.

[0298] The aerosol generating device 100 shown in Figure 3 comprises a housing (or body) 102 extending between a mouth end 104 and a distal end (not shown). The housing 102 includes a peripheral wall 106. The peripheral wall 106 defines an elongated heating chamber 108 for receiving the aerosol-generating article 10. The heating chamber 108 is defined by a closed distal end and an open mouth end. The mouth end 104 of the heating chamber 108 is located at the mouth end of the aerosol generating device 100. The aerosol-generating article 10 is configured to be received through the mouth end 104 of the heating chamber 108 and abut the closed end of the heating chamber 108.

[0299] The heating chamber 108 has a substantially rectangular cross-section and defines a pair of opposing flat walls 109 that are substantially parallel to one another and spaced about 2 millimeters apart. In use, the aerosol-generating substrate rod 12 of the aerosol-generating article 10 is inserted between the opposing flat walls 109. Each of the opposing flat walls 109 is provided with a planar heating element (not shown) in the form of a resistive heating element. The heating chamber thus provides a heater assembly comprising a pair of opposing flat heater elements, or heater plates. In use, when the aerosol-generating substrate rod 12 is inserted between the opposing flat walls 109, the aerosol-generating substrate is heated from the top and bottom by the opposing heater elements.

[0300] The spacing between the opposing flat walls 109 of the heating chamber 108 is approximately 5 millimeters less than the diameter of the rod of aerosol-generating substrate 12 before the aerosol-generating article 10 is inserted into the aerosol-generating device 100. Thus, the rod of aerosol-generating substrate 12 is significantly compressed when inserted into the heating chamber 108, as will be described in more detail below.

[0301] An airflow channel 105 of the device is defined in a peripheral wall 106. The airflow channel 105 extends between an inlet 107 located at the mouth end of the aerosol-generating device 100 and the closed end of the heating chamber. Air may enter the aerosol-generating substrate 12 through an opening (not shown) provided in the closed end of the device cavity, ensuring fluid communication between the airflow channel 105 and the aerosol-generating substrate 12.

[0302] The aerosol-generating device 100 further includes a power supply (not shown) for supplying power to the heater element. A controller (not shown) is also provided for controlling the supply of such power to the heater element. The heater element is configured to controllably heat the aerosol-generating article 10 during use when the aerosol-generating article 10 is received within the device 100. The heater is preferably arranged to externally heat the aerosol-generating substrate 12 for optimal aerosol generation. The ventilation zone 30 is arranged to be exposed to the aerosol-generating article 10 when received within the aerosol-generating device 100.

[0303] To insert the aerosol-generating article 10 into the aerosol-generating device 100, the aerosol-generating substrate rod 12 must be compressed and flattened so that the cross-sectional dimensions of the aerosol-generating substrate rod 12 substantially match the cross-sectional dimensions of the heated chamber 108 of the aerosol-generating device. In particular, the aerosol-generating substrate rod 12, having an initial diameter of 7.1 millimeters, must be compressed so that it is flattened in one dimension to a thickness that substantially matches the spacing between the opposing flat walls 109 of the heated chamber 108 (approximately 2 millimeters). The upstream element 23 must also be compressed to the same cross-sectional dimensions.

[0304] To insert the upstream end of the rod of aerosol-generating substrate 12 into the heating chamber 108, the consumer may need to squeeze or pinch the upstream end to flatten it. Once the end of the aerosol-generating article 10 is in place within the heating chamber 108, the aerosol-generating article 10 can be pushed upstream to insert as much of the rod of aerosol-generating substrate as possible into the heating chamber 108. The remaining portion of the rod of aerosol-generating substrate 12 is compressed and flattened as the aerosol-generating article 10 is pushed inward.

[0305] When the aerosol-generating substrate rod 12 is fully received within the heating chamber 108, it has a rectangular cross-section with a height of 2 millimeters and a width of approximately 9 millimeters. This width corresponds to the final maximum diameter of the aerosol-generating substrate rod 12. Therefore, the final maximum diameter is approximately 1.25 times the initial maximum diameter. After compression of the aerosol-generating substrate rod 12, its density increases to approximately 315 milligrams per cubic centimeter. Therefore, the final density of the aerosol-generating substrate is more than twice its initial density. The cross-sectional area is reduced to approximately 18 square millimeters. Therefore, the initial cross-sectional area is more than twice the final cross-sectional area.

[0306] Compressing the aerosol-generating substrates into the rectangular shape of the rod 12 increases the contact area between the aerosol-generating substrates and the heater element and also reduces the distance heat must travel to effectively heat all of the aerosol-generating substrates within the rod. Thus, the aerosol-generating substrates can be heated very efficiently with minimal waste of tobacco material.

