Aerosol generation article

Abstract

To provide an aerosol-forming substrate equipped with a slender susceptor.SOLUTION: An aerosol generation article (10) is provided with a plurality of elements which are assembled into a rod shape having an end (70) on a mouth side and a distal end (80) upstream of the end on the mouth side. The plurality of elements are provided with an aerosol-forming substrate (20) provided with a slender susceptor (25) arranged in the aerosol-forming substrate in a long axis direction. A plug element (90) is positioned upstream of the aerosol-forming substrate in the rod and adjacent to the same. The plug elements (90) thereby prevent direct physical contact with a distal end of the slender susceptor (25) arranged in a longitudinal axial direction in the aerosol-forming substrate (20).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-forming substrate and an elongate susceptor disposed within the aerosol-forming substrate. In particular, the present invention relates to an inductively heatable aerosol-generating article.

Background Art

[0002] From the prior art, inductively heatable aerosol-generating articles comprising an aerosol-forming substrate and an elongate susceptor disposed within the aerosol-forming substrate are well known. For example, International Patent Publication WO 2015 / 176898 discloses an aerosol-generating article having an elongate susceptor disposed within an aerosol-forming substrate plug. The aerosol-generating article comprises a plurality of elements in the form of rods and is adapted to be used in an electrically operated aerosol-generating device comprising an inductor for generating heat within the elongate susceptor. The position of the elongate susceptor may depend on the method of manufacturing the aerosol-forming substrate comprising the susceptor. However, the elongate susceptor typically extends at least to the distal end of the aerosol-forming substrate plug. This exposed position of at least the end of the susceptor can change the consistency of the article as the position of the susceptor can change during handling or transportation of the article.

[0003] Accordingly, it would be desirable to have an aerosol-generating article comprising an aerosol-forming substrate and an elongate susceptor disposed within the aerosol-forming substrate that improves the consistency of the article.

Summary of the Invention

[0004] According to the present invention, there is provided an aerosol-generating article comprising a plurality of elements assembled in the form of a rod having a mouth-side end and a distal end upstream from the mouth-side end. The plurality of elements comprises an aerosol-forming substrate having an elongate susceptor disposed longitudinally within the aerosol-forming substrate. A plug element is located upstream of and adjacent to the aerosol-forming substrate within the rod. The plug element prevents direct physical contact with the distal end of the elongate susceptor disposed longitudinally within the aerosol-forming substrate.

[0005] The plug element prevents direct contact with the distal end of the susceptor and can thus prevent displacement or deformation of the susceptor during handling or transportation of the article. The susceptor, typically a metal component and relatively heavy, has a tendency to become detached from the aerosol-forming substrate during transportation of the article. Thus, the plug element also prevents the susceptor from falling out of the aerosol-generating article, for example if the susceptor becomes detached during transportation of the article. A further advantage of the plug element in protecting the distal end of the aerosol-forming substrate may relate to aesthetic or branding reasons. The plug element can be used to cover the distal end of the article. This can result in an aesthetically pleasing appearance at the distal end of the article. Also, information regarding, for example, the brand, contents, flavor, or electronically actuated device used with the article can be provided on the article.

[0006] The plug element can fix the form and position of the susceptor within the aerosol-forming substrate and can thus improve or guarantee the consistency from article to article. In addition, the plug element also preferably improves the aesthetic appearance of the article and can provide an easy way to provide further information about the article to the user.

[0007] As used herein, the terms "upstream" and "downstream" are used to describe the relative position of an element of an aerosol-generating article, or a portion of an element, in relation to the direction in which a user inhales on the aerosol-generating article during use. The aerosol-generating article is in the form of a rod that includes two ends, a mouth-side end (i.e., the proximal end through which aerosol exits the aerosol-generating article and is delivered to the user) and a distal end. During use, a user can inhale at the mouth-side end. Also, the distal end may be referred to as the upstream end and is upstream of the mouth-side end.

[0008] The aerosol-generating article is preferably a smoking article that generates an aerosol. Further, the aerosol-generating article is preferably a smoking article that generates a nicotine-containing aerosol.

