Plug element for use in an aerosol-generating article comprising a paper material, an aerosol-generating article comprising the plug element, and a method of manufacturing

Abstract

A plug element for use in an aerosol-generating article comprises a cellulosic filtration material. The cellulosic filtration material comprises a sheet of glassine paper. The sheet comprises a first surface comprising a first three-dimensionally patterned surface, and an additive coating at least partly impregnated into the sheet. The plug element is obtainable by a method comprising: providing cellulosic filtration material comprising a sheet of glassine paper; treating the sheet to form a first three-dimensionally patterned surface on a first surface of the sheet; and at least partly impregnating the first surface with an additive coating.

Description

[0001] P408336WQ - 14 January 2026 FTR4090 / PCT .. 1 ..

[0002] PLUG ELEMENT FOR USE IN AN AEROSOL-GENERATING ARTICLE COMPRISING A PAPER MATERIAL, AN AEROSOL-GENERATING ARTICLE COMPRISING THE PLUG ELEMENT,

[0003] AND A METHOD OF MANUFACTURING

[0004] TECHNICAL FIELD

[0005] The present invention relates to a plug element for use in an aerosol-generating article, wherein the plug element is formed from a biodegradable filtration material. In particular, the present invention relates to a plug element which, in an aerosol-generating article, is located downstream of, and in axial alignment with, an aerosol-generating substrate, the plug element comprising formed from sheet of paper material.

[0006] Further, the present invention relates to a method of manufacturing such a plug element for use in an aerosol-generating article and to plug elements for use in an aerosol-generating article obtainable by such a method.

[0007] BACKGROUND

[0008] Conventional aerosol-generating articles, such as filter cigarettes, typically comprise a cylindrical rod of tobacco cut filler surrounded by a paper wrapper and a cylindrical filter axially aligned, most often in an abutting end-to-end relationship, with the wrapped tobacco rod. The cylindrical filter typically comprises one or more plug elements of a fibrous filtration material, such as cellulose acetate tow, circumscribed by a paper plug wrap. Conventionally, the wrapped tobacco rod and the filter are joined by a band of tipping wrapper, normally formed of an opaque paper material that circumscribes the entire length of the filter and an adjacent portion of the wrapped tobacco rod. In known filter cigarettes, the filter is typically adapted for the removal of particulate and gaseous components of the mainstream smoke.

[0009] A number of aerosol-generating articles in which tobacco is heated rather than combusted have also been proposed in the art. In heated aerosol-generating articles, an aerosol is generated by heating an aerosol-generating substrate, such as tobacco. Known heated aerosol-generating articles include, for example, smoking articles in which an aerosol is generated by electrical heating or by the transfer of heat from a combustible fuel element or heat source to an aerosol-generating substrate. During smoking, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and entrained in air drawn through the smoking article. As the released compounds cool they condense to form an aerosol that is inhaled by the consumer.

[0010] Many known heated aerosol-generating articles comprise one or more elements formed of a fibrous filtration material and arranged downstream of the aerosol-generating substrate. For example, aerosolgenerating articles have been proposed that comprise a support element arranged immediately downstream of the aerosol-generating substrate, wherein the support element may be configured to impart structural strength to the aerosol-generating article and to resist downstream movement of the aerosolgenerating substrate when the aerosol-generating substrate cooperates with the aerosol-generating device during use. Further, aerosol-generating articles have been described that comprise an aerosol-cooling element arranged downstream of the aerosol-generating substrate and configured to lower the temperature of an aerosol produced upon heating the aerosol-generating substrate prior to the aerosol reaching the mouth end of the aerosol-generating article. WO 2013 / 120565 A2, for example, describes an aerosolgenerating article comprising an aerosol-cooling element arranged downstream of a rod of aerosol-P408336WQ - 14 January 2026 FTR4090 / PCT - 2 - generating substrate. The aerosol-cooling element may be formed from a sheet material, such as for example a sheet of polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), a metallic foil (like aluminium foil), paper or cardboard.

[0011] After an aerosol-generating article has been smoked and discarded, it would generally be desirable for its components - and particularly for any elements formed of fibrous filtration material - to break down as quickly as possible. However, cellulose acetate, the fibrous filtration material most ordinarily used in aerosol-generating articles, is not biodegradable, and can persist in the environment for years. As a result, used cigarette filters formed from cellulose acetate have a tendency to accumulate in the environment, and are among the most commonly retrieved plastic items in beach clean-up activities. Therefore, it would be desirable to provide a more sustainable alternative to cellulose acetate for producing aerosol-generating article components and in particular, filter or mouthpiece components.

[0012] To tackle the environmental impact caused by post-consumption waste of articles containing non-biodegradable plastic, discarded directly into the environment, certain jurisdictions are introducing legislations banning single-use plastic products (SUPs). The term SUPs denotes products made wholly or partly from plastic and that are typically intended to be used just once or for a short period of time before being disposed of. Accordingly, it would be generally desirable to replace single-use plastics in aerosolgenerating articles with natural, biodegradable alternatives.

[0013] A wide variety of alternative materials have in fact already been proposed for use as filtration materials for aerosol-generating articles. However, in many cases, such alternative filtration materials have been found to be unable to provide an acceptable filtration efficiency and smoking experience for the consumer.

[0014] For example, filters made of cellulose pulp or paper material have been known for almost a century, as evidenced by GB 433048 A. Several processes for manufacturing paper filters have been disclosed over the years, such as the ones described in US 3238852 A. However, consumers have often reported that paper filters have an undesirable effect on the taste of the smoke or aerosol. This so-called “paper taste” has been described as being associated with a harsher, drier sensation compared to that provided by a known smoking article comprising a filter formed of cellulose acetate.

[0015] Furthermore, filters made of processed paper materials, such as glassine paper, parchment paper or natural greaseproof paper have physical characteristics that limit or prevent incorporation of additive coatings to the filters so as to modify their behaviour. For example, glassine paper includes an inherently smooth and compressed fibrous surface, resulting in low porosity and strong resistance to penetration, particularly by liquids. Known approaches to mitigating the limitations brought about by such characteristics, such as spraying or dipping processed paper materials are inefficient and typically lead to poor distribution or stability of the additive coating layer.

[0016] In other cases, such alternative filtration materials have been found to be lacking from a firmness and processability viewpoint. Furthermore, in many cases dispersible and degradable materials have been found to be unsuitable for use in the existing manufacturing processes, and would require too significant a modification of the existing methods and equipment to make their use commercially feasible.

[0017] It is an aim of certain examples of the present invention to solve, mitigate or obviate, at least partly, at least one of the problems and / or disadvantages associated with the prior art.P408336WQ - 14 January 2026 FTR4090 / PCT - 3 - Thus, it would be desirable to provide a plug element for use in an aerosol-generating article, the plug element being at least partially formed of a filtration material having increased biodegradability, but which provides levels of firmness that are comparable to those of a plug of cellulose acetate tow.

[0018] Furthermore, it would be desirable to provide a plug element formed of a biodegradable filtration material that, when used in an aerosol-generating article, provides an acceptable appearance and feeling to the consumer, for example in terms of density, firmness and resistance to draw (RTD).

[0019] In addition, it would be desirable to provide a plug element formed of a biodegradable filtration material that, when used in an aerosol-generating article, gives an acceptable sensory experience to the consumer. In general, it would be desirable for the plug element to have very little or no impact on the taste perceived by the consumer during use of the aerosol-generating article, and for the plug element to generally not adversely impact the smoking experience. In particular, it would be desirable to provide such a plug element that, when used in an aerosol-generating article, is less likely to cause the aerosolgenerating article to generate a smoke or aerosol associated with a harsh, dry sensation for the consumer. For example, it would be desirable to provide such a plug element that comprises a paper material that has reduced or no “paper taste”.

[0020] That is, without prejudice for the inherent taste variability associated with different types of aerosolgenerating substrates, it would be desirable to provide such an aerosol-generating article comprising a plug element formed of a biodegradable filtration material that provides a smoke or aerosol having a taste profile comparable with that of existing, cellulose acetate filtered aerosol-generating articles.

[0021] In view of use of the plug element in an aerosol-generating article wherein an aerosol-generating substrate is heated ratherthan combusted, it would also be desirable to provide such a plug element formed of a biodegradable filtration material that has a comparatively low filtration efficiency.

[0022] It would also be desirable to provide a plug element comprising a processed paper material that overcomes its inherent resistance to liquid penetration. In particular, it would be useful to provide a processed paper material, such as glassine, that has useful physical characteristics, such as rigidity and biodegradability, while enabling controlled uptake and retention of additive coatings. It would be desirable to apply additive coatings to processed paper materials in a more efficient process.

[0023] In addition, it would be desirable to provide such a plug element and an aerosol-generating article comprising the plug element that can be readily manufactured using existing high speed techniques and apparatus requiring only minimal modifications.

[0024] BRIEF SUMMARY

[0025] The invention is set out in the appended claims.

[0026] The present disclosure relates to a plug element for use in an aerosol-generating article.

[0027] The plug element may comprise a cellulosic filtration material.

[0028] The cellulosic filtration material may comprise a sheet of paper material.

[0029] The sheet of paper material may be a sheet of a processed paper material. For example, processed paper material may be glassine paper, parchment paper or natural greaseproof paper.

[0030] The sheet of paper material may be embossed or debossed.

[0031] An RTD of the plug element may be at least 0.8 millimetres WG per unit length.

[0032] The plug element may be included in an aerosol-generating article comprising a rod of aerosolgenerating substrate and a downstream section located downstream of the rod of aerosol-generatingP408336WQ - 14 January 2026 FTR4090 / PCT - 4 - substrate. The downstream section may comprise a downstream element in axial alignment with the rod of aerosol-generating substrate, the downstream element comprising the plug element.

[0033] The plug element may be included in an aerosol-generating article comprising a rod of aerosolgenerating substrate and an upstream section located upstream of the rod of aerosol-generating substrate. The upstream section may comprise an upstream element in axial alignment with the rod of aerosolgenerating substrate, the upstream element comprising the plug element.

[0034] According to a first aspect of the present invention, there is provided a plug element for use in an aerosol-generating article. The plug element comprises a cellulosic filtration material comprising a sheet of paper material. The sheet of paper material is embossed or debossed. An RTD of the plug element is at least 0.8 millimetres WG per unit length.

[0035] According to a second aspect of the present invention, there is provided an aerosol-generating article. The aerosol-generating article comprises a rod of aerosol-generating substrate, and a downstream section located downstream of the rod of aerosol-generating substrate. The downstream section comprises a downstream element in axial alignment with the rod of aerosol-generating substrate. The downstream element comprises a plug element according to the first aspect of the present invention.

[0036] The present disclosure further relates to a method of manufacturing a plug element for use in an aerosol-generating article.

[0037] The method may comprise a first step of providing a sheet of paper material.

[0038] The method may comprise a second step of embossing or debossing the sheet of paper material to form an embossed or debossed sheet of paper material.

[0039] The method may comprise a third step of gathering the embossed or debossed sheet of paper material to form a continuous rod of cellulosic filtration material.

[0040] The method may comprise a fourth step of cutting the continuous rod of cellulosic filtration material into a plurality of plug elements.

[0041] The third step of gathering the embossed or debossed sheet of paper material may be carried out immediately after the second step of embossing or debossing the sheet of paper material.

[0042] The present disclosure additionally relates to a plug element for use in an aerosol-generating article, the plug element obtainable by such a method of manufacturing.

[0043] According to a third aspect of the present invention, there is provided a method of manufacturing a plug element for use in an aerosol-generating article, the method comprising: providing a continuous sheet of paper material; embossing or debossing the continuous sheet of paper material to form a continuous embossed or debossed sheet of paper material; gathering the continuous embossed or debossed sheet of paper material to form a continuous rod of cellulosic filtration material; cutting the continuous rod of cellulosic filtration material into a plurality of plug elements; wherein the step of gathering the embossed or debossed sheet of paper material is carried out immediately after the step of embossing or debossing the continuous sheet of paper material.

[0044] According to a fourth aspect of the present invention, there is provided a plug element for use in an aerosol-generating article, the plug element comprising a cellulosic filtration material comprising a sheet of paper material, wherein the plug element is obtainable by a method comprising the steps of: providing a continuous sheet of paper material; embossing or debossing the continuous sheet of paper material to form a continuous embossed or debossed sheet of paper material; gathering the continuous embossed or debossed sheet of paper material to form a continuous rod of cellulosic filtration material; cutting theP408336WQ - 14 January 2026 FTR4090 / PCT - 5 - continuous rod of cellulosic filtration material into a plurality of plug elements; wherein the step of gathering the embossed or debossed sheet of paper material is carried out immediately after the step of embossing or debossing the continuous sheet of paper material.

[0045] According to another aspect of the present invention, there is provided a plug element of an of an aerosol-generating article, the plug element comprising:

[0046] a cellulosic filtration material comprising a sheet of glassine paper,

[0047] wherein the sheet comprises:

[0048] a first surface comprising a first three-dimensionally patterned surface, and an additive coating at least partly impregnated into the sheet.

[0049] According to a further aspect of the present invention, there is provided a method of manufacturing a plug element for an aerosol-generating article, the method comprising:

[0050] providing cellulosic filtration material comprising a sheet of glassine paper;

[0051] treating the sheet to form a first three-dimensionally patterned surface on a first surface of the sheet; and

[0052] at least partly impregnating the first surface with an additive coating.

[0053] According to yet another aspect of the present invention, there is provided an aerosol-generating article comprising:

[0054] a rod of aerosol-generating substrate;

[0055] a downstream section located downstream of the rod of aerosol-generating substrate; wherein the downstream section comprises a downstream element in axial alignment with the rod of aerosol-generating substrate,

[0056] wherein the downstream element comprises a plug element having a cellulosic filtration material comprising a sheet of glassine paper; and

[0057] wherein the sheet comprises: a first surface comprising a first three-dimensionally patterned surface, and an additive coating at least partly impregnated into the sheet.

[0058] As used herein with reference to the invention, the term “aerosol-generating article” is used to describe an article comprising an aerosol-generating substrate that is heated to generate an inhalable aerosol for delivery to a user.

[0059] As used herein with reference to the invention, the term “aerosol-generating substrate” is used to describe a substrate comprising aerosol-generating material that is capable of releasing upon heating volatile compounds that can generate an aerosol.

[0060] As used herein with reference to the invention, the term “aerosol” is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. The aerosol may be visible or invisible. The aerosol may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles, or liquid droplets, or a combination of solid particles and liquid droplets.

[0061] As used herein with reference to the invention, the term “aerosol-generating device” is used to describe a device that interacts with the aerosol-generating substrate of the aerosol-generating article to generate an aerosol.P408336WQ - 14 January 2026 FTR4090 / PCT - 6 - Aerosol-generating articles according to the invention have a proximal end through which, in use, an aerosol exits the aerosol-generating article for delivery to a user. The proximal end of the aerosolgenerating article may also be referred to as the downstream end or the mouth end of the aerosolgenerating article. In use, a user draws directly or indirectly on the proximal end of the aerosol-generating article in order to inhale an aerosol generated by the aerosol-generating article.

[0062] Aerosol-generating articles according to the invention have a distal end. The distal end is opposite the proximal end. The distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

[0063] Components of aerosol-generating articles according to the invention may be described as being upstream or downstream of one another based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

[0064] As used herein with reference to the invention, the term “longitudinal” is used to describe the direction between the upstream end and the downstream end of the aerosol-generating article. During use, air is drawn through the aerosol-generating article in the longitudinal direction.

[0065] As used herein with reference to the invention, the term “length” is used to describe the maximum dimension of the aerosol-generating article or a component of the aerosol-generating article in the longitudinal direction.

[0066] As used herein with reference to the invention, the term “transverse” is used to describe the direction perpendicular to the longitudinal direction. Unless otherwise stated, references to the “crosssection” of the aerosol-generating article or a component of the aerosol-generating article refer to the transverse cross-section.

[0067] As used herein with reference to the invention, the term “width” denotes the maximum dimension of the aerosol-generating article or a component of the aerosol-generating article in a transverse direction. Where the aerosol-generating article has a substantially circular cross-section, the width of the aerosolgenerating article corresponds to the diameter of the aerosol-generating article. Where a component of the aerosol-generating article has a substantially circular cross-section, the width of the component of the aerosol-generating article corresponds to the diameter of the component of the aerosol-generating article.

[0068] As used herein with reference to the invention, the term “rod” is used to denote a generally cylindrical element having a substantially circular, oval or elliptical cross-section.

[0069] As used herein with reference to the invention, the terms “embossing” and “debossing” are used with reference to processes by which features are transferred from a tool (for example, a roller or a die) onto a solid substrate. Embossing results into features that are raised up compared with the surrounding portions of the solid substrate. Debossing results into features that are stamped down or recessed into the surrounding portions of the solid substrate.

[0070] An embossing process requires the use of a pair of rollers or dies, one comprising a positive projection of a structure to emboss, extending from a mean surface of the tool, and one comprising a negative projection of a structure to emboss, complementary to the positive projection of the other roller or die, and recessed into the mean surface of the tool. Because the negative projection fits into the positive projection, when a solid substrate (for example, a sheet of paper) is pressed between the two tools, the positive projection forces portions of the solid substrate into the negative projection and creates the embossed features. The term “embossing roller” is used to denote a tool having cylindrical symmetry and profiled with a positive projection or a negative projection on its lateral surface.P408336WQ - 14 January 2026 FTR4090 / PCT - 7 - When a sheet of paper material is inserted between the two embossing tools, such as for example a pair of embossing rollers, a specific level of pressure is applied so that portions of the sheet of paper material are pushed into the negative projection and the fibre structure of the paper material is modified by at least one of the following effects: breaking of paper fibres, compressing of paper fibres, densifying of paper fibres.

[0071] As used herein with reference to the invention, the term "hollow tubular element" is used to denote a generally cylindrical element having a lumen along a longitudinal axis thereof. The tubular portion may have a substantially circular, oval or elliptical cross-section. The lumen may have a substantially circular, oval or elliptical cross-section. In particular, the term "hollow tubular element" is used to denote an element defining at least one airflow conduit establishing an uninterrupted fluid communication between an upstream end of the hollow tubular element and a downstream end of the tubular element.

[0072] Unless otherwise specified, the resistance to draw (RTD) of a component or an aerosol-generating article in accordance with the invention is measured in accordance with ISO 6565-2015. The RTD refers the pressure required to force air through the full length of a component. The terms “pressure drop” or “draw resistance” of a component or article may also refer to the “resistance to draw”. Such terms generally refer to the measurements in accordance with ISO 6565-2015 and are normally carried out at a volumetric flow rate of about 17.5 millilitres per second at the output ordownstream end of the measured component, at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr) and a relative humidity of about 60%.