[0307] A funnel-shaped section of gradually decreasing cross-sectional area at the downstream end of the heating chamber 108 facilitates insertion of the rod of aerosol-generating substrate 12 into the heating chamber 108 and helps to gradually compress the rod of aerosol-generating substrate. While this is not shown in Figure 3, the use of a funnel-shaped section is shown diagrammatically in Figure 4.

[0308] FIG. 4 shows a schematic diagram of the insertion of a rod of aerosol-generating substrate 12 into a heating chamber 208 that includes a funnel-shaped section 210 at its downstream end. The downstream end of the funnel-shaped section 210 has a cross-sectional area significantly larger than that of the rod of aerosol-generating substrate, and the cross-sectional area and shape gradually change toward the upstream end of the funnel-shaped section so that the cross-sectional area and shape substantially matches the cross-sectional area of ​​the remainder of the heating chamber 208 at the upstream end of the funnel-shaped section. As mentioned above, a heating element is provided on a flat opposing wall 209 provided inside the heating chamber. For simplicity, only the rod of aerosol-generating substrate 12 is shown in FIG. 4 . The downstream section of the aerosol-generating article remains outside the heating chamber. The left side of FIG. 4 shows the aerosol-generating system before the aerosol-generating article is inserted into the aerosol-generating device, while the right side of FIG. 4 shows the aerosol-generating system after the aerosol-generating article has been inserted into the aerosol-generating device.

[0309] As shown on the left side of Figure 4, the aerosol-generating substrate rod 12 has an initial diameter and cross-sectional area significantly larger than the diameter and cross-sectional area of ​​the heating chamber 208. Therefore, the aerosol-generating substrate rod 12 must be compressed when inserted into the heating chamber 208, as described above. Once in place within the heating chamber 208, the aerosol-generating substrate rod is sandwiched between opposing flat walls 209 and has a substantially rectangular cross-section. Therefore, the aerosol-generating substrate rod is significantly flattened, increasing the density of the aerosol-generating substrate. Because the largest of the rectangular surfaces of the compressed aerosol-generating substrate rod 12 contacts the opposing flat walls, the aerosol-generating substrate rod is heated from both above and below during heating. Therefore, the aerosol-generating substrate rod is significantly flattened, increasing the density of the aerosol-generating substrate.

[0310] In other embodiments, the heating chamber may include a movable wall, as described above. The use of such a heating chamber is illustrated in FIG.

[0311] FIG. 5 shows a schematic diagram of inserting the aerosol-generating substrate rod 12 into the heating chamber 308. The heating chamber 308 includes a pair of flat movable walls 310 joined at one end and rotatable relative to each other about a hinge line 312. The movable walls 310 are rotatable about the hinge line 312 between an open position, shown on the left side of FIG. 5, and a closed position, shown on the right side of FIG. 5. In the open position, the movable walls 310 are spaced apart, allowing the aerosol-generating substrate rod 12 to be easily inserted into the space between the walls 310. To close the heating chamber, the movable walls 310 are returned to the closed position toward each other. As the movable walls 310 are pressed together, the aerosol-generating substrate rod is compressed and flattened. In the closed position of the movable walls 310, the aerosol-generating substrate rod assumes a flat shape with a substantially rectangular cross section. The flattened aerosol-generating substrate rod is sandwiched between the movable walls with its largest rectangular surface in contact with the movable walls. A heater element is provided on the surface of each movable wall, and heats the rod of the aerosol-generating substrate from both above and below during heating.

[0312] For simplicity, only the rod 12 of the aerosol-generating substrate is shown in Figure 4. The downstream section of the aerosol-generating article remains outside the heating chamber.

[0313] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are understood to be modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Accordingly, in this context, the number A is understood as A ± 10%. Within this context, the number A may be considered to include a numerical value that is within the typical standard error for measurement of the property that the number A modifies. In some instances, as used in the appended claims, the number A may deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. An aerosol generating system comprising:

1. An aerosol-generating article for generating an inhalable aerosol upon heating, the article extending from an oral end to a distal end; a rod of an aerosol-generating substrate; an aerosol-generating article comprising: a downstream section located downstream of the rod of the aerosol-generating substrate, the downstream section extending from a downstream end of the rod of the aerosol-generating substrate to the mouth end of the aerosol-generating article; An aerosol generating device, comprising: a body defining a heating chamber for removably receiving at least a portion of the rod of the aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device; a heater assembly disposed along at least a portion of the heating chamber for heating the rod of the aerosol-generating substrate when the aerosol-generating article is received within the aerosol-generating device; an aerosol generating system, wherein the rod of aerosol-generating substrate has an initial density of less than 250 milligrams per cubic centimeter prior to insertion of the aerosol-generating article into the aerosol-generating device, and the cross-section of the heating chamber of the aerosol-generating device is configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final density of at least 1.5 times its initial density.