[0009] The plug element may be a porous element. The porous plug element preferably does not change the draw resistance of the aerosol-generating article. The plug element preferably has a porosity of at least 50 percent in the longitudinal axis direction of the rod. The plug element preferably has a porosity of 50 percent to 90 percent. The porosity in the longitudinal axis direction of the plug element is defined by the ratio of the cross-sectional area of the material forming the plug element at the position of the plug element to the internal cross-sectional area of the aerosol-generating article. This definition of porosity is also suitably applicable to any other element of the aerosol-generating article.

[0010] The plug element may be made of a porous material or may comprise a plurality of openings. This can be achieved, for example, by laser perforation.

[0011] The permeability of the plug element may enable a user to draw air through the rod via the plug element.

[0012] The plurality of openings are preferably distributed homogeneously across the cross-section of the plug element.

[0013] The aperture sizes of the plurality of apertures are preferably sized such that the distal end of the aerosol-forming substrate cannot be seen from above.

[0014] The porosity or permeability of the plug element can be varied to correspond to the control of the draw resistance through the aerosol-generating article.

[0015] The draw resistance (RTD) of the plug element may be from 20 mmWG to 40 mmWG, preferably from 25 mmWG to 35 mmWG (millimeter water gauge). The RTD of the plug element preferably does not exceed 30 mmWG. The draw resistance (RTD) of the plug element is preferably from 1 to 5 mmWG per millimeter of the length of the plug element, for example 2.5 mmWG per millimeter of the length of the plug element. The plug element can have the same RTD as an element made of an aerosol-forming substrate comprising an elongate susceptor.

[0016] Alternatively, the plug element may be airtight and may be formed of a material that is impermeable to air. In such embodiments, the article can be configured such that air flows into the rod through the sidewalls, for example through holes defined within cigarette paper or a wrapper material.

[0017] The plug element can be made of any material suitable for use in an aerosol-generating article for an inductively heatable aerosol-generating device. The plug element can be made of, for example, the same material as that used in the article, such as that used in a conventional mouthpiece filter, that used in an aerosol cooling element, or that used in a support element. Exemplary materials are filter materials, ceramics, polymeric materials, cellulose acetate, cardboard, non-inductively heatable metals, zeolites, or an aerosol-forming substrate.

[0018] The plug element is preferably made of a heat-resistant material. The heat-resistant material for the plug element means herein that the plug element can withstand temperatures up to about 350 °C. Thereby, it is preferred that the plug element is not affected by the heated susceptor or the heated aerosol-forming substrate.

[0019] During use of the article, it is preferred that the consistency, geometry or optical properties of the plug element do not change.

[0020] During use of the article, it is preferred that the plug element does not generate additional substances with respect to the generated aerosol.

[0021] The plug element has a diameter approximately equal to the diameter of the aerosol-generating article. The plug element preferably has a diameter of 5 millimeters to 10 millimeters. The diameter of the plug is preferably greater than 5 mm, for example 6 mm to 8 mm. The plug element can have a length defined as a dimension along the longitudinal axis of the aerosol-generating article. The length of the plug element can be 1 millimeter to 10 millimeters, for example 4 mm to 8 mm or 5 mm to 7 mm. The plug element is preferably substantially cylindrical. The plug element is preferably less than 8 mm. The plug element preferably has a length of at least 2 millimeters, preferably at least 3 millimeters, or at least 5 millimeters, in order to facilitate the assembly of the aerosol-generating article.

[0022] In principle, whenever a value is stated throughout this specification, it is understood that the value is explicitly disclosed. However, it is also understood that the value may not be a precisely specific value for technical considerations.

[0023] The plug element may be a separate element. The above-mentioned minimum size of the length of the plug element facilitates or enables the use of a conventional combiner for assembling a plurality of elements in a rod shape.

[0024] The plug element may have a homogeneous structure. The plug element may, for example, have a homogeneous texture and appearance. The plug element may, for example, have a continuous regular surface over its entire cross-section or, for example, have no recognizable symmetry. It is preferable that at least the distal end of the plug element has a homogeneous structure. The homogeneous distal end of the plug element advantageously contributes to the consistency of the plug element over the entire cross-section of the article.