[0073] The expression “resistance to draw (RTD) per unit length” of a particular component (or element) of the aerosol-generating article, such as the upstream element, the aerosol-generating element, and so forth, can be calculated by dividing the measured resistance to draw of the component by the total axial length of the component. The RTD per unit length refers to the pressure required to force air through a unit length of a component. Throughout the present disclosure, a unit length refers to a length of 1 millimetre. Accordingly, in order to derive the RTD per unit length of a particular component, a specimen of a particular length, 15 millimetres for example, of the component can be used in measurement. The RTD of such a specimen is measured in accordance with ISO 6565-2015. If, for example, the measured RTD is about 15 millimetres H2O, then the RTD per unit length of the component is about 1 millimetre H2O per millimetre. The RTD per unit length of the component is generally dependent on the structural properties of the material used for the component as well as the cross-sectional geometry or profile of the component, amongst other factors.

[0074] The aerosol stream generated during use of an aerosol-generating article is a complex mixture of chemicals, including semi-solid particles dispersed in a fluid matrix of vapours and permanent gases. As used herein with reference to the invention, the term "filtration efficiency" is used to describe the ability of an element comprising a filtration material to capture particulate matter contained in such aerosol stream. In practice, the term “filtration efficiency” denotes the fraction of the overall dry particulate matter carried in the aerosol stream that is retained within the element comprising filtration material during use.

[0075] The plug element of the downstream element of an aerosol-generating article in accordance with the present invention is air-permeable. As used herein, the term “air-permeable” is used to describe an entity which allows air to pass through it. The term “air-permeable” also encompasses a volume characteristic of a suitable material, either in relation to all or part of its volume; for example, a material having a porosity in all or part of the volume of the material.P408336WQ - 14 January 2026 FTR4090 / PCT - 8 - In more detail, the term “air-permeable”, as used herein with reference to the plug element of an aerosol-generating article according to the present invention, denotes a plug element that is not blocked, plugged or sealed in a way to block air from passing through the air-permeable plug element.

[0076] The air-permeable plug element may be configured so as to enable flow along a desired airflow direction. For example, an air-permeable plug element may be configured so as to enable flow from a first end of the air-permeable plug element to a second end of the air-permeable plug element longitudinally opposite the first end of the air-permeable plug element.

[0077] To enable flow along a desired airflow direction, the air-permeable plug element may comprise one or more airflow channels extending through the air-permeable plug element. For example, the air-permeable plug element may comprise one or more airflow channels extending from a first end of the air-permeable plug element to a second end of the air-permeable plug element opposite the first end of the air-permeable plug element.

[0078] The one or more airflow channels of the air-permeable plug element may be arranged within the air-permeable body portion in regular and orderly fashion. For example, the air-permeable plug element may define a plurality of substantially longitudinal airflow channels extending parallel to each other.

[0079] The term “porosity” of an air-permeable body generally denotes the ratio of the volume of the accessible pores and voids to the bulk volume occupied by the body. The term “cross-sectional porosity” refers to the fraction of void space in a cross-sectional area of an air-permeable body, and particularly in a cross-sectional of a porous body, such as for example a cross-section of an air-permeable plug element of an aerosol-generating article in accordance with the present invention.

[0080] The cross-sectional porosity is the area fraction of void space of the transverse cross-sectional area of the air-permeable plug element. The transverse cross-sectional area of the air-permeable body portion is the area of the air-permeable plug element in the plane that is perpendicular to a desired airflow direction. In particular, with reference to an air-permeable plug element extending along a longitudinal axis, the transverse cross-sectional area of the air-permeable plug element may be the area of the air-permeable plug element in the plane that is perpendicular to the longitudinal axis of the air-permeable plug element.

[0081] The plug element will typically be substantially cylindrical, and so a transverse cross-sectional of the plug element will be substantially circular. However, more generally it will be possible to identify a longitudinal axis of the plug element and a transverse cross-section of the plug element will be in a plane substantially perpendicular to said longitudinal axis.

[0082] For example, the transverse cross-sectional porosity value may be determined using a digital imaging process. A digital image of a transverse cross-section of the plug element may be obtained, and a threshold may be applied to differentiate pixels that represent solid material from pixels that represent void. A void fraction of the entire cross-section may then be easily obtained. For example, with reference to a plug element of an aerosol-generating article in accordance with the present invention, the characteristics of which will be described in more detail below, a suitable image of a transverse crosssection of the plug element can be obtained by photographing the transverse cross-section of the plug element using a digital camera or by scanning the transverse cross-section of the plug element using a scanner. Equally, a photograph may be taken using a conventional camera and the image produced may then be scanned and transformed into a digital image.

[0083] For a plug element formed from a sheet, which is gathered or otherwise processed to be formed into rod-shape, the theoretical transverse cross-sectional porosity of the plug element may also beP408336WQ - 14 January 2026 FTR4090 / PCT - 9 - calculated based on geometric parameters of the sheet. In more detail, for a sheet having a thickness (t) and a width (w) the cross-sectional area presented by an edge of the sheet material is given by the width multiplied by the thickness. For example, in a specific embodiment of a sheet having a thickness of 50 micrometres (± 2 micrometres) and a width of 230 millimetres, the cross-sectional area is approximately 1.15 x 10-5m2(this may be denoted the first area). The sheet may be gathered to form a rod having a diameter (d). The inner area of the rod is given by the formula IT (d / 2)2. Assuming a diameter of the rod of 6.9 millimetres, the inner area of the rod is 3.78 x 10-5m2(this may be denoted the second area). The ratio of the first and second area based on the above examples is approximately 0.304. This ratio is multiplied by 100 and the quotient is subtracted from 100% to arrive at the porosity, which is approximately 70% for the specific figures given here.

[0084] Clearly, the thickness and width of a sheet material may be varied. Likewise, the inner diameter of a rod may be varied. It will now be obvious to one of ordinary skill in the art that with a known thickness and width of a material, in addition to the diameter of the rod, the theoretical porosity can be calculated in the above manner. Accordingly, where a sheet of material has a known thickness and length, and is embossed and gathered along the length, the space filled by the material can be determined. The unfilled space may be calculated, for example, by taking the inner diameter of the rod. The porosity or unfilled space within the rod can then be calculated as a percentage of the total area of space within the rod from these calculations.

[0085] As used herein with reference to the invention, the term "specific surface area" is used to denote the total surface area of a solid material per unit of mass. Specific surface area is generally dependent on the size of the particles forming a solid material, as well as on the structure and porosity, pore size distribution, of the solid material.

[0086] As described briefly above, a plug element for use in an aerosol-generating article according to the present invention comprises a cellulosic filtration material comprising a sheet of paper material.

[0087] For the purposes of the invention, the term “paper material” generally denotes a web of cellulosic fibres in sheet form. As used herein with reference to the invention, the term “sheet” is used to describe a laminar element having a width and a length substantially greater than a thickness thereof. The sheet may have a thickness ranging from 0.03 to 2 millimetres and a basis weight of from 10 grams per square metre to 200 grams per square metre. The term “paper” is typically used to denote one such web of cellulosic fibres in sheet form, wherein the sheet has a thickness ranging from 0.03 to 0.20 millimetres.

[0088] To form the web, an aqueous slurry of pulp fibres is drained through a sieve-like screen, so that a mat of randomly interwoven fibres is laid down. Water is further removed from this mat by pressing, optionally assisted by suction or vacuum, or by heating, or both. Once the drying process is complete, a generally flat and uniform sheet of paper material is obtained.

[0089] The term “pulp” is used to denote a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops, waste paper, or rags. Lignocellulose is composed primarily of cellulose, hemicellulose and lignin.

[0090] The term “cellulose” denotes an organic compound with the formula (CeHioOsjn. A polysaccharide consisting of a linear chain of several hundreds to many thousands of D-glucose units joined by a glycosidic-bond, cellulose is a structural component of the primary cell wall of green plants and many algae. Cellulose, or cellulosic materials, include a natural cellulose material and / or a regenerated cellulose material, such as viscose, lyocell or the like. In this respect, cellulose acetate is a modified cellulose material, rather thanP408336WQ - 14 January 2026 FTR4090 / PCT - 10 - a cellulose material, because a substantial proportion of the hydroxyl groups of the cellulose chain have been substituted by acetyl groups. Regenerated cellulose material retains its hydroxyl groups intact despite the cellulose being treated to enable it to be extruded into new filaments.

[0091] The term “hemicellulose” identifies a groups of polysaccharides typically present with cellulose in almost all terrestrial plant cell walls. The hemicellulose polysaccharides are shorter than cellulose and typically branched. From a chemical viewpoint, while cellulose is derived exclusively from glucose, hemicellulose polysaccharides include both five-carbon sugars (xylose and arabinose) and six-carbon sugars (mannose and galactose on top of glucose). Additionally, acidified forms of sugars - such as glucuronic acid and galacturonic acid - may be found in hemicellulose.

[0092] The term “lignin” identifies a group of highly heterogeneous polymers derived from a few Precursor lignols. Its heterogeneity arises from the diversity and variable degree of crosslinking between these lignols. For example, the relative amounts of the precursor lignols generally varies depending on the plant source. The lignin polymers typically form key structural materials in the support tissues of plant, and especially in the cell walls of wood and bark, and are also found in red algae. Lignin fills gaps in the cell walls between cellulose, hemicellulose and pectin components, lending rigidity by virtue of the cross-linking between the lignol molecules.

[0093] Lignin is understood to hinder the formation of hydrogen bonds between cellulose fibres. Therefore, some pulping processes are designed to remove as much lignin as possible, as this is understood to provide stronger paper by facilitating inter-fibre bonding. Other pulping processes aim instead at separating the fibres. Pulp intended for use in fine papers typically undergoes a papermaking process aiming at both removing the lignin and separating the fibres.

[0094] However, irrespective of the specific pulping process used, the lignin gets more resistant to removal as the pulping proceeds, while the cellulose fibres become more vulnerable to the chemicals used or to the mechanical pulping or both. Therefore, at the end of the papermaking process, some lignin is ordinarily present in all paper materials, as the complete removal of lignin would in all likelihood be accompanied by excessive cellulose loss or by some less than desirable degradation of the mechanical properties of the cellulose fibres.

[0095] The present invention provides an improved plug element for use in an aerosol-generating article, the plug element being formed from an embossed or debossed sheet of paper material. In particular, as will be discussed in more detail below, a plug element for use in an aerosol-generating article according to the present invention is preferably formed by gathering the embossed or debossed sheet of paper material immediately after the sheet of paper material has been embossed or debossed. That is, the embossing or debossing of the sheet and the gathering of the embossed or debossed sheet are carried out in rapid succession at the same manufacturing location, preferably at two successive stations of a same manufacturing apparatus, without the embossed or debossed sheet being stored (for example having been wound into a roll) prior to being gathered.

[0096] The inventors have found that, compared to other types of textured webs or sheets of paper material - such as for example crimped sheets - an embossed or debossed sheet of paper material can be more easily gathered into a rod-shaped element. As used herein, the term “crimped sheet” is intended to be synonymous with the term “creped sheet” and denotes a sheet having a plurality of substantially parallel ridges or corrugations.P408336WQ - 14 January 2026 FTR4090 / PCT - 11 - Furthermore, the inventors have observed that, compared with rod-shaped elements obtained by crimping or otherwise texturing a sheet of paper material, rod-shaped elements obtained by gathering an embossed or debossed sheet of paper material display improved firmness and shape stability.

[0097] Without wishing to be bound by theory, it is understood that, when a sheet of paper material undergoes embossing or debossing, the fibre structure of the paper material is modified in that at least some of the fibres are broken or compressed or densified or a combination thereof, and that this results into a modified folding behaviour of the embossed or debossed sheet of paper material, compared with the sheet in a non-embossed or non-debossed state. Furthermore, as a result of the alteration undergone by the fibre structure of the paper material, the embossed or debossed sheet of paper material is more likely to maintain a substantially unchanged shape overtime.

[0098] The inventors have observed that, because a more consistent gathering of the sheet of paper material is thus facilitated, it may advantageously possible to more finely control the cross-sectional porosity of a plug element formed from an embossed or debossed sheet of paper material, and this may in turn favour a finer and more consistent control over the resistance to draw (RTD) of the plug element. In particular, the inventors have noticed a significant reduction in the coefficient of variation of the RTD of plug elements formed from an embossed or debossed sheet of paper material compared with the RTD of plug elements formed from a crimped sheet of paper material.

[0099] Plug elements obtained by gathering an embossed or debossed sheet of paper material in accordance with the invention may also have an improved visual impact compared with similar plug elements formed by gathering a crimped sheet of paper material.

[0100] On top of that, because an embossed or debossed sheet of paper material may be more consistently folded compared with a crimped sheet of paper material, it may advantageously be possible to achieve similar values of RTD using less paper material, the other geometric parameters (for example, length and diameter of the plug element) being the same.

[0101] In particular, the inventors have observed that values of RTD in line with ones determined for plug elements formed from a crimped sheet of paper material may advantageously be obtained with plug elements formed from an embossed or debossed sheet of paper material having a comparatively lower width. This may further simplify the manufacturing process, because continuous rods formed from sheets of paper material having a lower width tend to be easier to cut into individual plug elements.

[0102] In particular, the inventors have observed that plug elements can be produced with embossed or debossed sheets of paper materials of reduced width compared to plug elements formed from a crimped sheet of paper material. This may further simplify the manufacturing process, because continuous rods formed from sheets of paper material having a lower width tend to be easier to cut into individual plug elements.

[0103] Additionally, there may be other benefits from a manufacturing viewpoint because the embossing or debossing process is more gentle than the crimping process, and so the generation of paper dust may be considerably reduced if not eliminated altogether.

[0104] In certain embodiments, which will be described in more detail below, the application of selected additive coatings to the sheet of paper material has advantageously been found to improve the filtration properties of the plug element, particularly with reference to the ability of the plug element to reduce certain undesirable compounds from the mainstream smoke or aerosol, compared to the use of non-treated paper materials. For example, the composition of the additive coating can advantageously be modified to optimiseP408336WQ - 14 January 2026 FTR4090 / PCT - 12 - the filtration efficiency of the plug element, such that it can achieve a similar reduction in phenols and other undesirable compounds as a plug made of conventional cellulose acetate tow.

[0105] As mentioned previously, in a plug element for use in an aerosol-generating article according to the present invention the embossed or debossed paper material is typically in the form of a sheet, which is gathered or otherwise processed to be formed into rod-shape. As used herein with reference to the invention, the term “gathered” denotes that a sheet is compressed or constricted substantially transversely relative to a longitudinal axis of the plug element.

[0106] Alternatively, the web or sheet of embossed or debossed paper material may be wound to form a substantially cylindrical hollow tubular element. By varying the number of turns or convolutions, one may adjust the thickness of the hollow tubular element.

[0107] Gathering or winding the sheet of embossed or debossed paper material to form the plug element has the benefit that by adjusting the number of convolutions or how tight the sheet is gathered it is possible, to an extent, to adjust the resistance to mechanical deformation of the plug element, such that in the aerosol-generating article the plug element can withstand being grasped by the consumer during smoking.

[0108] The plug element may comprise a single sheet of embossed or debossed paper material that is gathered or otherwise processed to be formed into rod shape. Alternatively, the plug element may comprise two or more sheets of embossed or debossed paper material that are gathered or otherwise processed together to be formed into rod shape. For example, two or more sheets of embossed or debossed paper material may be laid on top of each other and gathered or otherwise processed at once to form the plug element. Two or more sheets of embossed or debossed paper material may also be gathered or otherwise processed independently, in parallel to each other, and then combined to form the plug element.

[0109] Compared with other plug elements conventionally used in aerosol-generating articles, plug elements according to the present invention are advantageously formed of more sustainable materials, containing a reduced or zero level of single use plastics. In particular, as they are formed from a sheet of paper material, in place of other more conventional materials, such as cellulose acetate fibres, plug elements according to the present invention may significantly improve the overall biodegradability of the aerosol-generating articles in which they are used. In fact, using a paper material, which comprises randomly oriented cellulose fibres, advantageously facilitates degradation of the plug element. This is because the randomly oriented fibres can more easily disperse after the plug element has been discarded, particularly when compared with the substantially continuous filaments of traditional cellulose acetate tow filters. Increased dispersion of the fibres increases the exposure of the individual fibres to the environment, thus increasing the rate at which the plug element degrades.

[0110] An RTD of a plug element in accordance with the present invention is at least 0.8 millimetres WG per unit length.

[0111] Preferably, an RTD of a plug element in accordance with the present invention is at least 0.9 millimetres WG per unit length. More preferably, an RTD of a plug element in accordance with the present invention is at least 1 millimetre WG per unit length. Even more preferably, an RTD of a plug element in accordance with the present invention is at least 1 .2 millimetres WG per unit length.

[0112] In certain preferred embodiments, an RTD of a plug element in accordance with the present invention is at least 1.5 millimetres WG per unit length, more preferably at least 1.75 millimetres WG per unit length, even more preferably at least 2.0 millimetres WG per unit length.P408336WQ - 14 January 2026 FTR4090 / PCT - 13 - An RTD of a plug element in accordance with the present invention is preferably less than or equal to 3.5 millimetres WG per unit length, more preferably less than or equal to 3.25 millimetres WG per unit length, even more preferably less than or equal to 3 millimetres WG per unit length.

[0113] For example, an RTD of a plug element in accordance with the present invention may be from 0.8 millimetres WG per unit length to 3.5 millimetres WG per unit length, preferably from 0.8 millimetres WG per unit length to 3.25 millimetres WG per unit length, more preferably from 0.8 millimetres WG per unit length to 3 millimetres WG per unit length.

[0114] For example, an RTD of a plug element in accordance with the present invention may be from 0.9 millimetres WG per unit length to 3.5 millimetres WG per unit length, preferably from 0.9 millimetres WG per unit length to 3.25 millimetres WG per unit length, more preferably from 0.9 millimetres WG per unit length to 3 millimetres WG per unit length.

[0115] For example, an RTD of a plug element in accordance with the present invention may be from 1 millimetre WG per unit length to 3.5 millimetres WG per unit length, preferably from 1 millimetre WG per unit length to 3.25 millimetres WG per unit length, more preferably from 1 millimetre WG per unit length to 3 millimetres WG per unit length.

[0116] For example, an RTD of a plug element in accordance with the present invention may be from 1.2 millimetres WG per unit length to 3.5 millimetres WG per unit length, preferably from 1.2 millimetres WG per unit length to 3.25 millimetres WG per unit length, more preferably from 1.2 millimetres WG per unit length to 3 millimetres WG per unit length.

[0117] For example, an RTD of a plug element in accordance with the present invention may be from 1.5 millimetres WG per unit length to 3.5 millimetres WG per unit length, preferably from 1.5 millimetres WG per unit length to 3.25 millimetres WG per unit length, more preferably from 1.5 millimetres WG per unit length to 3 millimetres WG per unit length.