2. 2. The aerosol-generating system of claim 1, wherein the initial density of the rods of the aerosol-generating substrate is less than 200 milligrams per cubic centimeter.

3. 3. The aerosol generating system of claim 1, wherein the final density is at least twice the initial density.

4. 4. The aerosol generating system of claim 1, wherein the final density is at least 300 milligrams per cubic centimeter.

5. 1. An aerosol generating system comprising:

1. An aerosol-generating article for generating an inhalable aerosol upon heating, the article extending from an oral end to a distal end; a rod of an aerosol-generating substrate; an aerosol-generating article comprising: a downstream section located downstream of the rod of the aerosol-generating substrate, the downstream section extending from a downstream end of the rod of the aerosol-generating substrate to the mouth end of the aerosol-generating article; An aerosol generating device, comprising: a body defining a heating chamber for removably receiving at least a portion of the rod of the aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device; a heater assembly for heating the rod of aerosol-generating substrate when the rod of aerosol-generating substrate is received within the heating chamber, the rod of aerosol-generating substrate has an initial density of less than 250 milligrams per cubic centimeter prior to insertion of the aerosol-generating article into the aerosol-generating device; an aerosol generating system, wherein the rod of aerosol-generating substrate has an initial cross-sectional area prior to insertion of the aerosol-generating article into the aerosol-generating device, and the cross-section of the heating chamber of the aerosol-generating device is configured such that, upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed to a final cross-sectional area, and the initial cross-sectional area is at least 1.5 times the final cross-sectional area.

6. 6. The aerosol generating system of claim 5, wherein the initial cross-sectional area of ​​the rod of the aerosol-generating substrate is at least 30 square millimeters.

7. 7. An aerosol-generating system according to claim 5 or 6, wherein the initial cross-sectional area of ​​the rod of the aerosol-generating substrate is at least twice the final cross-sectional area.

8. 8. The aerosol generating system of claim 5, wherein the final cross-sectional area is less than 22 square millimeters.

9. 1. An aerosol generating system comprising:

1. An aerosol-generating article for generating an inhalable aerosol upon heating, the article extending from an oral end to a distal end; a rod of an aerosol-generating substrate; an aerosol-generating article comprising: a downstream section located downstream of the rod of the aerosol-generating substrate, the downstream section extending from a downstream end of the rod of the aerosol-generating substrate to the mouth end of the aerosol-generating article; An aerosol generating device, comprising: a body defining a heating chamber for removably receiving at least a portion of the rod of the aerosol-generating substrate of the aerosol-generating article when the aerosol-generating article is inserted into the aerosol-generating device; a heater assembly for heating the rod of aerosol-generating substrate when the rod of aerosol-generating substrate is received within the heating chamber, the rod of aerosol-generating substrate has an initial density of less than 250 milligrams per cubic centimeter prior to insertion of the aerosol-generating article into the aerosol-generating device; 1. An aerosol generation system, wherein the rod of aerosol-generating substrate has an initial maximum diameter prior to insertion of the aerosol-generating article into the aerosol-generating device, and wherein a cross-section of the heating chamber of the aerosol-generating device is such that upon insertion of the rod of aerosol-generating substrate into the heating chamber, the rod of aerosol-generating substrate is compressed such that, after compression, it has a final maximum diameter that is at least 1.5 times the initial maximum diameter.

10. 10. The aerosol-generating system of claim 9, wherein the final maximum diameter of the aerosol-generating substrate is at least 8 millimeters.

11. 11. The aerosol generating system of claim 1, wherein the aerosol-generating substrate has a substantially circular cross section before the aerosol-generating article is inserted into the aerosol-generating device, and the aerosol-generating substrate has a substantially rectangular cross section after the aerosol-generating article is inserted into the aerosol-generating device.

12. 12. The aerosol generating system of claim 11, wherein after the aerosol-generating article is inserted into the aerosol-generating device, the cross-section of the aerosol-generating substrate is substantially rectangular, the width of the rectangle being at least twice the height of the rectangle.

13. 13. An aerosol generating system as described in any one of claims 1 to 12, wherein the resistance to withdrawal (RTD) of the aerosol-generating article after insertion of the aerosol-generating article into the aerosol generating device does not exceed the RTD of the aerosol-generating article before insertion of the aerosol-generating article into the aerosol generating device by more than 10 percent.

14. 14. An aerosol generation system as described in any one of claims 1 to 13, wherein the heating chamber comprises a pair of opposing flat surfaces configured to receive the rod of the aerosol-generating substrate therebetween, and a heater element provided on or near at least one of the pair of opposing flat surfaces.

15. 15. An aerosol generation system as described in any one of claims 1 to 14, wherein the heating chamber further comprises a funnel-shaped portion at the downstream end, the cross-sectional area of ​​the funnel-shaped portion gradually decreasing from the downstream end to the upstream end.

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