[0025] The plug element may comprise an inner surface defining a recess, which is preferably located at least at the proximal end of the plug element. The recess is directed towards the aerosol-forming substrate. The recess is arranged within the plug element such that the plug element does not contact or only contacts the elongate susceptor on a limited area when the plug element is disposed within the aerosol-forming substrate. The recess may be arranged centrally within the plug element such that the central portion of the proximal end of the plug element does not contact the elongate susceptor. The inner surface of the recess may have, for example, a concave shape, for example a dome shape. The diameter of the recess in the radial direction of the rod is preferably larger than the radial extension of the elongate susceptor.

[0026] Providing a recess within the plug element such that the plug element does not physically contact the susceptor and generally limiting the contact area between the plug element and the aerosol-forming substrate can prevent excessive heating of the plug element (especially those parts of the plug element that contact the susceptor). This reduces the risk of overheating or carbonization of the plug element and can also broaden the options for materials suitable for the manufacture of the plug element.

[0027] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may comprise a tobacco-containing material comprising volatile tobacco flavor compounds released from the substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may further comprise an aerosol-forming agent. Examples of suitable aerosol-forming agents are glycerin and propylene glycol.

[0028] When the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may comprise one or more of tobacco leaves, tobacco leaves, fragments of tobacco stems, reconstituted tobacco, homogenized tobacco, extruded tobacco and expanded tobacco, and may for example comprise one or more of powders, granules, pellets, fragments, spaghetti-like threads, flakes or sheets. The solid aerosol-forming substrate may be in a form not contained in a container, or a suitable container or cartridge may be provided. For example, the aerosol-forming material of the solid aerosol-forming substrate may be contained within paper or other wrapper and may have the form of a plug. When in the form of a plug wrapped with the aerosol-forming substrate, the entire plug including any wrapper is considered to be the aerosol-forming substrate.

[0029] Optionally, the solid aerosol-forming substrate may contain additional tobacco or non-tobacco volatile flavor compounds released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain, for example, capsules containing additional tobacco or non-tobacco volatile flavor compounds, and such capsules may melt during heating of the solid aerosol-forming substrate.

[0030] The aerosol-forming substrate may comprise one or more homogenized tobacco material sheets that are gathered in a rod shape, surrounded by a wrapper, and cut to provide individual plugs of the aerosol-forming substrate. The aerosol-forming substrate preferably comprises an assembly of crimped sheets of homogenized tobacco material.

[0031] The aerosol-forming tobacco substrate preferably comprises a tobacco material, fibers, a binder, and an aerosol former, and is preferably a crimped tobacco sheet. The tobacco sheet is preferably a cast leaf. A cast leaf is a form of reconstituted tobacco formed from a slurry comprising tobacco particles, fiber particles, an aerosol former, a binder, and also flavors for example.

[0032] The wrapper can be any suitable non-tobacco material for wrapping the elements of the aerosol-generating article in the form of a rod. The wrapper holds a plurality of elements within the aerosol-generating article when the article is assembled onto the rod.

[0033] The aerosol-forming substrate can have a substantially cylindrical shape. The aerosol-forming substrate can be substantially elongated. The aerosol-forming substrate can also have a length and a circumference that is substantially orthogonal to this length.

[0034] Furthermore, the length of the aerosol-forming substrate can be 10 millimeters. As another method, the length of the aerosol-forming substrate can be 12 millimeters. Furthermore, the diameter of the aerosol-forming substrate can be from 5 millimeters to 12 millimeters.

[0035] As used herein, the term " susceptor " means a material capable of converting electromagnetic energy into heat. Eddy currents induced within the susceptor cause heating of the susceptor when it is positioned within a varying electromagnetic field. Since the elongated susceptor is in a position in thermal contact with the aerosol-forming substrate, the aerosol-forming substrate is heated by the susceptor. The susceptor has a length dimension that is greater than its width dimension or its thickness dimension, for example a length dimension that is twice its width dimension or its thickness dimension. Thus, the susceptor can be depicted as an elongated susceptor. The susceptor is arranged substantially in the longitudinal direction within the rod. This means that the length dimension of the elongated susceptor is aligned substantially parallel to the longitudinal axis of the rod, for example within ± 10 degrees parallel to the longitudinal axis of the rod. In a preferred embodiment, the elongated susceptor may be positioned at a radially central position within the rod and extends along the longitudinal axis of the rod.