[0118] For example, an RTD of a plug element in accordance with the present invention may be from 1.75 millimetres WG per unit length to 3.5 millimetres WG per unit length, preferably from 1.75 millimetres WG per unit length to 3.25 millimetres WG per unit length, more preferably from 1.75 millimetres WG per unit length to 3 millimetres WG per unit length.

[0119] For example, an RTD of a plug element in accordance with the present invention may be from 2.0 millimetres WG per unit length to 3.5 millimetres WG per unit length, preferably from 2.0 millimetres WG per unit length to 3.25 millimetres WG per unit length, more preferably from 2.0 millimetres WG per unit length to 3 millimetres WG per unit length.

[0120] In certain embodiments, the paper material is a processed paper material selected from glassine paper, parchment paper, and natural greaseproof paper.

[0121] Glassine paper, parchment paper and natural greaseproof paper (such as Nordic Paper Perga® or Superperga®) are processed paper materials with a comparatively high density, typically close to or higher than 1 gram / cubic centimetre. Preferred values of density for the processed paper material used in the plug of aerosol-generating articles in accordance with the present invention will be discussed in more detail below.

[0122] To achieve such a comparatively high density values falling within these ranges, the sheet of paper material obtained from pressing and drying the mat of randomly interwoven fibres, as described above, is then typically thinned, and the surface of the sheet of paper material is typically smoothed by pressing the sheet of paper material between metal cylinders or rollers, which are also referred to as calenders. ThisP408336WQ - 14 January 2026 FTR4090 / PCT - 14 - operation, denoted as “calendering”, is typically the last step of the papermaking process before the paper material is cut to standard sizes. Calendering may be carried out at high temperature, optionally in presence of plasticisers or mineral fillers (for example, calcium carbonate).

[0123] As used herein with reference to the present invention, the term “glassine paper” is used to denote a paper material that has been subjected to a supercalendering process. In fact, glassine paper is often also referred to as “supercalendered paper”.

[0124] To make glassine paper, after the sheet of paper material has been thinned by the calendering process, the sheet of paper is fed through an additional set of calenders called “supercalender”. The supercalender consists of several cylinders alternating between polished metal and soft resilient surfaces (also called “nips”), typically provided as fibre-covered cylinders. The supercalender runs at high speed and applies pressure, heat, and friction to the sheet of paper material. Once compressed, the fibres defining the soft resilient surfaces struggle to return to their original dimensions, and thus they buff the sheet of paper material passing through the nips.

[0125] The force generated by each progressive nip is understood to polish both surfaces of the sheet of paper material. Without wishing to be bound by theory, this is understood to be due to the supercalendering process breaking down the capillaries of the cellulose fibres at a cellular level. This imparts the sheet of paper material undergoing supercalendering a highly closed surface, along with improved density and very low porosity. As a result, glassine paper is typically more resistant to grease and moisture than nonsupercalendered paper materials. Additionally, both sides of a sheet of glassine paper tend to have a smooth and glossy finish.

[0126] Further details about how glassine paper can be manufactured can be found in US 2792765 A. As used herein with reference to the present invention, the term “parchment paper” is used to denote a paper material which has been treated with sulphuric acid to impart the paper material enhanced non-stick or release properties. To make parchment paper, the sheet of paper pulp is run through a bath of sulphuric acid, which has the effect of partially dissolving and fusing together the pulp fibres. Without wishing to be bound by theory, this is understood to form a sulphurised, cross-linked structure, which displays comparatively high density in combination with good heat resistance, grease resistance, water resistance, and generally low surface energy. At the end of its manufacturing process, parchment paper -which is also at times referred to as “vegetable parchment” - has an appearance similar to that of parchment.

[0127] Further details about how parchment paper can be manufactured can be found in US 1334843 A. The term “greaseproof paper” is commonly used to refer to a refined paper material that has been made impermeable to oil or grease. These properties make greaseproof paper particularly suitable for use in cooking and food packaging. As used herein with reference to the present invention, the term “natural greaseproof paper” is used to denote a greaseproof paper obtained by subjecting the paper material to a beating process, whereby a great number of bonding sites are formed on each fibre, which in turn enhances the overall density of the paper material. Without wishing to be bound by theory, it is understood that this process imparts the paper material a closed surface structure with a rather small number of large surface pores. Thus, natural greaseproof paper combines comparatively high density with a very low porosity. For example, Scandinavian company Nordic Paper offers for sale natural greaseproof paper whose barrier properties make it an alternative to paper materials treated with fluorochemicals.P408336WQ - 14 January 2026 FTR4090 / PCT - 15 - Subjecting the paper material to a supercalendering process (as in the case of glassine paper) or to a high degree of beating (as in the case of natural greaseproof paper) or to sulphuric acid treatment (as in the case of parchment paper) has advantageously been found to significantly lessen the impact of the cellulosic filtration material of the plug element on the taste of the smoke or aerosol provided to the consumer during use of an aerosol-generating article comprising the plug element. In fact, forming the plug element from a cellulosic filtration material comprising one of the selected paper materials listed above has been observed to desirably reduce or even eliminate any harsh and dry sensation referred to by consumers as “paper taste” and often associated with smoke or aerosol that has flown through filter elements made of other paper materials not treated as described above.

[0128] In some embodiments, the paper material is glassine paper manufactured from highly refined kraft pulp or anthraquinone soda pulp.

[0129] As part of the papermaking process, fillers may be added to the pulp fibres prior to the formation of the web. Thus, in an aerosol-generating article according to the present invention, the sheet of paper material may comprise one or more fillers.

[0130] Fillers used in the papermaking process are ordinarily inorganic, particulate substances, typically in the size range of 0.1 to 10 micrometres that may impart certain desirable properties to the paper material. For example, fillers may have an impact on the structure, appearance (for example, brightness and opacity), density, tensile strength and other measurable properties of the paper material. Examples of commonly used papermaking fillers include clay, limestone, chalk, talc, calcite (calcium carbonate), rutile (titanium dioxide), calcium sulphate, amorphous silica.

[0131] As a result of the supercalendering process, glassine paper is translucent, unless dyes are added to colour it or make it opaque. Glassine paper for use in the manufacture of a plug element of an aerosolgenerating article in accordance with the present invention may include one or more of the papermaking fillers described above. The addition of such commonly used papermaking fillers may be desirable in that it may alter the visual impact of glassine paper by at least partly reducing its translucency.

[0132] In some preferred embodiments, the glassine paper comprises calcium carbonate. On top of being highly compatible with the supercalendering process, the additional of calcium carbonate may advantageously further increase the density of the glassine paper.

[0133] In a plug element according to the present invention, the inventors have found that applying a three-dimensionally patterned surface to a sheet of glassine paper modifies its surface structure. In particular an embossed or debossed pattern rearranges the fibres of the paper surface, forming a series of recesses, ridges and cavities which increase the effective surface area of the glassine paper and enable improved retention of additive coatings applied to the surface. Furthermore, the inventors have observed that, compared with known sheets of glassine paper the patterned surface permits improved absorption and uniform retention of additive coatings, such as those comprising additives for reducing phenols.

[0134] Without wishing to be bound by theory, it is understood that providing a three-dimensionally patterned surface to the glassine paper produces a technical effect that cannot be achieved by conventional surface modification techniques, such as crimping, wherein the resulting surface irregularities are insufficient to enable effective uptake of an additive coating. In contrast, the embossing process of the present invention allows precise control over the geometry and depth of surface features, thereby ensuring reproducible retention of additive coatings while maintaining the mechanical rigidity, dimensional stability, and low intrinsic filtration properties of the paper. In addition, the method is compatible with existingP408336WQ - 14 January 2026 FTR4090 / PCT - 16 - manufacturing equipment and production lines, allowing for seamless integration without substantial modification of machinery or processes. The controlled embossing and subsequent application of additive coatings facilitates the production of plug elements with enhanced functional performance, improved additive coating efficiency, and increased product consistency, thereby addressing both biodegradability requirements and consumer expectations for sustainable and effective products.

[0135] Optionally, the sheet of glassine paper may comprise the first surface and an opposing, second surface. The second surface may comprise a second three-dimensionally patterned surface.

[0136] Optionally, the, or each, three-dimensionally patterned surface of the sheet may comprise one or both of: a debossed pattern or an embossed pattern.

[0137] Optionally, the, or each, three-dimensionally patterned surface may be a regular, repeating pattern. Optionally, the, or each, three-dimensionally patterned surface may be distributed over an entire surface of the sheet.

[0138] Optionally, the additive coating may comprise at least one of triacetin or polyethylene glycol. Optionally, the additive coating may comprise a mixture of triacetin and polyethylene glycol. Optionally, the mixture may comprise a ratio of polyethylene glycol : triacetin of around 50: 50. Optionally, the mixture may comprise a ratio of polyethylene glycol : triacetin of around 60: 40. Optionally, the mixture may comprise a ratio of polyethylene glycol : triacetin of around 70: 30. Optionally, the mixture may comprise a ratio of polyethylene glycol : triacetin of around 80: 20. Optionally, the mixture may comprise a ratio of polyethylene glycol : triacetin of around 90: 10.

[0139] Optionally, the sheet of glassine paper may be configured to operably define one or more airflow channels extending through the plug element. Optionally, the airflow channels may be arranged between the sheet and oriented along an axial airflow direction of the plug element.

[0140] Optionally, the downstream section may comprise a hollow tubular element abutting a downstream end of the rod of aerosol-generating substrate, the downstream element located downstream of the hollow tubular element. Optionally, the hollow tubular element may comprise a cardboard material.

[0141] Optionally, the downstream element may be a mouthpiece filter segment comprising the plug element and a filter wrapper circumscribing the plug element.

[0142] Optionally, a method of manufacturing a plug element may comprise treating the sheet of glassine paper by applying one or both of an embossed pattern or a debossed pattern.

[0143] Optionally, the method may include:

[0144] gathering the embossed or debossed sheet of paper material to form a continuous rod of cellulosic filtration material; and

[0145] cutting the continuous rod of cellulosic filtration material into a plurality of plug elements; wherein the step of gathering the embossed or debossed sheet of paper material is carried out immediately after the step of embossing or debossing the sheet of paper material.

[0146] Optionally, a method of manufacturing a plug element may comprise at least partly impregnating the first surface by dispersing droplets onto the sheet of glassine paper, wherein the droplets comprise a liquid phase comprising the additive coating. Optionally, the method may comprise using pressurised nozzles to disperse the droplets.

[0147] In an aerosol-generating article according to the present invention, the sheet of paper material may have a density of at least 0.65 grams / cubic centimetre. Preferably, the sheet of paper material has a density of at least 0.75 grams / cubic centimetre. More preferably, the sheet of paper material has a density of atP408336WQ - 14 January 2026 FTR4090 / PCT - 17 - least 0.85 grams / cubic centimetre. Even more preferably, the sheet of paper material has a density of at least 0.95 grams / cubic centimetre.

[0148] In particularly preferred embodiments, the sheet of paper material has a density of at least 1 gram / cubic centimetre.

[0149] In an aerosol-generating article according to the present invention, the sheet of paper material may have a density up to 1 .55 grams / cubic centimetre. Preferably, the sheet of paper material has a density of less than or equal to 1.45 grams / cubic centimetre. More preferably, the sheet of paper material has a density of less than or equal to 1.35 grams / cubic centimetre. Even more preferably, the sheet of paper material has a density of less than or equal to 1.25 grams / cubic centimetre.

[0150] In particularly preferred embodiments, the sheet of paper material has a density of less than or equal to 1.15 grams / cubic centimetre.

[0151] For example, the sheet of paper material may have a density from 0.65 grams / cubic centimetre to 1.55 grams / cubic centimetre, preferably from 0.65 grams / cubic centimetre to 1.45 grams / cubic centimetre, more preferably from 0.65 grams / cubic centimetre to 1.35 grams / cubic centimetre, even more preferably from 0.65 grams / cubic centimetre to 1.25 grams / cubic centimetre, and particularly preferably from 0.65 grams / cubic centimetre to 1.15 grams / cubic centimetre.

[0152] For example, the sheet of material may have a density from 0.75 grams / cubic centimetre to 1.55 grams / cubic centimetre, preferably from 0.75 grams / cubic centimetre to 1.45 grams / cubic centimetre, more preferably from 0.75 grams / cubic centimetre to 1.35 grams / cubic centimetre, even more preferably from 0.75 grams / cubic centimetre to 1.25 grams / cubic centimetre, and particularly preferably from 0.75 grams / cubic centimetre to 1.15 grams / cubic centimetre.

[0153] For example, the sheet of paper material may have a density from 0.85 grams / cubic centimetre to 1.55 grams / cubic centimetre, preferably from 0.85 grams / cubic centimetre to 1.45 grams / cubic centimetre, more preferably from 0.85 grams / cubic centimetre to 1.35 grams / cubic centimetre, even more preferably from 0.85 grams / cubic centimetre to 1.25 grams / cubic centimetre, and particularly preferably from 0.85 grams / cubic centimetre to 1.15 grams / cubic centimetre.

[0154] For example, the sheet of paper material may have a density from 0.95 grams / cubic centimetre to 1.55 grams / cubic centimetre, preferably from 0.95 grams / cubic centimetre to 1.45 grams / cubic centimetre, more preferably from 0.95 grams / cubic centimetre to 1.35 grams / cubic centimetre, even more preferably from 0.95 grams / cubic centimetre to 1.25 grams / cubic centimetre, and particularly preferably from 0.95 grams / cubic centimetre to 1.15 grams / cubic centimetre.

[0155] For example, the sheet of paper material may have a density from 1 gram / cubic centimetre to 1 .55 grams / cubic centimetre, preferably from 1 gram / cubic centimetre to 1.45 grams / cubic centimetre, more preferably from 1 gram / cubic centimetre to 1.35 grams / cubic centimetre, even more preferably from 1 gram / cubic centimetre to 1.25 grams / cubic centimetre, and particularly preferably from 1 gram / cubic centimetre to 1.15 grams / cubic centimetre.

[0156] In an aerosol-generating article according to the present invention, the sheet of paper material may have a grammage of at least 35 gsm. Preferably, the sheet of paper material has a grammage of at least 40 gsm. More preferably, the sheet of paper material has a grammage of at least 45 gsm. Even more preferably, the sheet of paper material has a grammage of at least 50 gsm.

[0157] In an aerosol-generating article according to the present invention, the sheet of paper material may have a grammage of up to 110 gsm. Preferably, the sheet of paper material has a grammage of less thanP408336WQ - 14 January 2026 FTR4090 / PCT - 18 - or equal to 100 gsm. More preferably, the sheet of d paper material has a grammage of less than or equal to 80 gsm. Even more preferably, the sheet of paper material has a grammage of less than or equal to 60 gsm.

[0158] For example, the sheet of paper material may have a grammage from 35 gsm to 110 gsm, preferably from 35 gsm to 100 gsm, more preferably from 35 gsm to 80 gsm, even more preferably from 35 gsm to 60 gsm.

[0159] For example, the sheet of paper material may have a grammage from 40 gsm to 110 gsm, preferably from 40 gsm to 100 gsm, more preferably from 40 gsm to 80 gsm, even more preferably from 40 gsm to 60 gsm.

[0160] For example, the sheet of paper material may have a grammage from 45 gsm to 110 gsm, preferably from 45 gsm to 100 gsm, more preferably from 45 gsm to 80 gsm, even more preferably from 45 gsm to 60 gsm.

[0161] For example, the sheet of paper material may have a grammage from 50 gsm to 110 gsm, preferably from 50 gsm to 100 gsm, more preferably from 50 gsm to 80 gsm, even more preferably from 50 gsm to 60 gsm.

[0162] The grammage of the sheet of paper material may be selected based on a balance between the ability of the plug element to withstand a compressive load during use, and the need to preserve a certain pliability of the sheet of sheet of paper material to be able to form it into a desired shape. Further, the grammage of the sheet of paper material may be selected such that the plug element is able to resist deformation during storage, transportation and use of the aerosol-generating article.

[0163] The paper material may be in the form of a sheet having a thickness of up to 800 micrometres. Preferably, the sheet of paper material has a thickness of less than or equal to 600 micrometres. More preferably, the sheet of paper material has a thickness of less than or equal to 600 micrometres. Even more preferably, the sheet of paper material has a thickness of less than or equal to 500 micrometres.

[0164] In preferred embodiments, the sheet of paper material has a thickness of less than or equal to 300 micrometres, preferably less than or equal to 200 micrometres, more preferably less than or equal to 100 micrometres.

[0165] The sheet of paper material may have a thickness of at least 10 micrometres. Preferably, the sheet of paper material has a thickness of at least 15 micrometres. More preferably, the sheet of paper material has a thickness of at least 20 micrometres. Even more preferably, the sheet of paper material has a thickness of at least 30 micrometres.

[0166] In preferred embodiments, the sheet of paper material has a thickness of at least 40 micrometres, preferably at least 50 micrometres, more preferably at least 60 micrometres.

[0167] The thickness of the sheet of paper material may be selected to ensure a certain pliability of the sheet, so as to facilitate one or more of gathering and folding of the sheet.

[0168] In a plug element according to the present invention, the sheet of paper material may for example have a width of up to 300 millimetres.

[0169] In preferred embodiments, in a plug element according to the present invention, the sheet of paper material may have a width of less than 300 millimetres.

[0170] Preferably, the sheet of paper material has a width of less than or equal to 275 millimetres. More preferably, the sheet of paper material has a width of less than or equal to 250 millimetres. Even more preferably, the sheet of paper material has a width of less than or equal to 225 millimetres.P408336WQ - 14 January 2026 FTR4090 / PCT - 19 - In a plug element according to the present invention, the sheet of paper material may for example have a width of at least 150 millimetres.

[0171] Preferably, the sheet of paper material has a width of at least 160 millimetres. More preferably, the sheet of paper material has a width of at least 175 millimetres. Even more preferably, the sheet of paper material has a width of at least 190 millimetres.

[0172] For example, the sheet of paper material may have a width from 150 millimetres to 300 millimetres, preferably from 150 millimetres to 275 millimetres, more preferably from 150 millimetres to 250 millimetres, even more preferably from 150 millimetres to 225 millimetres.

[0173] For example, the sheet of paper material may have a width from 160 millimetres to 300 millimetres, preferably from 160 millimetres to 275 millimetres, more preferably from 160 millimetres to 250 millimetres, even more preferably from 160 millimetres to 225 millimetres.

[0174] For example, the sheet of paper material may have a width from 175 millimetres to 300 millimetres, preferably from 175 millimetres to 275 millimetres, more preferably from 175 millimetres to 250 millimetres, even more preferably from 175 millimetres to 225 millimetres.