[0036] The susceptor is preferably in the form of pins, rods, strips or blades. The susceptor preferably has a length of 5 millimeters to 15 millimeters, for example 6 mm to 12 mm, or 8 mm to 10 mm. The susceptor preferably has a width of 1 mm to 5 mm and may have a thickness of 0.01 mm to 2 mm, for example a thickness of 0.5 mm to 2 mm. In a preferred embodiment, the susceptor may have a thickness of 10 micrometers to 500 micrometers, but more preferably is 10 to 100 micrometers. When the susceptor has a constant cross-section, for example a circular cross-section, it has a preferred width or diameter of 1 millimeter to 5 millimeters. When the susceptor has the form of a strip or blade, the width of the strip or blade is preferably 2 millimeters to 8 millimeters, more preferably 3 millimeters to 5 millimeters, for example 4 millimeters, and the thickness is preferably 0.03 millimeters to 0.15 millimeters, more preferably 0.05 millimeters to 0.09 millimeters, for example 0.07 millimeters and preferably has a rectangular shape.

[0037] The elongated susceptor preferably has a length that is the same as or shorter than the length of the aerosol-forming substrate. The elongated susceptor preferably has the same length as the aerosol-forming substrate.

[0038] The susceptor can be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptors include metal or carbon. Preferred susceptors may include ferromagnetic materials such as ferromagnetic alloys, ferrite iron, or ferromagnetic steel, or stainless steel, or may consist of such ferromagnetic materials. A suitable susceptor may be aluminum or may include aluminum. Preferred susceptors can be formed from 400 series stainless steels such as grade 410, or grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when positioned within an electromagnetic field having similar values of frequency and magnetic field strength. Thus, any of the parameters of the susceptor, such as the type, length, width, and thickness of the material, can be varied to provide the desired power dissipation within a known electromagnetic field.

[0039] Preferred susceptors may be heated to temperatures in excess of 250 °C. Suitable susceptors may comprise a non-metallic core with a metal strip disposed on the surface of a ceramic core, for example. The susceptor may have a protective outer layer enclosing the susceptor, such as a protective ceramic layer or a protective glass layer. The susceptor may comprise a protective coating formed of glass, ceramic, or an inert metal, formed over the core of the susceptor material.

[0040] The susceptor is arranged in thermal contact with the aerosol-forming substrate. Thus, as the temperature of the susceptor increases, the aerosol-forming substrate is heated and an aerosol is formed. The susceptor is preferably arranged in physical direct contact with the aerosol-forming substrate, for example within the aerosol-forming substrate.

[0041] The susceptor may be a multi-material susceptor and may include a first susceptor material and a second susceptor material. The first susceptor material is laminated in physical contact with the second susceptor material. The second susceptor material preferably has a Curie temperature lower than 500°C. The first susceptor material is preferably mainly used to heat the susceptor when the susceptor is placed in an oscillating electromagnetic field. Any suitable material may be used. For example, the first susceptor material may be aluminum or an iron material such as stainless steel. The second susceptor material is preferably mainly used to indicate when the susceptor reaches a specific temperature (that temperature which is the Curie temperature of the second susceptor material). The Curie temperature of the second susceptor material can be used to regulate the temperature of the entire susceptor during operation. Therefore, the Curie temperature of the second susceptor material needs to be below the ignition point of the aerosol-forming substrate. Suitable materials for the second susceptor material may include nickel and certain nickel alloys.

[0042] By providing a susceptor having at least first and second susceptor materials, either a second susceptor material having a Curie temperature and a first susceptor material not having a Curie temperature, or first and second susceptor materials having different first and second Curie temperatures, heating of the aerosol-forming substrate and temperature control of the heating can be separated. The first susceptor material is preferably a magnetic material having a Curie temperature exceeding 500 °C. From the viewpoint of heating efficiency, it is desirable that the Curie temperature of the first susceptor material exceeds any maximum temperature at which the susceptor can be heated. The second Curie temperature can be preferably selected to be lower than 400 °C, preferably lower than 380 °C, or lower than 360 °C. The second susceptor material is preferably a magnetic material selected to have a second Curie temperature substantially the same as the desired maximum heating temperature. That is, its second Curie temperature is preferably substantially the same as the temperature to which the susceptor should be heated to generate an aerosol from the aerosol-forming substrate. Its second Curie temperature can be, for example, in the range of 200 °C to 400 °C, or 250 °C to 360 °C. The second Curie temperature of the second susceptor material can be selected such that, for example, when heated by a susceptor at a temperature equal to its second Curie temperature, the overall average temperature of the aerosol-forming substrate does not exceed 240 °C.