[0175] For example, the sheet of paper material may have a width from 190 millimetres to 300 millimetres, preferably from 190 millimetres to 275 millimetres, more preferably from 190 millimetres to 250 millimetres, even more preferably from 190 millimetres to 225 millimetres.

[0176] In general, varying the width of the sheet of paper material may be a way of adjusting an RTD of the plug element. Without wishing to be bound by theory, it is understood that, other geometric parameters of the plug element - such as length and diameter of the plug element - being the same, increasing the width of the sheet of paper material results in more paper material being gathered to fit into a given substantially cylindrical volume. Accordingly, upon increasing the width of the sheet of paper material, the void fraction within the plug element generally decrease, and with a decreased cross-sectional porosity, it can be expected that the RTD of the plug element will increase. However, if too wide a sheet of paper material is gathered into a continuous rod having a predetermined diameter, the continuous rod may display an undesirable level of rigidity and hardness, which makes cutting the continuous rod into discrete plug elements having a predetermined length difficult and may even damage the cutting apparatus.

[0177] Plug elements for use in an aerosol-generating article according to the present invention and comprising a sheet of embossed or debossed paper material having a width that falls within the ranges described above may have the advantage that satisfactory levels of RTD are achieved in combination with levels of firmness that are suitable for the consumer’s use and do not cause issues during manufacturing, especially during a cutting operation as referred to above.

[0178] The plug element may have a weight of less than or equal to about 100 milligrams, less than or equal to about 75 milligrams, or less than or equal to about 50 milligrams.

[0179] The plug element may have a weight of at least about 10 milligrams, at least about 15 milligrams, or at least about 20 milligrams.

[0180] The plug element may have a weight of between about 10 milligrams and about 100 milligrams, between about 10 milligrams and about 75 milligrams, or between about 10 milligrams and about 50 milligrams.

[0181] The plug element may have a weight of between about 15 milligrams and about 100 milligrams, between about 15 milligrams and about 75 milligrams, or between about 15 milligrams and about 50 milligrams.P408336WQ - 14 January 2026 FTR4090 / PCT - 20 - The plug element may have a weight of between about 20 milligrams and about 100 milligrams, between about 20 milligrams and about 75 milligrams, or between about 20 milligrams and about 50 milligrams.

[0182] The plug element may have an average weight per unit length of less than or equal to about 20 milligrams per millimetre, less than or equal to about 15 milligrams per millimetre, or less than or equal to about 10 milligrams per millimetre.

[0183] As used herein with reference to the invention, the average weight per unit length of the plug element is equal to the weight of the plug element divided by the length of the plug element. For example, where the plug element has a weight of 25 milligrams and a length of 5 millimetres, the average weight per unit length of the plug element is 5 milligrams per millimetre.

[0184] The plug element may have an average weight per unit length of at least about 2 milligrams per millimetre, at least about 3 milligrams per millimetre, or at least about 4 milligrams per millimetre.

[0185] The plug element may have an average weight per unit length of between about 2 milligrams per millimetre and about 20 milligrams per millimetre, between about 2 milligrams per millimetre and about 15 milligrams per millimetre, or between about 2 milligrams per millimetre and about 10 milligrams per millimetre.

[0186] The plug element may have an average weight per unit length of between about 3 milligrams per millimetre and about 20 milligrams per millimetre, between about 3 milligrams per millimetre and about 15 milligrams per millimetre, or between about 3 milligrams per millimetre and about 10 milligrams per millimetre.

[0187] The plug element may have an average weight per unit length of between about 4 milligrams per millimetre and about 20 milligrams per millimetre, between about 4 milligrams per millimetre and about 15 milligrams per millimetre, or between about 4 milligrams per millimetre and about 10 milligrams per millimetre.

[0188] In a plug element according to the present invention, the embossed or debossed sheet of paper material comprises an embossed or debossed pattern which is regularly spaced and distributed across at least 50 percent of the sheet surface.

[0189] Preferably, in a plug element according to the present invention, the embossed or debossed sheet of paper material comprises an embossed or debossed pattern which is regularly spaced and distributed across at least 60 percent of the sheet surface. More preferably, in a plug element according to the present invention, the embossed or debossed sheet of paper material comprises an embossed or debossed pattern which is regularly spaced and distributed across at least 75 percent of the sheet surface. Even more preferably, in a plug element according to the present invention, the embossed or debossed sheet of paper material comprises an embossed or debossed pattern which is regularly spaced and distributed across at least 90 percent of the sheet surface.

[0190] In particularly preferred embodiments, the embossed or debossed sheet of paper material comprises an embossed or debossed pattern which is regularly spaced and distributed across the entire sheet surface.

[0191] Preferably, the cellulosic filtration material does not include cellulose acetate fibres or any other fibres formed of non-biodegradable polymers.

[0192] In a plug element for use in an aerosol-generating article according to the present invention, the cellulosic filtration material may comprise an additive coating applied to the processed paper material.P408336WQ - 14 January 2026 FTR4090 / PCT - 21 - As used herein, the term “phenols” refers to a class of chemical compounds consisting of a hydroxyl group ( — OH) bonded directly to an aromatic hydrocarbon group. The phenol group includes phenol, catechol, m+P cresols, and o-cresol.

[0193] As used herein, with reference to the present invention, the term “additive for reducing phenols” is used to denote any additive, which, when added to a mouthpiece of an aerosol-generating article, is capable of reducing the level of at least one of phenol, catechol, m+P cresols, and o-cresol in the smoke or aerosol, when subjected to a standard smoking test.

[0194] As used herein, the term “flue gases” is used to denote certain gaseous products generated by the combustion or pyrolysis of an aerosol-generating substrate.

[0195] The additive coating may comprise at least 5 percent by weight of an additive for reducing phenols. In plug elements for use in aerosol-generating articles in accordance with the present invention, the additive coating may cover at least part of the external surface of at least one side of the sheet of embossed or debossed paper material. Preferably, the additive coating covers at least part of the external surface of both sides of the sheet of embossed or debossed paper material.

[0196] The additive coating may be applied over a part of the external surface of at least one side of the sheet of embossed or debossed paper material. Preferably, the additive coating is applied over a part of the external surface of both sides of the sheet of embossed or debossed paper material.

[0197] Alternatively, the additive coating may be applied over substantially all of the external surface of at least one side of the sheet of embossed or debossed paper material. Preferably, the additive coating may be applied over substantially all of the external surface of at least one side of the sheet of embossed or debossed paper material.

[0198] Thus, in plug elements in accordance with the present invention, the additive coating may be applied to the embossed or debossed paper material to form a defined layer on at least part of the external surface of at least one side of the sheet of embossed or debossed paper material. In some embodiments, the additive coating may be applied to the embossed or debossed paper material to form a defined layer on at least part of the external surface of both sides of the embossed or debossed paper material. For example, this may be achieved by applying the additive coating to the embossed or debossed paper material by a conventional printing process (for example, gravure printing or flexographic printing) or by a known coating process (for example, curtain coating, reverse gravure, semi-flexo, rod-coating, blade coating, comma coating, slot die coating).

[0199] The application of the additive coating to the external surface of the embossed or debossed paper material advantageously maximises the contact between the mainstream smoke or aerosol passing through the plug element and the additive coating, when the plug element is used as a downstream element in an aerosol-generating article. This in turn maximises the capability of the additive coating to reduce phenols and other undesirable compounds in the smoke or aerosol.

[0200] However, depending on the porosity of the paper material and due to the natural tendency of the paper material to absorb liquids such as water, applying the additive coating to the embossed or debossed paper material may result in at least some of the additive coating permeating into the embossed or debossed paper material, so that at least some of the volume of the embossed or debossed paper material is soaked with additive coating. This may occur, in particular, if the additive coating is provided in the form of an aqueous solution or dispersion.P408336WQ - 14 January 2026 FTR4090 / PCT - 22 - Therefore, in plug elements in accordance with the present invention, the additive coating may alternatively, or additionally, be applied to the embossed or debossed paper material not so much to form a defined layer on at least part of the external surface of at least one side of the embossed or debossed paper material, but rather to at least partly impregnate the volume of the embossed or debossed paper material. In particular, the additive coating may be applied to a glassine paper with a three-dimensionally patterned surface. In such cases, the additive coating does not form a defined layer on the external surface of the embossed or debossed paper material. Instead, the additive coating is absorbed into the embossed or debossed paper material and, upon drying, forms a deposit onto the fibrous fraction of the embossed or debossed paper material (that is, on the individual cellulose fibres contained in the embossed or debossed paper material). For example, at least partial impregnation of the embossed or debossed paper material with the additive coating may be achieved by technologies such as “dip and squeeze”, spray application, comma application, or by using conventional or film type size presses or blade applicators. For example, at least partly impregnating a three-dimensionally patterned surface of a sheet of glassine paper with an additive coating may be achieved by dispersing droplets onto the sheet. The droplets may include a liquid phase comprising the additive coating.

[0201] The provision of such deposit of additive coating on the cellulose fibres of the embossed or debossed paper material advantageously ensures that, when the plug element is used as a downstream element in an aerosol-generating article, the mainstream smoke or aerosol passing through the plug element contacts the additive coating during use, and this interaction promotes the reduction of phenols and other undesirable compounds in the smoke or aerosol.

[0202] Thus, in certain embodiments, the plug element may comprise a cellulosic filtration material wherein the additive coating forms a defined layer on at least part of the external surface of at least one side of the embossed or debossed paper material. In other embodiments, the plug element may comprise a cellulosic filtration material wherein the additive coating has been absorbed into the embossed or debossed paper material and at least partly impregnates the volume of the embossed or debossed paper material. In further embodiments, the plug element may comprise a cellulosic filtration material wherein the additive coating has both been absorbed into the embossed or debossed paper material, and therefore at least partly impregnates the volume of the embossed or debossed paper material, and formed a defined layer on at least part of the external surface of at least one side of the embossed or debossed paper material.

[0203] Thus, in certain embodiments, impregnation of a glassine paper is improved by applying a three-dimensionally patterned surface to a sheet of glassine paper. The patterned surface modifies its surface structure to rearrange the fibres of the paper surface, forming a series of recesses, ridges and cavities that increase the effective surface area of the glassine paper and enable improved retention of additive coatings within the volume of the glassine paper.

[0204] The at least one additive for reducing phenols may be an ester of a polycarboxylic acid, such as for example an ester of oxalic acid, malonic acid, succinic acid, citric acid, isocitric acid. In preferred embodiments, the at least one additive for reducing phenols is an ester of citric acid, for example triethyl citrate (TEC).

[0205] The at least one additive for reducing phenols may be a polyether, preferably a polyol. As used herein, the term “polyol” denotes a polyether with multiple hydroxyl groups. Examples of polyether polyolsP408336WQ - 14 January 2026 FTR4090 / PCT - 23 - include polyethylene oxide, polyethylene glycol (PEG), polypropylene glycol (PPG), polytetrahydrofuran, and polytetramethylene ether glycol (PTMEG).

[0206] In preferred embodiments, the at least one additive for reducing phenols is polyethylene glycol (PEG).

[0207] The at least one additive for reducing phenols may comprise a derivative of PEG, such as an ester of PEG oligomers (such as diethylene glycol diacetate, tri-methylene glycol diacetate, etc.).

[0208] The at least one additive for reducing phenols may comprise a copolymer of PEG and PPG. Preferably, the at least one additive for reducing phenols is selected from the group consisting of triethyl citrate, polyethylene glycol, and combinations thereof.

[0209] The at least one additive for reducing phenols may be triacetin.

[0210] The at least one additive for reducing phenol may comprise an acetylated or a short-chain or medium-chain fatty acid plasticiser. For example, the at least one additive for reducing phenol may comprise an acetylated monoglyceride, a diester of isosorbide (such as isosorbide diacetate, isosorbide butyrate, etc.).

[0211] Preferably, the additive coating comprises at least 5 percent by weight of the at least one additive for reducing phenols, more preferably at least 6 percent by weight of the at least one additive for reducing phenols, more preferably at least 8 percent by weight of the at least one additive for reducing phenols, more preferably at least 10 percent by weight of the at least one additive for reducing phenols, on a dry weight basis.

[0212] Preferably, the additive coating comprises up to 20 percent by weight of the at least one additive for reducing phenols, more preferably up to 18 percent by weight of the at least one additive for reducing phenols, more preferably up to 15 percent the at least one additive for reducing phenols, more preferably up to 12 percent the at least one additive for reducing phenols, on a dry weight basis.

[0213] For example, the additive coating may comprise between 5 percent by weight and 20 percent by weight of the at least one additive for reducing phenols, or between 6 percent by weight and 20 percent by weight of the at least one additive for reducing phenols, or between 8 percent by weight and 20 percent by weight of the at least one additive for reducing phenols, or between 10 percent by weight and 20 percent by weight of the at least one additive for reducing phenols, or between 5 percent by weight and 18 percent by weight of the at least one additive for reducing phenols, or between 6 percent by weight and 18 percent by weight of the at least one additive for reducing phenols, or between 8 percent by weight and 18 percent by weight of the at least one additive for reducing phenols, or between 10 percent by weight and 18 percent by weight of the at least one additive for reducing phenols, or between 5 percent by weight and 15 percent by weight of the at least one additive for reducing phenols, or between 6 percent by weight and 15 percent by weight of the at least one additive for reducing phenols, or between 8 percent by weight and 15 percent by weight of the at least one additive for reducing phenols, or between 10 percent by weight and 15 percent by weight of the at least one additive for reducing phenols, or between 5 percent by weight and 12 percent by weight of the at least one additive for reducing phenols, or between 6 percent by weight and 12 percent by weight of the at least one additive for reducing phenols, or between 8 percent by weight and 12 percent by weight of the at least one additive for reducing phenols, or between 10 percent by weight and 12 percent by weight of the at least one additive for reducing phenols, on a dry weight basis.

[0214] By applying one such additive to the paper material of the plug element, the plug element is made capable of capturing or otherwise converting at least some of the phenols produced by the aerosol-P408336WQ - 14 January 2026 FTR4090 / PCT - 24 - generating article, when the plug element is used as a downstream element in the aerosol-generating article. The inclusion of the at least one additive for reducing phenols in the cellulosic filtration material therefore helps reduce the level of phenols in the mainstream aerosol as it passes through the downstream plug element from the aerosol-generating substrate whilst minimising any undesirable effects on the taste sensation experience by the consumer.

[0215] In aerosol-generating articles according to the invention an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is at least 0.5 percent by weight, preferably at least 1 percent by weight, more preferably at least 1.5 percent by weight, even more preferably at least 2 percent by weight.

[0216] In some embodiments, an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is at least 3 percent by weight, preferably at least 4 percent by weight, more preferably at least 5 percent by weight.

[0217] An overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis may be up to 15 percent by weight. Preferably an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is up to 12 percent by weight, more preferably up to 10 percent by weight.

[0218] For example, an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is from 0.5 percent by weight to 15 percent by weight, preferably from 1 percent by weight to 15 percent by weight, more preferably from 1.5 percent by weight to 15 percent by weight, even more preferably from 2 percent by weight to 15 percent by weight. In some embodiments, an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is from 3 percent by weight to 15 percent by weight, preferably from 4 percent by weight to 15 percent by weight, more preferably from 5 percent by weight to 15 percent by weight.

[0219] For example, an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is from 0.5 percent by weight to 12 percent by weight, preferably from 1 percent by weight to 12 percent by weight, more preferably from 1.5 percent by weight to 12 percent by weight, even more preferably from 2 percent by weight to 12 percent by weight. In some embodiments, an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is from 3 percent by weight to 12 percent by weight, preferably from 4 percent by weight to 12 percent by weight, more preferably from 5 percent by weight to 12 percent by weight.

[0220] For example, an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is from 0.5 percent by weight to 10 percent by weight, preferably from 1 percent by weight to 10 percent by weight, more preferably from 1.5 percent by weight to 10 percent by weight, even more preferably from 2 percent by weight to 10 percent by weight. In some embodiments, an overall content of the at least one additive for reducing phenols in the plug element on a dry weight basis is from 3 percent by weight to 10 percent by weight, preferably from 4 percent by weight to 10 percent by weight, more preferably from 5 percent by weight to 10 percent by weight.

[0221] The plug element may comprise at least 1 percent by weight of the additive coating. Preferably, the plug element comprises at least 2 percent by weight of the additive coating, more preferably at least 3 percent by weight of the additive coating, more preferably at least 4 percent by weight of the additive coating, more preferably at least 5 percent by weight of the additive coating, on a dry weight basis.P408336WQ - 14 January 2026 FTR4090 / PCT - 25 - The plug element may comprise up to 15 percent by weight of the additive coating, preferably up to 12 percent by weight of the additive coating, more preferably up to 10 percent by weight of the additive coating, on a dry weight basis.

[0222] The additive coating comprises at least one additive for reducing phenols. That is, the additive coating comprises at least one additive which is capable of capturing or otherwise converting at least some of the phenols and phenol derivatives produced upon heating or burning of the aerosol-generating substrate. Preferably, the additive coating comprises at least one additive for reducing other undesirable compounds from the mainstream aerosol, such as carbon monoxide and formaldehyde.

[0223] Preferably, the additive coating is biodegradable such that the cellulosic filtration material including the combination of additive coating and paper material is biodegradable.

[0224] In some embodiments, the additive coating may comprise at least one exogenous polysaccharide. The term “polysaccharide” generally identifies a polymeric carbohydrate composed of a long chain of monosaccharide units joined by glycosidic linkages with a general formula of (CeHioOsjn, with n typically in the range from 40 to 3000. Polysaccharides, which occur widely in nature, exhibit a molecular structure that can be linear or highly branched, and may be composed by multiple ones of the same monosaccharide unit (homopolysaccharides) or include different monosaccharide units (heteropolysaccharides). Common examples of polysaccharides found in plants include cellulose and starch. Glycogen is an example of a polysaccharide commonly found in most mammalian and nonmammalian cells. Chitin is a polysaccharide found in the exoskeletons of insects, the cell walls of fungi, and certain hard structures in invertebrates and fish.

[0225] As used herein with reference to the present invention, the term “exogenous polysaccharide” is used to denote a polysaccharide incorporated into the additive coating that may be applied to a plug element comprising a paper material which has a certain endogenous polysaccharide content. As discussed above, the pulp from which paper materials are made comprises compounds, such as cellulose and hemicellulose, which are in and of themselves, polysaccharides or mixtures of polysaccharides. Thus, the term “exogenous polysaccharide” is used to denote a polysaccharide that is provided in an isolated form and has been extracted and separated from other components of the material (for example, a plant material) from which it has been derived. The exogenous polysaccharide is therefore provided extrinsically from any cellulose or hemicellulose derived from plant material that is present in the pulp from which the processed paper material is made. In other words, the term “exogenous polysaccharide” refers to a separate and distinct source of polysaccharide to any polysaccharide provided intrinsically within the processed paper material.

[0226] Following application of exogenous polysaccharide to the processed paper material of the plug element, an “overall polysaccharide content” in the plug element is understood to be the sum of a) the endogenous cellulose and hemicellulose content present in the plug element prior to application of exogenous polysaccharide, and b) the amount of exogenous polysaccharide applied to the paper material.

[0227] The additive coating may comprise at least 5 percent by weight of the at least one exogenous polysaccharide, on a dry weight basis. Preferably, the additive coating comprises at least 6 percent by weight of the at least one exogenous polysaccharide, more preferably at least 8 percent by weight of exogenous polysaccharide, more preferably at least 10 percent by weight of the at least one exogenous polysaccharide, more preferably at least 12 percent by weight of the at least one exogenousP408336WQ - 14 January 2026 FTR4090 / PCT - 26 - polysaccharide, more preferably at least 15 percent by weight of the at least one exogenous polysaccharide, on a dry weight basis.

[0228] The additive coating preferably comprises up to 50 percent by weight of the at least one exogenous polysaccharide, more preferably up to 45 percent by weight of the at least one exogenous polysaccharide, more preferably up to 40 percent by weight of the at least one exogenous polysaccharide, more preferably up to 35 percent by weight of the at least one exogenous polysaccharide, even more preferably up to 30 percent by weight of the at least one exogenous polysaccharide, on a dry weight basis.

[0229] For example, the additive coating may comprise between 5 percent by weight and 50 percent by weight of the at least one exogenous polysaccharide, or between 6 percent by weight and 50 percent by weight of the at least one exogenous polysaccharide, or between 8 percent by weight and 50 percent by weight of the at least one exogenous polysaccharide, or between 10 percent by weight and 50 percent by weight of the at least one exogenous polysaccharide, or between 12 percent by weight and 50 percent by weight of the at least one exogenous polysaccharide, or between 15 percent by weight and 50 percent by weight of the at least one exogenous polysaccharide, or between 5 percent by weight and 45 percent by weight of the at least one exogenous polysaccharide, or between 6 percent by weight and 45 percent by weight of the at least one exogenous polysaccharide, or between 8 percent by weight and 45 percent by weight of the at least one exogenous polysaccharide, or between 10 percent by weight and 45 percent by weight of the at least one exogenous polysaccharide, or between 12 percent by weight and 45 percent by weight of the at least one exogenous polysaccharide, or between 15 percent by weight and 45 percent by weight of the at least one exogenous polysaccharide, or between 5 percent by weight and 40 percent by weight of the at least one exogenous polysaccharide, or between 6 percent by weight and 40 percent by weight of the at least one exogenous polysaccharide, or between 8 percent by weight and 40 percent by weight of the at least one exogenous polysaccharide, or between 10 percent by weight and 40 percent by weight of the at least one exogenous polysaccharide, or between 12 percent by weight and 40 percent by weight of the at least one exogenous polysaccharide, or between 15 percent by weight and 40 percent by weight of the at least one exogenous polysaccharide, or between 5 percent by weight and 35 percent by weight of the at least one exogenous polysaccharide, or between 6 percent by weight and 35 percent by weight of the at least one exogenous polysaccharide, or between 8 percent by weight and 35 percent by weight of the at least one exogenous polysaccharide, or between 10 percent by weight and 35 percent by weight of the at least one exogenous polysaccharide, or between 12 percent by weight and 35 percent by weight of the at least one exogenous polysaccharide, or between 15 percent by weight and 35 percent by weight of the at least one exogenous polysaccharide, or between 5 percent by weight and 30 percent by weight of the at least one exogenous polysaccharide, or between 6 percent by weight and 30 percent by weight of the at least one exogenous polysaccharide, or between 8 percent by weight and 30 percent by weight of the at least one exogenous polysaccharide, or between 10 percent by weight and 30 percent by weight of the at least one exogenous polysaccharide, or between 12 percent by weight and 30 percent by weight of the at least one exogenous polysaccharide, or between 15 percent by weight and 30 percent by weight of the at least one exogenous polysaccharide, on a dry weight basis.

[0230] The at least one exogenous polysaccharide provides numerous active functional groups, such as hydroxymethyl group, that are capable of scavenging from the smoke or aerosol certain gaseous compounds that may play a role in causing the dry and bitter sensation that has often been associated withP408336WQ - 14 January 2026 FTR4090 / PCT - 27 - conventional paper filters. These compounds may include, but are not limited to, weakly acidic compounds such as some aldehydes, as well as certain esters, ketones, alcohols, and pyrroles.

[0231] The inclusion of the at least one exogenous polysaccharide in the amounts described before therefore reduces the content of such compounds in the mainstream smoke or aerosol as it passes through the downstream plug element from the aerosol-generating substrate.

[0232] In aerosol-generating articles according to the invention an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis may be at least 5 percent by weight, and is preferably at least 6 percent by weight, more preferably at least 7 percent by weight, even more preferably at least 8 percent by weight.

[0233] An overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis may be up to 20 percent by weight. Preferably an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis is up to 18 percent by weight, more preferably up to 15 percent by weight, even more preferably up to 12 percent by weight. In some embodiments, an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis is up to 10 percent by weight.

[0234] For example, an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis is from 5 percent by weight to 20 percent by weight, preferably from 6 percent by weight to 20 percent by weight, more preferably from 7 percent by weight to 20 percent by weight, even more preferably from 8 percent by weight to 20 percent by weight.

[0235] For example, an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis is from 5 percent by weight to 18 percent by weight, preferably from 6 percent by weight to 18 percent by weight, more preferably from 7 percent by weight to 18 percent by weight, even more preferably from 8 percent by weight to 18 percent by weight.

[0236] For example, an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis is from 5 percent by weight to 15 percent by weight, preferably from 6 percent by weight to 15 percent by weight, more preferably from 7 percent by weight to 15 percent by weight, even more preferably from 8 percent by weight to 15 percent by weight.

[0237] For example, an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis is from 5 percent by weight to 12 percent by weight, preferably from 6 percent by weight to 12 percent by weight, more preferably from 7 percent by weight to 12 percent by weight, even more preferably from 8 percent by weight to 12 percent by weight.

[0238] For example, an overall content of the at least one exogenous polysaccharide in the plug element on a dry weight basis is from 5 percent by weight to 10 percent by weight, preferably from 6 percent by weight to 10 percent by weight, more preferably from 7 percent by weight to 10 percent by weight, even more preferably from 8 percent by weight to 10 percent by weight.

[0239] The at least one exogenous polysaccharide is preferably selected from the group consisting of starch, modified starch, alkenyl succinate starches, pullulan, alginate, and combinations thereof. Suitable types of starch include, but are not limited to, potato starch and corn starch.

[0240] The term “starch” is used herein with reference to the present invention to denote a polymeric carbohydrate consisting of multiple glucose units joined by a-(1— >4)-D glycosidic bonds. In nature, starch is produced in most green plants for energy storage purposes.P408336WQ - 14 January 2026 FTR4090 / PCT - 28 - From a chemical viewpoint, starch consists primarily of two types of molecules: amylose and amylopectin. Amylose is characterised by a linear, helical structure, whereas amylopectin is highly branched. Different types of starch typically contain different proportions of amylose and amylopectin. For example, potato starch and corn starch contain amylopectin and amylose in an approximately 3:1 ratio, whereas waxy maize starch is almost entirely formed of amylose.

[0241] In some embodiments, the at least one exogenous polysaccharide is a modified starch, such as oxidized waxy potato starch or an acetylated starch.

[0242] Acetylated starch is a form of modified starch, which has been modified to increase the number of acetyl groups. As a result of the increased number of acetyl groups, the use of acetylated starch may improve the capabilities of starch in reducing phenols from the mainstream aerosol.

[0243] Without wishing to be bound by theory, the introduction of acetyl groups is understood to also have an impact on wettability of the paper material. In fact, the esterification reaction that occurs between the acetyl groups and at least some hydroxyl groups in the cellulose molecules induces a change in the nature of at least some of the cellulose fibres from hydrophilic to hydrophobic. Thus, the paper material to which an additive coating comprising acetylated starch has been applied may have a reduced tendency to absorb moisture from the smoke or aerosol flowing through the plug element. This is desirable in that it may counter the effect, which has been observed with some conventional cellulose acetate filters and is often referred to as ‘dry smoke’, whereby the smoke or aerosol delivered to the consumer has a significantly reduced moisture content and may, therefore, under certain conditions, be perceived as undesirably dry. Further, increasing the contact angle of the paper material contact angle, such as for example increasing the contact angle of the paper material to greater than 90 degrees, preferably to greater than 105 degrees, may advantageously reduce the ability of the paper material to scavenge nicotine from the smoke or aerosol.

[0244] Preferably, the plug element comprising the cellulosic filtration material has an average radial hardness of at least 75 percent, more preferably at least 80 percent, more preferably at least 85 percent. Preferably, the plug element has a radial hardness of less than 100 percent, more preferably less than 95 percent.

[0245] As used herein, the term “radial hardness” refers to resistance to compression is a direction transverse to a longitudinal axis. Radial hardness of an aerosol-generating article around a filter may be determined by applying a load across the article at the location of the filter, transverse to the longitudinal axis of the article, and measuring the average (mean) depressed diameters of the articles. Radial hardness is given by:

[0246] Radial hardness (%) 100 %

[0247]

[0248] where Ds is the original (undepressed) diameter, and Dd is the depressed diameter after applying a set load for a set duration. The harder the material, the closer the hardness is to 100%.

[0249] To determine the hardness of a portion (such as a filter) of an aerosol-generating article, aerosolgenerating articles should be aligned parallel in a plane and the same portion of each aerosol-generating article to be tested should be subjected to a set load for a set duration. This test is performed using aP408336WQ - 14 January 2026 FTR4090 / PCT - 29 - known DD60A Densimeter device (manufactured and made commercially available by Heinr. Borgwaldt GmbH, Germany), which is fitted with a measuring head for aerosol-generating articles, such as cigarettes, and with an aerosol-generating article receptacle.

[0250] For the standard operating procedure for such an apparatus, an overall load of 2 kg is applied for a duration of 20 seconds. After 20 seconds have elapsed (and with the load still being applied to the smoking articles), the depression in the load applying cylindrical rods is determined, and then used to calculate the hardness from the above equation. The temperature is kept in the region of 22 degrees Centigrade ± 2 degrees. The test described above is referred to as the DD60A Test. The standard way to measure the filter hardness is when the aerosol-generating articles have not been consumed. Additional information regarding measurement of average radial hardness can be found in, for example, U.S. Published Patent Application Publication Number 2016 / 0128378.

[0251] As discussed briefly above, the present invention further provides a method of manufacturing a plug element in line with the foregoing description.

[0252] The method comprises a first step of providing a continuous sheet of paper material and a second step of embossing or debossing the continuous sheet of paper material to form a continuous embossed or debossed sheet of paper material.

[0253] Further, the method comprises a third step of gathering the embossed or debossed sheet of paper material to form a continuous rod of cellulosic filtration material.

[0254] Additionally, the method comprises a fourth step of cutting the continuous rod of cellulosic filtration material into a plurality of plug elements.

[0255] Ways of forming a continuous sheet material, such as a sheet of embossed or debossed paper material, into a rod-shaped plug element will be generally known to the skilled person, and may involve gathering or winding of the sheet material.

[0256] For example, a continuous sheet of embossed or debossed paper material can be fed through a converging funnel which gathers the continuous sheet transversely relative to its longitudinal axis. The embossed or debossed sheet assumes a substantially cylindrical configuration as it is provided with folds while it passes through the converging funnel.

[0257] Preferably, the third step of gathering the embossed or debossed sheet of paper material is carried out immediately after the second step of embossing or debossing the sheet of paper material.

[0258] The inventors have found that plug elements obtained by a method wherein the embossed or debossed sheet of paper is formed into a rod-shaped body immediately after the sheet of paper has been embossed or debossed are easier to manufacture and provide more consistent, satisfactory values of RTD.

[0259] Without wishing to be bound by theory, it is understood that the embossed or debossed structure formed in the sheet of paper material is not in any way altered prior to the embossed or debossed sheet being, for example, gathered into a cylinder, and this facilitate forming more regular folds in the sheet, which ultimately correspond to a more regular distribution of voids in the continuous rod and in the plug elements obtained by cutting the continuous rod. This has been confirmed by measuring the RTD of a plurality of plug elements and by determining an RTD coefficient of variation for the plurality of plug elements.

[0260] The term RTD coefficient of variation is used herein with reference to the invention to denote the product of the RTD standard deviation (as determined over a given number of plug elements) by 100.

[0261] For example, an RTD coefficient of variation for the plurality of plug elements obtained by the method may be less than 10.P408336WQ - 14 January 2026 FTR4090 / PCT - 30 - Preferably, an RTD coefficient of variation for the plurality of plug elements obtained by the method is less than 8. More preferably, an RTD coefficient of variation for the plurality of plug elements obtained by the method is less than 7. Even more preferably, an RTD coefficient of variation for the plurality of plug elements obtained by the method is less than 6. Most preferably, an RTD coefficient of variation for the plurality of plug elements obtained by the method is less than 5.

[0262] When used in an aerosol-generating article, a plug element in accordance with the present invention preferably further comprises a wrapper, for example a paper wrapper, circumscribing the gathered sheet of embossed or debossed paper material.

[0263] Therefore, the method preferably further comprises a step of wrapping the continuous rod of cellulosic filtration material prior to carrying out the fourth step of cutting the continuous rod of cellulosic filtration material into a plurality of plug elements.

[0264] For example, a paper wrapper may be wound about the sheet of embossed or debossed paper material being gathered in the forming cone, and overlapping edges of the paper wrapper may be bound together by applying an adhesive to a first edge of the wrapper and thereafter folding the other edge into contact with the first edge. The overlapping edges of the paper wrapper may be bound together by a heated roller, which both removes liquid and sets the adhesive.

[0265] The wrapper circumscribing the cellulosic filtration material may have a basis weight of at least 50 grams per square metre (gsm). Where the plug element is positioned at the downstream end of an aerosolgenerating article, this may help to provide a desired firmness for the aerosol-generating article. In certain embodiments, it may be desirable to use a stiff wrapper, for example, a wrapper having a basis weight of at least about 80 grams per square metre (gsm), or at least about 100 gsm, or at least about 110 gsm.

[0266] As discussed above, in some embodiments the cellulosic filtration material of a plug element for use in an aerosol-generating article according to the present invention further comprises an additive for reducing phenols. For example, such an additive coating may have been applied to the continuous sheet of paper material prior to it being embossed or debossed.

[0267] The additive coating may be applied to the paper material in any suitable manner. Preferably, the additive coating is applied to the paper material prior to the paper material being formed into the plug element.

[0268] The additive coating solution is formed by combining the dry ingredients of the additive coating and dispersing or dissolving them in water. The dry ingredients may include at least one additive for reducing phenols. The additive coating solution may optionally be heated prior to application of the solution to the processed paper material, for example, in order to bring about any necessary reactions between the components of the additive coating.

[0269] For example, in the step of applying the additive coating solution to the paper material, the additive coating solution may be applied to the paper material (typically in sheet form) by known printing processes, such as gravure printing or flexographic printing, or by known coating processes, like curtain coating, reverse gravure, semi-flexo, rod-coating, blade coating, comma coating, slot die coating. These processes may advantageously enable the formation of a defined layer of additive coating on at least part of an external surface of one or both sides of the processed paper material.

[0270] The additive coating solution may also be applied to the paper material prior to the paper material being embossed, for example by an impregnation process, such as by dipping the web of paper material into a bath of the additive coating or by spraying the additive coating solution onto the web of paper material,P408336WQ - 14 January 2026 FTR4090 / PCT - 31 - and letting the additive coating solution be at least partly absorbed into the web of paper material. Depending on how hydrophilic or hydrophobic the web of paper material is, the additive coating solution may permeate more or less deeply into the web of paper material or form more or less of a deposit of the additive coating on the external surface of at least one side of the web of paper material.

[0271] The sheet of paper material may subsequently be subjected to embossing or debossing.

[0272] As an alternative, in the step of applying the additive coating solution to the paper material, the additive coating solution may be applied to the paper material by injecting the additive coating solution into the plug element after the paper material has been processed and formed into a rod shape, or by dipping the formed plug element into a bath of the additive coating solution.

[0273] After the additive coating has been applied to the paper material, the thus treated paper material is preferably dried by any suitable means, including conventional heating, or microwave heating. Any curing of the additive coating may also be carried out during this drying step.

[0274] The step of drying the coated paper material, which may optionally comprise a curing of the coated paper material, may comprise heating the coated paper material using a conventional heater. Alternatively or in addition, the step of drying and optionally curing the coated paper material may comprise heating the coated paper material by microwave heating. The drying and optional curing of the additive coating solution is carried out in order to evaporate the water from the solution and to bring about curing of the additive coating or hardening of the additive coating or both.

[0275] As described above, a plug element in accordance with the foregoing description may be used in an aerosol-generating article. As such, the biodegradability of the aerosol-generating article will be improved compared to similar aerosol-generating articles including instead plug elements in the form of conventional cellulose acetate segments.

[0276] An example of an aerosol-generating article according to the present invention, as described briefly above, comprises a rod of aerosol-generating substrate; and a downstream section located downstream of the rod of aerosol-generating substrate; wherein the downstream section comprises a downstream element in axial alignment with the rod of aerosol-generating substrate, the downstream element comprising a plug element in line with the foregoing description.

[0277] For example, the downstream element is a mouthpiece filter segment comprising the plug element and a filter wrapper circumscribing the plug element.

[0278] In some embodiments, the aerosol-generating article is formed essentially of an aerosol-generating substrate and of a downstream element as described above provided in abutting arrangement with the rod of aerosol-generating substrate. For example, the aerosol-generating substrate may be in the form of a cylindrical rod of shredded tobacco material circumscribed by a wrapper, and the downstream element may be attached to the wrapped rod by a band of tipping paper so as to form a mouthpiece of the aerosolgenerating article.

[0279] In other embodiments, the aerosol-generating article comprises one or more additional elements also provided downstream of the aerosol-generating substrate and in axial alignment with the aerosolgenerating substrate. The downstream element comprising the plug element and any further element provided downstream of the aerosol-generating substrate and in axial alignment with the aerosolgenerating substrate form a downstream section of the aerosol-generating article.P408336WQ - 14 January 2026 FTR4090 / PCT - 32 - For example, the downstream section may further comprise a hollow tubular element abutting a downstream end of the rod of aerosol-generating substrate, the downstream element located downstream of the hollow tubular element.

[0280] In some preferred embodiments, the downstream element comprising the plug element is a mouthpiece element.