[0043] The aerosol-generating article can have a substantially cylindrical shape. The aerosol-generating article can be substantially elongated. The aerosol-generating article can also have a length and a circumference substantially orthogonal to the length.

[0044] The overall length of the aerosol-generating article can be from 30 millimeters to 100 millimeters. In a preferred embodiment, the overall length of the aerosol-generating article is 40 mm to 55 mm, for example 47 to 53 millimeters.

[0045] The outer diameter of the aerosol-generating article can be from 5 millimeters to 12 millimeters, for example 6 mm to 8 mm. In one preferred embodiment, the aerosol-generating article has an outer diameter of 7.2 mm ± 10 percent.

[0046] The aerosol-generating article may comprise a mouthpiece element. The mouthpiece element may be located at the mouth-side or downstream end of the aerosol-generating article.

[0047] The mouthpiece element may comprise at least one filter segment. The filter segment may be a cellulose acetate filter plug made of cellulose acetate tow. The filter segment may have a low particle filtration efficiency or a very low particle filtration efficiency. The filter segment may be axially spaced from the aerosol-forming substrate. The filter segment is 7 millimeters in length in one embodiment, but may have a length of 5 millimeters to 14 millimeters.

[0048] The mouthpiece element is the last part in the downstream direction of the aerosol-generating article. The user contacts the mouthpiece element to pass the aerosol generated by the aerosol-generating article through the mouthpiece element and send it to the user. Thus, the mouthpiece element is disposed downstream of the aerosol-forming substrate.

[0049] The mouthpiece element preferably has an outer diameter substantially equal to the outer diameter of the aerosol-generating article. The mouthpiece element may have an outer diameter of 5 millimeters to 10 millimeters, for example, an outer diameter of 6 millimeters to 8 millimeters. In a preferred embodiment, the mouthpiece element has an outer diameter of 7.2 mm ± 10 percent. The mouthpiece element may have a length of 5 millimeters to 25 millimeters, preferably a length of 10 millimeters to 17 millimeters. In a preferred embodiment, the mouthpiece element has a length of 12 mm to 14 mm. In a preferred embodiment, the mouthpiece element has a length of 7 mm.

[0050] The aerosol-generating article may be located immediately downstream of the aerosol-forming substrate and may comprise a support element that can be adjacent to the aerosol-forming substrate.

[0051] The support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of cellulose acetate, cardboard, crumpled paper (such as crumpled heat-resistant paper or crumpled sulfuric acid paper), and polymer materials (such as low-density polyethylene (LDPE)). In a preferred embodiment, the support element is formed from cellulose acetate.

[0052] The support element may include a hollow tubular element. In a preferred embodiment, the support element comprises a hollow cellulose acetate tube.

[0053] The support element preferably has an outer diameter substantially equal to the outer diameter of the aerosol-generating article.

[0054] The support element may have an outer diameter of 5 millimeters to 12 millimeters, for example an outer diameter of 5 mm to 10 mm or 6 mm to 8 mm. In a preferred embodiment, the support element has an outer diameter of 7.2 mm ± 10 percent. The support element may have a length of 5 millimeters to 15 millimeters. In a preferred embodiment, the support element has a length of 8 mm.

[0055] The aerosol-generating article may comprise an aerosol cooling element. The aerosol cooling element can be located downstream of the aerosol-forming substrate. For example, the aerosol cooling element can be located immediately downstream of the support element and can be adjacent to the support element.

[0056] The aerosol cooling element may be located between the support element and a mouthpiece element located at the extreme downstream end of the aerosol-generating article.

[0057] As used herein, the term "aerosol cooling element" is used to describe an element having a large surface area and a low draw resistance. In use, the aerosol formed by the volatile compounds released from the aerosol-forming substrate is drawn through the aerosol cooling element before being conveyed to the mouth-side end of the aerosol-generating article. In contrast to a filter with a high draw resistance (e.g., a filter formed from a bundle of fibers), the aerosol cooling element has a low draw resistance. Chambers and recesses within the aerosol-generating article, such as expansion chambers and support elements, are not considered to be aerosol cooling elements.