[0281] The aerosol-generating article may comprise a mouthpiece at the downstream end or mouth end or proximal end of the aerosol-generating article, the mouthpiece consisting of the plug element alone.

[0282] Alternatively, the aerosol-generating article may comprise a mouthpiece at the downstream end or mouth end or proximal end of the aerosol-generating article, the mouthpiece including the plug element and one or more further elements axially aligned in an abutting end to end relationship with each other. The plug element and the one or more further elements may be formed of the same material. Alternatively, the one or more further elements may be formed of a material other than the material of the plug element.

[0283] Parameters or characteristics described herein in relation to the plug element used as the sole component of the mouthpiece may equally be applied to a plug element used as one of multiple components of the mouthpiece.

[0284] Advantageously, aerosol-generating articles according to the present invention wherein the downstream element is a mouthpiece element provide an acceptable visual impact and tactile experience for the consumer, thanks to the density and firmness of the plug element. Additionally, in aerosolgenerating articles according to the present invention wherein the downstream element is a mouthpiece element, the cellulosic filtration material is capable of efficiently cooling a smoke or aerosol generated from the substrate, with little to no impact on the taste perceived by the consumer during use of the aerosolgenerating article. As such, aerosol-generating articles according to the present invention wherein the plug element is a mouthpiece element provide a much more sustainable alternative to aerosol-generating articles comprising a cellulose acetate filter segment as a mouthpiece filter segment.

[0285] The mouthpiece element may have a low particulate phase filtration efficiency or even substantially no particulate phase filtration efficiency. Whilst capable of preventing substrate material from the aerosolgenerating substrate potentially reaching the mouth of the consumer during use, a mouthpiece element having low particulate phase filtration efficiency has a reduced impact on delivery of aerosol species to the consumer. This is especially advantageous in aerosol-generating article wherein the aerosol-generating substrate is heated as opposed to being combusted.

[0286] In preferred embodiments, the particulate phase filtration efficiency of the plug element is less than about 30 percent, more preferably less than about 20 percent.

[0287] For example, the plug element used as the mouthpiece element may have an RTD of at least 55 millimetres WG, at least 60 millimetres WG, at least 65 millimetres WG, at least 70 millimetres WG, at least 75 millimetres WG, at least 80 millimetres WG, at least 85 millimetres WG, at least 90 millimetres WG, at least 95 millimetres WG or at least 100 millimetres WG.

[0288] For example, the plug element used as the mouthpiece element may have an RTD of less than or equal to 300 millimetres WG, less than or equal to 290 millimetres WG, less than or equal to 280 millimetres WG, less than or equal to 270 millimetres WG, less than or equal to 260 millimetres WG, less than or equal to 250 millimetres WG, less than or equal to 240 millimetres WG, less than or equal to 230 millimetres WG, less than or equal to 220 millimetres WG, less than or equal to 210 millimetres WG, less than or equal to 200 millimetres WG.P408336WQ - 14 January 2026 FTR4090 / PCT - 33 - Preferably, the mouthpiece element has a substantially circular cross-section.

[0289] Preferably, the mouthpiece element has an external diameter that is substantially the same as the external diameter of the aerosol-generating article.

[0290] A length of the mouthpiece may be at least about 3 millimetres, or at least about 5 millimetres. The length of the mouthpiece element may be less than or equal to about 11 millimetres, or less than or equal to about 9 millimetres.

[0291] The length of the mouthpiece element may be between about 3 millimetres and about 11 millimetres, or between about 3 millimetres and about 9 millimetres.

[0292] The length of the mouthpiece element may be between about 5 millimetres and about 11 millimetres, or between about 5 millimetres and about 9 millimetres.

[0293] For example, the length of the mouthpiece element may be about 7 millimetres.

[0294] The length of the mouthpiece element may be selected based on a desired total length of the aerosol-generating article.

[0295] The mouthpiece element may be circumscribed by a plug wrap.

[0296] The mouthpiece element may be unventilated such that air does not enter the aerosol-generating article along the mouthpiece element.

[0297] The mouthpiece element may be connected to one or more adjacent components of the aerosolgenerating article by means of a tipping wrapper.

[0298] The aerosol-generating article may define a mouth end cavity at the downstream end of the aerosol-generating article. For example, the mouthpiece element may itself be in the form of a hollow tubular element. As an alternative, the mouthpiece may include a non-hollow plug element as described above immediately upstream of a hollow tubular segment provided at the downstream end of the mouthpiece. As a further alternative, the mouth end cavity may be defined by an outer wrapper of the mouthpiece extending beyond a downstream end of a plug element as described above.

[0299] In some embodiments, the plug element may be an additional element provided downstream of the aerosol-generating substrate other than a mouthpiece element. That is, the aerosol-generating article comprises a mouthpiece and the plug element is provided between the aerosol-generating substrate and a mouthpiece of the aerosol-generating article.

[0300] For example, the downstream element may be a support element provided immediately downstream of the aerosol-generating substrate, preferably adjacent to the aerosol-generating substrate. One such support element is adapted to impart structural strength to the aerosol-generating article. The support element is advantageously configured to resist downstream movement of the aerosol-generating substrate during insertion of the heating element of the aerosol-generating device into the aerosolgenerating.

[0301] In some embodiments, the aerosol-generating article comprises an upstream section located upstream of the aerosol-generating substrate. The upstream section is preferably located immediately upstream of the aerosol-generating substrate. The upstream section preferably extends from an upstream end of the aerosol-generating article to an upstream end of the aerosol-generating substrate. The upstream section preferably comprises an upstream element located immediately upstream of the rod of aerosolgenerating substrate.P408336WQ - 14 January 2026 FTR4090 / PCT - 34 - Where the aerosol-generating substrate comprises shredded tobacco, such as tobacco cut filler, the upstream section or element thereof may additionally help to prevent the loss of loose particles of tobacco from the upstream end of the article.

[0302] The upstream section, or upstream element thereof, may also additionally provide a degree of protection to the aerosol-generating substrate during storage, as it covers at least to some extent the upstream end of the aerosol-generating substrate, which may otherwise be exposed. For aerosolgenerating articles that are intended to be inserted into a cavity in an aerosol-generating device such that the aerosol-generating substrate can be externally heated within the cavity, the upstream section, or upstream element thereof, may advantageously facilitate the insertion of the upstream end of the article into the cavity.

[0303] An upstream element of the upstream section may be made of any material suitable for use in an aerosol-generating article. The upstream element may, for example, be made of a same material as used for one of the other components of the aerosol-generating article, such as the mouthpiece, the aerosolcooling element or the support element, the geometry and function of which have been described above. Suitable materials for forming the upstream element include filter materials, ceramic, polymer material, cellulose acetate, cardboard, zeolite or aerosol-generating substrate.

[0304] In preferred embodiments, a plug element in accordance with the present invention is used as the upstream element.

[0305] From an environmental perspective, this is advantageous in that a greater portion of the aerosolgenerating article as a whole is more readily degradable. Additionally, from a manufacturing viewpoint, it is advantageous to form different components of a same aerosol-generating article of the same material, as it will generally require less adjustments to the settings of existing apparatus.

[0306] Preferably, the upstream section, or an upstream element thereof, has an external diameter that is approximately equal to the external diameter of the aerosol-generating article. Preferably, the external diameter of the upstream section, or an upstream element thereof, is between about 6 millimetres and about 8 millimetres, more preferably between about 7 millimetres and about 7.5 millimetres. Preferably, the upstream section or an upstream element has an external diameter that is about 7.1 mm.

[0307] Preferably, the upstream section or an upstream element has a length of between about 2 millimetres and about 8 millimetres, more preferably between about 3 millimetres and about 7 millimetres, more preferably between about 4 millimetres and about 6 millimetres. In a particularly preferred embodiment, the upstream section or an upstream element has a length of about 5 millimetres. The length of the upstream section or an upstream element can advantageously be varied in order to provide the desired total length of the aerosol-generating article.

[0308] The upstream section is preferably circumscribed by a wrapper, such as a plug wrap. The wrapper circumscribing the upstream section may be a stiff plug wrap, for example, a plug wrap having a basis weight of at least about 80 grams per square metre (gsm), or at least about 100 gsm, or at least about 110 gsm. This provides increased structural rigidity to the upstream section.

[0309] The upstream section is preferably connected to the rod of aerosol-generating substrate and optionally at least a part of the downstream section by means of an outer wrapper.

[0310] The aerosol-generating article may be a combustible smoking article. A combustible smoking article typically comprises a cylindrical rod of tobacco cut filler surrounded by a paper wrapper and a cylindrical filter axially aligned, most often in an abutting end-to-end relationship, with the wrapped tobaccoP408336WQ - 14 January 2026 FTR4090 / PCT - 35 - rod. The cylindrical filter typically comprises one or more plug elements of a fibrous filtration material circumscribed by a paper plug wrap. The wrapped tobacco rod and the filter are typically joined by a band of tipping wrapper, that circumscribes the entire length of the filter and an adjacent portion of the wrapped tobacco rod. In combustible smoking articles according to the present invention, the cylindrical filter comprises a downstream element comprising a plug element having the characteristics described above.

[0311] The aerosol-generating article may be an aerosol-generating article for generating an aerosol upon heating (a heated aerosol-generating article). A heated aerosol-generating article typically comprises a cylindrical rod of aerosol-generating substrate surrounded by a paper wrapper and a downstream section downstream of the rod of aerosol-generating substrate. The downstream section typically comprises at least one hollow tubular element immediately downstream of the rod of aerosol-generating substrate and a mouthpiece.

[0312] The aerosol-generating article preferably has an overall length of from 40 millimetres to 80 millimetres, or from 40 millimetres to about 70 millimetres, or from 40 millimetres to about 60 millimetres, or from 45 millimetres to about 80 millimetres, or from about 45 millimetres to about 70 millimetres, or from 45 millimetres to 60 millimetres, or from 50 millimetres to 80 millimetres, or from 50 millimetres to about 70 millimetres or from about 50 millimetres to about 60 millimetres. In an exemplary embodiment, an overall length of the aerosol-generating article is about 45 millimetres.

[0313] Preferably, the aerosol-generating article has a substantially circular cross-section.

[0314] The aerosol-generating article preferably has an external diameter of from about 5 millimetres to about 12 millimetres, or from about 6 millimetres to about 12 millimetres, or from about 7 millimetres to about 12 millimetres, or from about 5 millimetres to about 10 millimetres, or from about 6 millimetres to about 10 millimetres, or from about 7 millimetres to about 10 millimetres, or from about 5 millimetres to about 8 millimetres, or from about 6 millimetres to about 8 millimetres, or from about 7 millimetres to about 8 millimetres. In other embodiments, the aerosol-generating article has an external diameter of less than 7 millimetres.

[0315] The overall RTD of the aerosol-generating article is preferably at least 10 millimetres H2O, more preferably at least 15 millimetres H2O, more preferably at least 20 millimetres H2O, more preferably at least 25 millimetres H2O, more preferably at least 30 millimetres H2O.

[0316] The overall RTD of the aerosol-generating article is preferably no more than 70 millimetres H2O, more preferably no more than 60 millimetres H2O, more preferably no more than 55 millimetres H2O, more preferably no more than 50 millimetres H2O, more preferably no more than 45 millimetres H2O.

[0317] For example, the overall RTD of the aerosol-generating article may be between 10 millimetres H2O and 70 millimetres H2O, or between 15 millimetres H2O and 60 millimetres H2O, or between 20 millimetres H2O and 55 millimetres H2O, or between 25 millimetres H2O and 45 millimetres H2O, or between 30 millimetres H2O and 45 millimetres H2O.

[0318] As described above, an aerosol-generating article in accordance with the present invention comprises a rod of an aerosol-generating substrate. In several embodiments, the aerosol-generating article comprises a rod of aerosol-generating substrate circumscribed by a rod plug wrap.

[0319] Preferably, the rod of aerosol-generating substrate has a length of at least 8 millimetres, more preferably a length of at least 9 millimetres, more preferably a length of at least 10 millimetres. Preferably, the length of the rod of aerosol-generating substrate is less than 16 millimetres, more preferably less than 15 millimetres, more preferably less than 14 millimetres. For example, the rod of aerosol-generatingP408336WQ - 14 January 2026 FTR4090 / PCT - 36 - substrate may have a length of between 8 millimetres and 16 millimetres, or between 9 millimetres and 15 millimetres, or between 10 millimetres and 14 millimetres. In a particularly preferred embodiment, the rod of aerosol-generating substrate has a length of about 12 millimetres.

[0320] Preferably, the ratio between the length of the rod of aerosol-generating substrate and the overall length of the aerosol-generating article is at least 0.10, more preferably at least 0.15, more preferably at least 0.20, more preferably at least 0.25. Preferably, the ratio between the length of the rod of aerosolgenerating substrate and the overall length of the aerosol-generating article is 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 between the length of the rod of aerosol-generating substrate and the overall length of the aerosolgenerating article may be between 0.1 and 0.5, or between 0.15 and 0.45, or between 0.2 and 0.4, or between 0.25 and 0.35.

[0321] Preferably, the rod of aerosol-generating substrate has an external diameter that is approximately equal to the external diameter of the aerosol-generating article.

[0322] Preferably, the rod of aerosol-generating substrate has an external diameter of at least 5 millimetres, more preferably at least 6 millimetres, more preferably at least 7 millimetres. Preferably, the rod of aerosol-generating substrate has an external diameter of less than 12 millimetres, more preferably less than 10 millimetres, more preferably less than 8 millimetres. For example, the external diameter may be between 5 millimetres and 12 millimetres, or between 6 millimetres and 10 millimetres, or between 7 millimetres and 8 millimetres. In a particularly preferred embodiment, the rod of aerosol-generating substrate has an external diameter of about 7.1 millimetres.

[0323] Preferably, the rod of aerosol-generating substrate has a substantially uniform cross-section along the length of the rod. Particularly preferably, the rod of aerosol-generating substrate has a substantially circular cross-section.

[0324] The aerosol-generating substrate may have a density of at least about 150 milligrams per cubic centimetre, at least about 175 milligrams per cubic centimetre, at least about 200 milligrams per cubic centimetre, or at least about 250 milligrams per cubic centimetre.

[0325] The aerosol-generating substrate may have a density of less than or equal to about 500 milligrams per cubic centimetre, less than or equal to about 450 milligrams per cubic centimetre, less than or equal to about 400 milligrams per cubic centimetre, or less than or equal to about 350 milligrams per cubic centimetre.

[0326] The RTD of the rod of aerosol-generating substrate may be at least about 4 millimetres H2O, at least about 5 millimetres H2O, or at least about 6 millimetres H2O.

[0327] The RTD of the rod of aerosol-generating substrate may be less than or equal to about 10 millimetres H2O, less than or equal to about 9 millimetres H2O, or less than or equal to about 8 millimetres H2O.

[0328] 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, homogenised tobacco material such as cast leaf, aerosol-generating films and gel compositions.

[0329] The aerosol-generating substrate preferably comprises an aerosol former. Suitable aerosol formers are for example: polyhydric alcohols such as, for example, triethylene glycol, 1 ,3-butanediol, propylene glycol and glycerine; esters of polyhydric alcohols such as, for example, glycerol mono-, di- orP408336WQ - 14 January 2026 FTR4090 / PCT - 37 - triacetate; aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

[0330] Preferably, the aerosol former comprises one or more of glycerine and propylene glycol. The aerosol former may consist of glycerine or propylene glycol or of a combination of glycerine and propylene glycol.

[0331] In certain embodiments, the aerosol-generating substrate preferably comprises at least 5 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably at least 10 percent by weight on a dry weight basis, more preferably at least 15 percent by weight on a dry weight basis. In such embodiments, the aerosol-generating substrate preferably comprises no more than 30 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably no more than 25 percent by weight on a dry weight basis, more preferably no more than 20 percent by weight on a dry weight basis. For example, the aerosol former content of the aerosol-generating substrate may be between 5 percent and 30 percent by weight, or between 10 percent and 25 percent by weight, or between about 15 percent and about 20 percent by weight, on a dry weight basis. In such embodiments, the aerosol former content is therefore relatively low.

[0332] In other embodiments, the aerosol-generating substrate preferably comprises at least 40 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably at least 45 percent by weight on a dry weight basis, more preferably at least 50 percent by weight on a dry weight basis. In such embodiments, the aerosol-generating substrate preferably comprises no more than 80 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably no more than 75 percent by weight on a dry weight basis, more preferably no more than 70 percent by weight on a dry weight basis. For example, the aerosol former content of the aerosol-generating substrate may be between 40 percent and 80 percent by weight, or between 45 percent and 75 percent by weight, or between about 50 percent and about 70 percent by weight, on a dry weight basis. In such embodiments, the aerosol former content is therefore relatively high.

[0333] In some preferred embodiments, the aerosol-generating substrate comprises tobacco material. For example, the aerosol-generating substrate may comprise shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler, as described in more detail below. Alternatively, the shredded tobacco material may be in the form of a shredded sheet of homogenised tobacco material. Suitable homogenised tobacco materials for use in the present invention are described below.

[0334] Within the context of the present specification, the term “cut filler” is used to describe to a blend of shredded plant material, such as tobacco plant material, including, in particular, one or more of leaf lamina, processed stems and ribs, homogenised plant material.

[0335] The cut filler suitable to be used with the present invention generally may resemble cut filler used for conventional smoking articles. The cut width of the cut filler preferably may be between 0.3 millimetres and 2.0 millimetres, or between 0.5 millimetres and 1.2 millimetres, or between 0.6 millimetres and 0.9 millimetres.

[0336] Preferably, the strands have a length of between about 10 millimetres and about 40 millimetres before the strands are collated to form the rod of aerosol-generating substrate.

[0337] Preferably, the cut filler is soaked with the aerosol former. Soaking the cut filler can be done by spraying or by other suitable application methods. Preferably, the aerosol former in the cut filler comprisesP408336WQ - 14 January 2026 FTR4090 / PCT - 38 - one or more of glycerol and propylene glycol. The aerosol former may consist of glycerol or propylene glycol or of a combination of glycerol and propylene glycol.

[0338] In other preferred embodiments, the aerosol-generating substrate comprises homogenised plant material, preferably a homogenised tobacco material.

[0339] As used herein, the term “homogenised plant material” encompasses any plant material formed by the agglomeration of particles of plant. For example, sheets or webs of homogenised tobacco material for the aerosol-generating substrates of the present invention may be formed by agglomerating particles of tobacco material obtained by pulverising, grinding or comminuting plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stems. The homogenised plant material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

[0340] The homogenised plant material can be provided in any suitable form.

[0341] In some embodiments, the homogenised plant material may be in the form of one or more sheets. As used herein with reference to the invention, the term “sheet” describes a laminar element having a width and length substantially greater than the thickness thereof.