[0058] The aerosol cooling element preferably has a longitudinal porosity of more than 50 percent. The airflow path through the aerosol cooling element is preferably relatively unconstrained. The aerosol cooling element may be an assembly of sheets or an assembly of crimped sheets. The aerosol cooling element may comprise a sheet material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil, or any combination thereof.

[0059] In a preferred embodiment, the aerosol cooling element comprises an assembly of biodegradable material sheets. For example, an assembly of non-porous paper sheets, or an assembly of sheets of biodegradable polymer materials such as polylactic acid or grades of Mater-Bi® (a commercial family of starch-based copolyesters).

[0060] The aerosol cooling element preferably includes an assembly of PLA sheets, and more preferably an assembly of crimped PLA sheets. The aerosol cooling element may be formed from sheets having a thickness of 10 micrometers to 250 micrometers (e.g., 50 micrometers). The aerosol cooling element may be formed from an assembly of sheets having a width of 150 millimeters to 250 millimeters. The aerosol cooling element may have a specific surface area of 300 square millimeters to 1000 square millimeters per millimeter of length and 10 square millimeters to 100 square millimeters per milligram of weight. In some embodiments, the aerosol cooling element may be formed from an assembly of material sheets having a specific surface area of about 35 square millimeters per milligram of weight. The aerosol cooling element may have an outer diameter of 5 millimeters to 10 millimeters, e.g., 7 millimeters.

[0061] In some preferred embodiments, the length of the aerosol cooling element is 10 millimeters to 15 millimeters. Preferably, the length of the aerosol cooling element is 10 millimeters to 14 millimeters, e.g., 13 millimeters.

[0062] In an alternative embodiment, the length of the aerosol cooling element is 15 millimeters to 25 millimeters. Preferably, the length of the aerosol cooling element is 16 millimeters to 20 millimeters, e.g., 18 millimeters.

[0063] As the aerosol passes through the aerosol cooling element, the temperature of the aerosol decreases due to the transfer of thermal energy to the aerosol cooling element. Moreover, the water droplets liquefied from the aerosol may adsorb to the material of the aerosol cooling element. Depending on the type of material forming the aerosol cooling element, the water content of the aerosol may be reduced by 0 to 90 percent. For example, when the aerosol cooling element contains polylactic acid, the water content is not reduced much. For example, when a starch-based material (such as Mater-Bi, etc.) is used to form the aerosol cooling element, the reduction of water can be about 40 percent. Therefore, by selecting the material that makes up the aerosol cooling element, the water content in the aerosol can be determined.

[0064] For example, an aerosol formed by heating a tobacco-derived aerosol-forming substrate typically contains phenolic compounds. The aerosol cooling element can reduce the levels of phenol and cresol by 90 percent to 95 percent.

[0065] Commercially available electronic heating devices are designed to use aerosol-generating articles of a predetermined dimension, particularly a predetermined standard length. In order to make the aerosol-generating article usable with these standard heating devices, the overall length of the aerosol-generating article should be the standard length. Typically, such a standard length is 45 millimeters. Furthermore, the dimensions and arrangement of the aerosol-forming substrate provided within the aerosol-generating article and heated by the heating element of the heating device preferably remain unchanged.

[0066] Therefore, when a plug element is added to the aerosol-generating device, the length of the article increases by the length of the plug element. Therefore, the length of the plug element should not exceed 8 mm so that the overall length of the aerosol-generating article is not excessively extended. An aerosol-generating article having a standard length of 45 mm preferably becomes an article having a length of 47 mm to 53 mm when the plug element is provided.

[0067] However, the length of the article may be kept constant by compensating for the added length of the plug element through shortening of another element or segment of the article (preferably an aerosol cooling element). However, it is preferred that doing so does not change the characteristics of the article.

[0068] In multiple experiments, it has been shown that in aerosol-generating articles of standard length, an aerosol cooling element having a length shorter than the standard 18 millimeter aerosol cooling element can achieve the desired aerosol cooling or reduction of phenolic compounds. In particular, in shorter aerosol cooling elements made of polylactic acid, comparable cooling or different smoke chemical properties have been found.

[0069] Accordingly, the additional length of the plug element is compensated for by shortening of the aerosol cooling element. Shortening of the aerosol cooling element, or further shortening of the aerosol cooling element, may also be made by providing a hollow tube.