[0342] The homogenised plant material may be in the form of a plurality of pellets or granules.

[0343] The homogenised plant material may be in the form of a plurality of strands, strips or shreds. As used herein, the term “strand” describes an elongate element of material having a length that is substantially greater than the width and thickness thereof.

[0344] The aerosol former content of the homogenised tobacco material is preferably within the ranges defined above for aerosol-generating substrate having a relatively low aerosol former content.

[0345] In other preferred embodiments, the aerosol-generating substrate is in the form of an aerosolgenerating film comprising a cellulosic based film-forming agent, nicotine and the aerosol former. The aerosol-generating film may further comprise a cellulose based strengthening agent. The aerosolgenerating film may further comprise water, preferably 30 percent by weight of less of water.

[0346] As used herein, the term “film” is used to describe a solid laminar element having a thickness that is less than the width or length thereof. The film may be self-supporting.

[0347] In the context of the present invention the term “cellulose based film-forming agent” is used to describe a cellulosic polymer capable, by itself or in the presence of an auxiliary thickening agent, of forming a continuous film. Preferably, the cellulose based film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methyl cellulose (HEMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and combinations thereof. In particularly preferred embodiments, the cellulose based film-forming agent is HPMC.

[0348] The aerosol former content of the aerosol-generating film is within the ranges defined above for aerosol-generating substrates having a relatively high aerosol former content.

[0349] Suitable aerosol-generating films for use as the aerosol-generating substrate of aerosol-generating articles according to the invention are described in WO-A-2020 / 207733 and WO-A-2022 / 074157.

[0350] Preferably, the aerosol-generating film comprises between 0.5 percent and 10 percent by weight of nicotine, or between 1 percent and 8 percent by weight of nicotine, or between 2 percent and 6 percent by weight of nicotine, on a dry weight basis.

[0351] The aerosol-generating film may be a substantially tobacco-free aerosol-generating film.P408336WQ - 14 January 2026 FTR4090 / PCT - 39 - In alternative embodiments of the invention, the aerosol-generating substrate may comprise a gel composition that includes nicotine, at least one gelling agent and the aerosol former. The gel composition is preferably substantially tobacco free.

[0352] The preferred weight ranges for nicotine in the gel composition are the same as those defined above in relation to aerosol-generating films.

[0353] Suitable gel compositions for use as the aerosol-generating substrate of aerosol-generating articles according to the invention are described in WO-A-2021 / 170642.

[0354] The gel composition preferably comprises at least 50 percent by weight of aerosol former, more preferably at least 60 percent by weight, more preferably at least 70 percent by weight of aerosol former, on a dry weight basis. The gel composition may comprise up to 80 percent by weight of aerosol former. The aerosol former in the gel composition is preferably glycerol.

[0355] In certain embodiments of the invention, the aerosol-generating article further comprises one or more elongate susceptor elements within the rod of aerosol-generating substrate. For example, one or more elongate susceptor elements may be arranged substantially longitudinally within the rod of aerosolgenerating substrate and in thermal contact with the aerosol-generating substrate.

[0356] As used herein with reference to the present invention, the term “susceptor element” refers to a material that can convert electromagnetic energy into heat.

[0357] Suitable susceptor elements for use in the aerosol-generating substrate of aerosol-generating articles according to the present invention are described in WO-A-2021 / 170673.

[0358] Preferably, the rod of aerosol-generating substrate is circumscribed by a wrapper. The wrapper may be a paper wrapper or a non-paper wrapper.

[0359] Suitable paper wrappers for use in specific embodiments of the invention are known in the art and include, but are not limited to: cigarette papers; and filter plug wraps. Suitable non-paper wrappers for use in specific embodiments of the invention are known in the art and include, but are not limited to sheets of homogenised tobacco materials.

[0360] Aerosol-generating articles in accordance with the present invention may form part of an aerosolgenerating system. Such an aerosol-generating system comprises: an aerosol-generating article according to the present invention; and an aerosol-generating device configured to heat the aerosol-generating substrate of the aerosol-generating article.

[0361] The aerosol-generating device comprises means for heating the aerosol-generating substrate to a temperature sufficient to generate an aerosol from the aerosol-generating substrate. Preferably, the aerosol-generating device comprises a housing defining a cavity configured to receive the aerosolgenerating article, and means for heating the aerosol-generating substrate to a temperature sufficient to generate an aerosol from the aerosol-generating substrate when the aerosol-generating article is received within the cavity.

[0362] The aerosol-generating device may be a handheld aerosol-generating device.

[0363] The aerosol-generating device may be an electrically-operated aerosol-generating device.

[0364] The aerosol-generating device may comprise a power supply and control electronics.

[0365] The aerosol-generating device may comprise a battery and control electronics.

[0366] The aerosol-generating device may be configured to heat the aerosol-generating substrate internally. That is, the aerosol-generating device may be configured to supply heat to the aerosolgenerating substrate from a location internal to the aerosol-generating article.P408336WQ - 14 January 2026 FTR4090 / PCT - 40 - For example, in some embodiments the aerosol-generating device comprises a heater element configured to be inserted into the aerosol-generating element when the aerosol-generating article is received within the cavity of the aerosol-generating device.

[0367] In other embodiments, the aerosol-generating article comprises a susceptor element provided at a location within the rod of aerosol-generating substrate, and the aerosol-generating device comprises an inductor coil positioned on or within the housing, a power supply of the aerosol-generating device being connected to the inductor coil and configured to provide a high frequency oscillating current to the inductor coil. This generates an alternating magnetic field that induces a voltage in the susceptor element. The induced voltage causes a current to flow in the susceptor element, and this current causes Joule heating of the susceptor element that, in turn, heats the aerosol-generating substrate. The aerosol-generating device may be capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of between 1 and 5 kilo amperes per metre (kA m), preferably between 2 and 3 kA / m, for example about 2.5 kA / m.

[0368] The aerosol-generating device may be configured to heat the aerosol-generating substrate externally. That is, the aerosol-generating device may be configured to supply heat to the aerosolgenerating substrate from a location external to the aerosol-generating article. For example, in some embodiments the aerosol-generating device comprises a heater element located about a perimeter of the cavity and configured to heat the aerosol-generating substrate of the aerosol-generating article from an exterior of the aerosol-generating element of the aerosol-generating article.

[0369] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0370] Exampleswill now be further described with reference to the drawings of the accompanying Figures in which:

[0371] Figure 1 shows a schematic side sectional view of an aerosol-generating article in accordance with an embodiment of the invention;

[0372] Figure 2 shows a schematic side sectional view of another aerosol-generating article in accordance with another embodiment of the invention;

[0373] Figure 3 shows a schematic side sectional view of another aerosol-generating article in accordance with a further embodiment of the invention;

[0374] Figure 4 shows a schematic side sectional view of another aerosol-generating article in accordance with yet another embodiment of the invention;

[0375] Figure 5 shows a schematic layout of an apparatus for manufacturing a plug element in accordance with an embodiment of the invention;

[0376] Figure 6 shows schematic perspective view of an applicator for applying an additive coating to (a) one surface, and (b) two surfaces, of a paper sheet used in the apparatus of Figure 5;

[0377] Figure 7 shows a comparison of the behaviour of an additive coating applied to a paper sheet in accordance with an aspect of the invention; and

[0378] Figure 8 shows a comparison of the behaviour of another additive coating applied to a paper sheet in accordance with an aspect of the invention.

[0379] DETAILED DESCRIPTIONP408336WQ - 14 January 2026 FTR4090 / PCT - 41 - The aerosol-generating article 1000 shown in Figure 1 comprises an aerosol-generating element 1002 in the form of a substantially cylindrical rod 1004 of shredded tobacco circumscribed by a wrapper 1006. Further, the aerosol-generating article 1000 comprises a substantially cylindrical mouthpiece 1008 comprising a segment 1010 of a cellulosic filtration material circumscribed by a plug wrap 1012.

[0380] The mouthpiece 1008 is attached to the aerosol-generating element 1002 by a band 1014 of tipping paper. Perforations 1016 formed through the tipping paper and the plug wrap are provided to enable admission of ventilation air into the segment 1010 when the consumer draws upon the mouthpiece 1008 during use. The aerosol-generating article 1000 has a length of 70 millimetres and an external diameter of 7.6 millimetres.

[0381] The segment 1010 is in the form of a plug element comprising an embossed sheet of glassine paper. An RTD of the plug element is about 150 millimetres WG.

[0382] The aerosol-generating article 10 shown in Figure 2 comprises a rod 12 of aerosol-generating substrate 12 and a downstream section 14 at a location downstream of the rod 12 of aerosol-generating substrate. Further, the aerosol-generating article 10 comprises an upstream section 16 at a location upstream of the rod 12 of aerosol-generating substrate. Thus, the aerosol-generating article 10 extends from an upstream or distal end 18 to a downstream or mouth end 20, and has an overall length of about 45 millimetres.

[0383] The downstream section 14 comprises a support element 22 located immediately downstream of the rod 12 of aerosol-generating substrate, the support element 22 being in longitudinal alignment with the rod 12. In the embodiment of Figure 2, the upstream end of the support element 18 abuts the downstream end of the rod 12 of aerosol-generating substrate. In addition, the downstream section 14 comprises an aerosol-cooling element 24 located immediately downstream of the support element 22, the aerosol-cooling element 24 being in longitudinal alignment with the rod 12 and the support element 22. In the embodiment of Figure 1 , the upstream end of the aerosol-cooling element 24 abuts the downstream end of the support element 22. In the embodiment of Figure 2, the support element 22 and the aerosol-cooling element 24 together define an intermediate hollow section 50 of the aerosol-generating article 10.

[0384] The support element 22 comprises a first hollow tubular segment 26. The first hollow tubular segment 26 is provided in the form of a hollow cylindrical tube made of filtration material. The first hollow tubular segment 26 defines an internal cavity 28 that extends all the way from an upstream end 30 of the first hollow tubular segment to an downstream end 32 of the first hollow tubular segment 20. The internal cavity 28 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 28.

[0385] The first hollow tubular segment 26 has a length of about 8 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter of about 1.9 millimetres. Thus, a thickness of a peripheral wall of the first hollow tubular segment 26 is about 2.67 millimetres.

[0386] The aerosol-cooling element 24 comprises a second hollow tubular segment 34. The second hollow tubular segment 34 is provided in the form of a hollow cylindrical tube made of filtration material. The second hollow tubular segment 34 defines an internal cavity 36 that extends all the way from an upstream end 38 of the second hollow tubular segment to a downstream end 40 of the second hollow tubular segment 34. The internal cavity 36 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 36.P408336WQ - 14 January 2026 FTR4090 / PCT - 42 - The second hollow tubular segment 34 has a length of about 8 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter of about 3.25 millimetres. Thus, a thickness of a peripheral wall of the second hollow tubular segment 34 is about 2 millimetres. Thus, a ratio between the internal diameter of the first hollow tubular segment 26 and the internal diameter of the second hollow tubular segment 34 is about 0.75.

[0387] The aerosol-generating article 10 comprises a ventilation zone 60 provided at a location along the second hollow tubular segment 34. In more detail, the ventilation zone is provided at about 2 millimetres from the upstream end of the second hollow tubular segment 34. A ventilation level of the aerosolgenerating article 10 is about 25 percent.

[0388] In the embodiment of Figure 2, the downstream section 14 further comprises a mouthpiece element 42 at a location downstream of the intermediate hollow section 50. In more detail, the mouthpiece element 42 is positioned immediately downstream of the aerosol-cooling element 24. As shown in the drawing of Figure 2, an upstream end of the mouthpiece element 42 abuts the downstream end 40 of the aerosolcooling element 18.

[0389] The mouthpiece element 42 is provided in the form of a cylindrical plug element 44 comprising an embossed sheet of glassine paper.

[0390] Optionally, the sheet of glassine paper of the mouthpiece element 42 may include an additive coating, such as an additive coating comprising triacetin, polyethylene glycol, or the like. The additive coating may be on a surface of the sheet, or may be at least partly impregnated into the sheet. The sheet of glassine paper may include a first surface comprising a three-dimensionally patterned surface having an embossed pattern. The patterned surface typically is distributed over an entire surface of the sheet.

[0391] The mouthpiece element 42 has a length of about 12 millimetres and an external diameter of about 7.25 millimetres. An RTD of the mouthpiece element 42 is about 130 millimetres WG.

[0392] The rod 12 comprises an aerosol-generating substrate of one of the types described above. The rod 12 of aerosol-generating substrate has an external diameter of about 7.25 millimetres and a length of about 12 millimetres.

[0393] The aerosol-generating article 10 further comprises an elongate susceptor 46 within the rod 12 of aerosol-generating substrate. In more detail, the susceptor 46 is arranged substantially longitudinally within the aerosol-generating substrate, such as to be approximately parallel to the longitudinal direction of the rod 12. As shown in the drawing of Figure 2, the susceptor 46 is positioned in a radially central position within the rod and extends effectively along the longitudinal axis of the rod 12. In more detail, the susceptor 46 is in thermal contact with the aerosol-generating substrate. The susceptor 46 extends all the way from an upstream end to a downstream end of the rod 12. In effect, the susceptor 46 has substantially the same length as the rod 12 of aerosol-generating substrate.

[0394] In more detail, in the embodiment of Figure 2, the susceptor 46 is provided in the form of a strip and has a length of about 12 millimetres, a thickness of about 60 micrometres, and a width of about 4 millimetres.

[0395] The upstream section 16 comprises an upstream element 48 located immediately upstream of the rod 12 of aerosol-generating substrate, the upstream element 48 being in longitudinal alignment with the rod 12. In the embodiment of Figure 2, the downstream end of the upstream element 48 abuts the upstream end of the rod 12 of aerosol-generating substrate. This advantageously prevents the susceptor 46 fromP408336WQ - 14 January 2026 FTR4090 / PCT - 43 - being dislodged. Further, this ensures that the consumer cannot accidentally contact the heated susceptor 46 after use.

[0396] The upstream element 48 comprises a segment of material 50 in the form of a cylindrical plug of filtration material and a first wrapper 52 circumscribing the segment of material 50. The segment of material 50 has a length of about 5 millimetres. The RTD of the segment of material 50 is about 30 millimetres H2O.

[0397] The aerosol-generating article 10 further comprises a combining wrapper 54 which attaches the upstream element 48 to the remaining components of the aerosol-generating article. In the embodiment of Figure 2 a single combining wrapper 54 is depicted, which circumscribes and holds together the upstream element 48, the rod 12, and the downstream section 14 to form the aerosol-generating article.

[0398] However, it will be clear that alternative configurations are possible, wherein two or more combining wrappers are employed to assemble the different components of the aerosol-generating article. For example, a first combining wrapper could be used to attach the support element 22 to the aerosol-cooling element 24, and the resulting assembly could then be attached by means of a second combining wrapper to the upstream section 16 and the rod 12. The resulting combination of components could then be attached to the mouthpiece element 42 by means of a tipping wrapper. As shown in the drawing of Figure 1 , the aerosol-generating article 10 further comprises a wrapper 70 circumscribing the rod 12 of aerosolgenerating substrate. The wrapper 70 is separate and distinct from the first wrapper 52 circumscribing the segment of material 50. Neither one of the first wrapper 52 and the wrapper 70 comprises a metallic foil.

[0399] In the aerosol-generating article 10 of Figure 2, one or more of the first hollow tubular segment 26 of the support element 22, the second hollow tubular segment 34 of the aerosol-cooling element 24, and the segment of material 50 of the upstream element 48 may be made of the same material according to the present invention used in the mouthpiece element 42.

[0400] The aerosol-generating article 100 shown in Figure 3 comprises a rod of aerosol-generating substrate 112 and a downstream section 114 at a location downstream of the rod 112 of aerosol-generating substrate. Additionally, the aerosol-generating article 100 comprises an upstream section 116. Thus, the aerosol-generating article 100 extends from an upstream or distal end 118 - which substantially coincides with an upstream end of the upstream section 116 - to a downstream or mouth end 120, which coincides with a downstream end of the downstream section 114. The downstream section 114 comprises a hollow tubular element 122 and a mouthpiece element 150. The upstream section 116 comprises an upstream plug element 124.

[0401] The aerosol-generating article 100 has an overall length of about 45 millimetres and an outer diameter of about 7.2 mm.

[0402] The rod of aerosol-generating substrate 112 comprises a shredded tobacco material. The rod of aerosol-generating substrate 112 comprises 150 milligrams of a shredded tobacco material comprising from 13 percent by weight to 16 percent by weight of glycerine. The density of the aerosol-generating substrate is about 300 mg per cubic centimetre. The RTD of the rod of aerosol-generating substrate 112 is between about 6 to 8 mm H2O. The rod of aerosol-generating substrate 112 is individually wrapped by a plug wrap (not shown).

[0403] The hollow tubular element 122 is located immediately downstream of the rod 112 of aerosolgenerating substrate, the hollow tubular element 122 being in longitudinal alignment with the rod 112. The upstream end of the hollow tubular element 122 abuts the downstream end of the rod 112 of aerosolgenerating substrate.P408336WQ - 14 January 2026 FTR4090 / PCT .. 44 ..

[0404] The hollow tubular element 122 defines a hollow section of the aerosol-generating article 110. The hollow tubular element 122 does not substantially contribute to the overall RTD of the aerosol-generating article. In more detail, an RTD of the hollow tubular element 122 is about 0 mm H2O.

[0405] As shown in Figure 3, the hollow tubular element 122 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular element 122 defines an internal cavity that extends all the way from an upstream end of the hollow tubular element 122 to a downstream end of the hollow tubular element 122. The internal cavity is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity.

[0406] The hollow tubular element 122 has a length of about 21 millimetres, an external diameter of about 7.2 millimetres, and an internal diameter of about 6.7 millimetres. Thus, a thickness of a peripheral wall of the hollow tubular element 122 is about 0.25 millimetres.

[0407] The aerosol-generating article 100 comprises a ventilation zone 160 provided at a location along the hollow tubular element 122. The ventilation zone 160 comprises a circumferential row of openings or perforations circumscribing the hollow tubular element 122. The perforations of the ventilation zone 160 extend through the wall of the hollow tubular element 122, in order to allow fluid ingress into the internal cavity from the exterior of the article 100. A ventilation level of the aerosol-generating article 10 is about 16 percent.

[0408] On top of a rod 112 of aerosol-generating substrate and a downstream section 114 at a location downstream of the rod 112, the aerosol-generating article 100 comprises an upstream section 140 at a location upstream of the rod 112. As such, the aerosol-generating article 10 extends from a distal end 116 substantially coinciding with an upstream end of the upstream section 140 to a mouth end or downstream end 118 substantially coinciding with a downstream end of the downstream section 114.

[0409] As described briefly above, the upstream section 116 comprises an upstream plug element 124 located immediately upstream of the rod 112 of aerosol-generating substrate, the upstream plug element 124 being in longitudinal alignment with the rod 112. The downstream end of the upstream plug element 124 abuts the upstream end of the rod 112 of aerosol-generating substrate. The upstream plug element 124 is provided in the form of a hollow cylindrical plug of filtration material having a wall thickness of about 1 mm and defining an upstream internal cavity. The upstream element 124 has a length of about 5 millimetres. An external diameter of the upstream plug element 124 is about 7.1 mm. An internal diameter of the upstream plug element 42 is about 5.1 mm.

[0410] The mouthpiece element 150 extends from the downstream end of the hollow tubular element 122 to the downstream or mouth end of the aerosol-generating article 100. The mouthpiece element 150 has a length of about 7 mm. An external diameter of the mouthpiece element 150 is about 7.2 mm.

[0411] The mouthpiece element 150 is provided in the form of a cylindrical plug element comprising an embossed sheet of glassine paper. An RTD of the mouthpiece element 150 is about 60 millimetres WG.

[0412] In the aerosol-generating article 100 of Figure 3, the plug element 124 of the upstream section 116 may be made of the same material according to the present invention used in the mouthpiece element 150.

[0413] Optionally, a sheet of glassine paper of the mouthpiece element 150, or of the plug element 124, may include an additive coating, such as an additive coating comprising triacetin, polyethylene glycol, or the like. The additive coating may be on a surface of the sheet, or may be at least partly impregnated into the sheet. The sheet of glassine paper may include a first surface comprising a three-dimensionallyP408336WQ - 14 January 2026 FTR4090 / PCT - 45 - patterned surface having an embossed pattern. The patterned surface typically is distributed over an entire surface of the sheet.

[0414] The aerosol-generating article 510 shown in Figure 4 comprises a rod 512 of aerosol-generating substrate and a downstream section 514 at a location downstream of the rod 512 of aerosol-generating substrate. Thus, the aerosol-generating article 10 extends from an upstream or distal end 518 to a downstream or mouth end 520, and has an overall length of about 45 millimetres.

[0415] The downstream section 514 comprises a support element 522 located immediately downstream of the rod 512 of aerosol-generating substrate, the support element 522 being in longitudinal alignment with the rod 512. In the embodiment of Figure 4, an upstream end of the support element 522 abuts the downstream end of the rod 512 of aerosol-generating substrate. In addition, the downstream section 514 comprises an aerosol-cooling element 524 located immediately downstream of the support element 522, the aerosol-cooling element 524 being in longitudinal alignment with the rod 512 and the support element 522. In the embodiment of Figure 4, the upstream end of the aerosol-cooling element 524 abuts the downstream end of the support element 522. The downstream section 514 further comprises a mouthpiece filter 550 located immediately downstream of the aerosol-cooling element 524, the mouthpiece filter 550 being in longitudinal alignment with the rod 512, the support element 522 and the aerosol-cooling element 524. In the embodiment of Figure 4, the upstream end of the mouthpiece filter 550 abuts the downstream end of the aerosol-cooling element 524.

[0416] The support element 522 comprises a hollow tubular segment 526. The hollow tubular segment 526 is provided in the form of a hollow cylindrical tube made of filtration material. The hollow tubular segment 526 defines an internal cavity 528 that extends all the way from an upstream end of the first hollow tubular segment to a downstream end of the hollow tubular segment 520. The internal cavity 528 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 528.

[0417] The hollow tubular segment 526 has a length of about 8 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter of about 1 .9 millimetres. Thus, a thickness of a peripheral wall of the hollow tubular segment 526 is about 2.67 millimetres.

[0418] The aerosol-cooling element 524 is formed from a sheet 534 of glassine paper having a thickness of 50 micrometres ± 2 micrometres. The sheet 534 of glassine paper has been crimped and gathered to define a plurality of channels that extend along the length of the aerosol-cooling element 524. The total surface area of the aerosol-cooling element 524 is between 8000 square millimetres and 9000 square millimetres, which is equivalent to approximately 500 square millimetres per millimetre of length of the aerosol-cooling element 524. The specific surface area of the aerosol-cooling element 524 is approximately 2.5 square millimetres / milligram. A porosity of the aerosol-cooling element 524 in the longitudinal direction is between 60 percent and 90 percent. The crimped and gathered sheet 534 of glassine paper is wrapped within a filter paper wrapper 536 to form the aerosol-cooling element 524. The filter paper wrapper 536 may be made of glassine paper.

[0419] The mouthpiece filter 550 extends from the downstream end of the hollow tubular element 526 to the downstream or mouth end of the aerosol-generating article 510. The mouthpiece filter 550 has a length of about 12 mm. An external diameter of the mouthpiece filter 550 is about 7.2 mm.

[0420] The mouthpiece filter 550 is provided in the form of a cylindrical plug element comprising an embossed sheet of glassine paper. An RTD of the mouthpiece filter 550 is about 102 millimetres WG.P408336WQ - 14 January 2026 FTR4090 / PCT - 46 - The rod 512, the support element 522, the aerosol-cooling element 524 and the mouthpiece 550 are assembled by being tightly wrapped within a paper wrapper 570. The interference between the paper wrapper 570 and each of the elements described above locates the elements and defines the structure of the aerosol-generating article 10.

[0421] Optionally, a sheet of glassine paper of the mouthpiece element 550, or of the aerosol-cooling element 524, may include an additive coating, such as an additive coating comprising triacetin, polyethylene glycol, or the like. The additive coating may be on a surface of the sheet, or may be at least partly impregnated into the sheet. The sheet of glassine paper may include a first surface comprising a three-dimensionally patterned surface having an embossed pattern. The patterned surface typically is distributed over an entire surface of the sheet.

[0422] Referring now to Fig. 5, 6a) and 6b), there is shown apparatus 299 for forming plug elements from a sheet of paper material. The apparatus 299 includes means to apply an additive coating to the sheet of paper material. The apparatus 299 is particular useful for treating a sheet of glassine paper to form a three-dimensionally patterned surface on one more surfaces of the sheet, and then impregnating the patterned surface or surfaces with the additive coating.

[0423] Referring particularly, to Fig. 5, there is shown two additional processes into the conventional paper filter rod manufacturing line, namely: applying an embossed pattern to the sheet of glassine paper (marked “a”); and dispersing droplets comprising an additive coating onto the patterned surface (marked “b”), as shown in more detail in Figures 6a) and 6b)). In the example, dispersing includes spraying the droplets onto the glassine paper.

[0424] A glassine paper bobbin 231 unwinds a continuous reel of glassine paper 101 , that is guided into an embossing unit comprising a first embossing roll 241 and a second embossing roll 242. The embossing rolls 241 , 242 are arranged to define a nip gap between them, through which the glassine paper 101 is directed. As the paper passes through this nip gap, the mechanical compression action of the rolls imparts a predetermined three-dimensionally patterned surface structure to the sheet, thereby rearranging the cellulosic fibres at the surface and producing the embossed glassine paper 120. An schematic example patterned surface 121 is shown in Figure 6a) It should be noted that the geometry of the embossed features shown in Figure 6a) is exemplary and not intended to be limiting. A range of suitable geometries, dimensions, and arrangements of embossing features may be employed within the scope of the present innovation to achieve the desired structural modification and functional performance of the embossed glassine paper. The selection of embossing geometry may be optimized based on factors such as additive absorption efficiency, paper rigidity, and compatibility with downstream processing.

[0425] The resulting embossed glassine paper 120 exhibits increased surface roughness and porosity relative to the unmodified glassine paper 101 , thereby enabling improved absorption and retention of subsequently applied liquid additives. The degree of embossing may be controlled by adjusting roll pressure, nip gap, roll surface pattern, and processing speed, allowing reproducible modification of the paper’s surface structure while maintaining its rigidity and low intrinsic filtration characteristics.

[0426] Following embossing, the embossed glassine paper 120 may be used immediately in the element forming apparatus 299, or may be wound onto a reel forstorage or transportation to another factory location, prior to further processing such as additive coating application and filter rod formation.

[0427] The embossing unit produces an embossed glassine paper 120, the surface of which contains three-dimensionally patterned surface that rearrange the cellulosic fibres of the glassine paper 101. ThisP408336WQ - 14 January 2026 FTR4090 / PCT - 47 - process step (a) is positioned directly after the paper unwinding stage and before rod formation, thereby enabling surface modification at an early stage in the production line.

[0428] Following embossing, the now embossed glassine paper 120 passes to an additive applicator 245, as shown in Figure 6a), where the dispersing step (b) occurs. Here, a liquid phase comprising an additive coating 248, for example, triacetin or a mixture of polyethylene glycol and triacetin, is uniformly applied to the patterned surface. The additive applicator includes a reservoir 246 of the liquid phase upstream of a pressurised nozzle 247 to control dispersal.

[0429] It will be noted that the additive applicator 245 may include a single reservoir 246 and nozzle 247, or may include any suitable assembly comprising a series of reservoirs and I or nozzles. Furthermore, the additive applicator 245 may be configured to apply the liquid phase comprising the additive coating 248 to only a first surface of the embossed glassine paper 120, as shown in Fig. 6a), or may be configured to apply the liquid phase comprising the additive coating 248 to both the first surface and an opposing, second surface of the embossed glassine paper 120, as shown in Fig. 6b).

[0430] The three-dimensionally patterned structure of the embossed glassine paper 120 allows the droplets to impregnate and be retained within the paper volume. This is in contrast to the unmodified glassine paper 101 , where liquids remain on the surface and slide off.

[0431] The dispersing step is positioned between the embossing unit and the forming funnel 250, ensuring that the additive coating is applied immediately after embossing and before the paper is rolled into the cylindrical filter structure.

[0432] Once sprayed, the treated embossed glassine paper 235 is directed into the forming funnel 250, where it is shaped into a continuous cylindrical rod. A paper overwrap 210, from a continuous reel of paper overwrap 211 , is applied to enclose the rod, and the assembly is passed through a heating block 260 to secure dimensional stability. The rolling stage 265 and subsequent advancement via the garniture belt 270, driven by the garniture belt drive system 271 , 272, complete the rod formation process. The continuous rod is then cut into segments to produce individual paper-based plug elements.

[0433] The inclusion of steps (a) and (b) within the production line provides a novel means of enabling liquid additives to be efficiently impregnated and retained in glassine paper while maintaining the structural rigidity and low filtration properties required for paper-based plug elements.

[0434] Referring now to Figures 7 and 8, there are shown comparative examples from laboratory tests to evaluate the effectiveness of the three-dimensionally patterned surfaces in enhancing the absorption and retention of additive coatings on glassine paper. Two sheets of glassine paper (Glassine 33) were prepared: one unmodified glassine paper 101 and one embossed glassine paper 120 that was subjected to the embossing process as described herein.

[0435] Additive solutions were applied to each paper 101 , 120 using a pipette.

[0436] In Figure 7 there is shown the results of applying a triacetin solution 248a to samples of glassine paper 101 , 120. On the unmodified glassine paper 101 , the triacetin solution 248a remained on a surface of the paper 101 , and slid off when the paper was inclined, demonstrating the limited liquid absorption capacity and hydrophobic nature of the glassine paper 101. In contrast, the embossed glassine paper 120 immediately absorbed the triacetin solution 248a, and the resulting stain remained fixed even when the paper was tilted. This demonstrates that the embossing process effectively modifies the surface structure to facilitate rapid impregnation and retention of the additive.P408336WQ - 14 January 2026 FTR4090 / PCT - 48 - In Figure 8, there is shown the results of applying a solution 248b comprising a mixture of polyethylene glycol and triacetin in a 70:30 ratio. Again, on the unmodified glassine paper 101 , the droplet remained on the surface and was prone to run off the surface when tilted. On the embossed glassine paper 120, the mixture rapidly impregnated the sheet and was retained within the embossed features.

[0437] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

[0438] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting items. Any one or more of the features of these items may be combined with any one or more features of another item, embodiment, or aspect described herein.

[0439] Item 1. A plug element for use in an aerosol-generating article, the plug element comprising a cellulosic filtration material comprising a sheet of paper material, wherein the sheet of paper material is embossed or debossed and wherein an RTD of the plug element is at least 0.8 millimetres WG per unit length.

[0440] Item 2. A plug element according to Item 1 , wherein the paper material is a processed paper material selected from glassine paper, parchment paper, and natural greaseproof paper.

[0441] Item 3. A plug element according to Item 1 or Item 2, wherein the sheet of paper material has a density of at least 0.85 grams / cubic centimetre.

[0442] Item 4. A plug element according to any one of the preceding Items, wherein the sheet of paper material has a grammage of at least 40 gsm.

[0443] Item 5. A plug element according to any one of the preceding Items, wherein the sheet of paper material has a grammage of less than or equal to 60 gsm.

[0444] Item 6. A plug element according to any one of the preceding Items, wherein the sheet of paper material has a width of less than 300 millimetres.

[0445] Item 7. A plug element according to any one of the preceding Items, wherein the embossed or debossed sheet of paper material comprises an embossed or debossed pattern which is regularly spaced and distributed across the entire sheet surface.P408336WQ - 14 January 2026 FTR4090 / PCT - 49 - Item 8. A plug element according to any one of the preceding Items, wherein the cellulosic filtration material further comprising an additive coating applied to the sheet of paper material, the additive coating comprising at least 5 percent by weight of an additive for reducing phenols.

[0446] Item 9. A plug element according to any one of the preceding Items, wherein the plug element is substantially free from cellulose acetate.

[0447] Item 10. An aerosol-generating article comprising:

[0448] a rod of aerosol-generating substrate;

[0449] a downstream section located downstream of the rod of aerosol-generating substrate; wherein the downstream section comprises a downstream element in axial alignment with the rod of aerosol-generating substrate, the downstream element comprising a plug element according to any one of Items 1 to 9.

[0450] Item 11. An aerosol-generating article according to Item 10, wherein the downstream section further comprises a hollow tubular element abutting a downstream end of the rod of aerosolgenerating substrate, the downstream element located downstream of the hollow tubular element.

[0451] Item 12. An aerosol-generating article according to Item 10 or Item 11 , wherein the downstream element is a mouthpiece filter segment comprising the plug element and a filter wrapper circumscribing the plug element.

[0452] Item 13. A method of manufacturing a plug element for use in an aerosol-generating article, the method comprising:

[0453] providing a sheet of paper material;

[0454] embossing or debossing the sheet of paper material to form an embossed or debossed sheet of paper material;

[0455] gathering the embossed or debossed sheet of paper material to form a continuous rod of cellulosic filtration material;

[0456] cutting the continuous rod of cellulosic filtration material into a plurality of plug elements; wherein the step of gathering the embossed or debossed sheet of paper material is carried out immediately after the step of embossing or debossing the sheet of paper material.

[0457] Item 14. A method according to Item 13, wherein an RTD of each plug element of the plurality of plug elements is at least 0.8 millimetres WG per unit length, and an RTD coefficient of variation determined for the plurality of plug elements is less than 5.

[0458] Item 15. A plug element for use in an aerosol-generating article, the plug element comprising a cellulosic filtration material comprising a sheet of paper material, wherein the plug element is obtainable by a method comprising the steps of:

[0459] providing a sheet of paper material;P408336WQ - 14 January 2026 FTR4090 / PCT - 50 - embossing or debossing the sheet of paper material to form an embossed or debossed sheet of paper material;

[0460] gathering the embossed or debossed sheet of paper material to form a continuous rod of cellulosic filtration material;

[0461] cutting the continuous rod of cellulosic filtration material into a plurality of plug elements; wherein the step of gathering the embossed or debossed sheet of paper material is carried out immediately after the step of embossing or debossing the sheet of paper material.

Claims

P408336WQ - 14 January 2026 FTR4090 / PCT - 51 - CLAIMS1. A plug element of an of an aerosol-generating article, the plug element comprising:a cellulosic filtration material comprising a sheet of glassine paper, wherein the sheet comprises:a first surface comprising a first three-dimensionally patterned surface, and an additive coating at least partly impregnated into the sheet.

2. The plug element of claim 1 , the sheet comprising the first surface and an opposing, second surface, and wherein the second surface comprises a second three-dimensionally patterned surface.

3. The plug element of claim 1 or claim 2, wherein the, or each, three-dimensionally patterned surface comprises one or both of: a debossed pattern or an embossed pattern.

4. The plug element of any one of claims 1 to 3, wherein the, or each, three-dimensionally patterned surface is a regular, repeating pattern.

5. The plug element of any one of claims 1 to 4, wherein the, or each, three-dimensionally patterned surface is distributed over an entire surface of the sheet.

6. The plug element of any one of claims 1 to 5, wherein the additive coating comprises at least one of triacetin or polyethylene glycol.

7. The plug element of any one of claims 1 to 6, wherein the additive coating comprises a mixture of triacetin and polyethylene glycol and, optionally, wherein the mixture comprises a ratio of polyethylene glycol : triacetin of around 70: 30.

8. The plug element of any one of claims 1 to 7, wherein the sheet is configured to operably define one or more airflow channels extending through the plug element.

9. An aerosol-generating article comprising:a rod of aerosol-generating substrate;a downstream section located downstream of the rod of aerosol-generating substrate; wherein the downstream section comprises a downstream element in axial alignment with the rod of aerosol-generating substrate, the downstream element comprising a plug element according to any one of claims 1 to 8.

10. An aerosol-generating article according to claim 9, wherein the downstream section further comprises a hollow tubular element abutting a downstream end of the rod of aerosol-generating substrate, the downstream element located downstream of the hollow tubular element.

11. An aerosol-generating article according to claim 9 or 10, wherein the downstream element is a mouthpiece filter segment comprising the plug element and a filter wrapper circumscribing the plug element.P408336WQ - 14 January 2026 FTR4090 / PCT - 52 -12. A method of manufacturing a plug element for an aerosol-generating article, the method comprising:providing cellulosic filtration material comprising a sheet of glassine paper;treating the sheet to form a first three-dimensionally patterned surface on a first surface of the sheet; andat least partly impregnating the first surface with an additive coating.

13. The method according to claim 12, wherein treating the sheet comprises applying one or both of an embossed pattern ora debossed pattern.

14. The method according to claim 12 or 13, wherein at least partly impregnating the first surface comprises dispersing droplets onto the sheet, wherein the droplets comprise a liquid phase comprising the additive coating.

15. A plug element for use in an aerosol-generating article, the plug element comprising a cellulosic filtration material comprising a sheet of glassine paper, wherein the sheet is obtainable by a method comprising the steps of:providing cellulosic filtration material comprising a sheet of glassine paper;treating the sheet to form a first three-dimensionally patterned surface on a first surface of the sheet; andat least partly impregnating the first surface with an additive coating.

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