[0070] Some of the materials used in aerosol-generating articles are also more affected by cost than other materials. For example, the materials used for the aerosol cooling element, in particular the crimped polylactic acid sheet, are expensive. Thus, in aerosol-generating articles, the length of the aerosol cooling element may be reduced compared to such elements within a standard aerosol-generating article for an electronic device. Typically, the standard length of the aerosol cooling element is 18 millimeters. To maintain the overall length of the aerosol-generating article at a predetermined length (e.g., 45 millimeters), the length of the mouthpiece element may be extended to compensate for the shorter length of the aerosol cooling element.

[0071] Surprisingly, it has been found that the aerosol cooling element can be shortened to some extent without adversely affecting the chemical properties of the smoke. This has also surprisingly been found to be achievable without changing the movement of the smoke components through the mouthpiece when the length differences are compensated within the mouthpiece. In particular, when a hollow tube is used for compensating the overall length, no change in the smoke components due to the mouthpiece has been detected. It has been found that a shortening of just a few millimeters of the aerosol cooling element leads to significant cost savings. The extension of the mouthpiece is preferably achieved by providing a hollow tube. The hollow tube (e.g., a cardboard tube) can sometimes be manufactured at very low cost, and as a result, cost savings can be achieved by partially "replacing" the aerosol cooling element in the tobacco part of the aerosol generating article with a hollow tube in the mouthpiece part of the aerosol generating article.

[0072] Accordingly, the mouthpiece element may comprise a hollow tube.

[0073] The hollow tube, if present, is preferably arranged at the downstream end of the mouthpiece element and thus at the downstream end of the aerosol generating article. This gives the effect of the recessed filter to the aerosol generating article. In this way, when using an e-cigarette system, a tactile sensation equivalent to that obtained with the smoking of a conventional cigarette provided with a recessed filter can be provided to the customer.

[0074] The hollow tube of the mouthpiece element may be made of cardboard. The hollow tube may also be made of different materials (e.g., paper or thin plastic sheet material). The hollow tube preferably has a stability that allows for the handling of the aerosol generating article.

[0075] The length of the hollow tube may be from 3 millimeters to 8 millimeters. The length of the hollow tube is preferably 5 millimeters.

[0076] The length of the above-mentioned hollow tube, particularly the length of the cardboard tube, has been found to enable good production of the tube and good handling of the tube during the assembly of the mouthpiece element and the aerosol-generating article.

[0077] The wall thickness of the hollow tube is preferably from 100 micrometers to 300 micrometers, for example 200 micrometers. When inserting the aerosol-generating article into the electronic heating device, the consumer typically holds or presses the aerosol-generating article at its proximal end. Since the hollow tube is preferably the most proximal segment of the aerosol-generating article, the aerosol-generating article is thus typically pushed by the hollow tube. It has been found that the above-mentioned wall thickness meets the stability requirements for the hollow tube, particularly the cardboard tube, when the aerosol-generating article is inserted into the electronic heating device.

[0078] The aerosol-generating article according to the present invention preferably comprises a plug element, an aerosol-forming substrate comprising a susceptor, a support element, an aerosol cooling element and a mouthpiece element. The mouthpiece element comprises at least one filter element and may optionally comprise a hollow tube. In such an aerosol-generating article, the support element is arranged downstream of the aerosol-forming substrate and the aerosol cooling element is arranged downstream of the support element.

[0079] In the aerosol-generating article according to the present invention, comprising a mouthpiece element comprising a filter segment and a hollow tube, the hollow tube is preferably arranged at the distal end of the rod. The length of the mouthpiece element, preferably the length of the hollow tube, can be extended, particularly by adding or extending the hollow tube, to compensate for the shortened length of the aerosol cooling element so that the overall length of the aerosol-generating article is maintained at a predetermined overall length. The overall length of the article is preferably 45 millimeters and the length of the aerosol cooling element of the tobacco element is at most 15 millimeters. The length of the mouthpiece element, preferably the length of the hollow tube, is adapted according to the length of the aerosol cooling element so that the overall length of the aerosol-generating article is maintained at a predetermined overall length.

[0080] The possibility of having a shortened aerosol cooling element, the compensation for such a shortened aerosol cooling element by providing an additional hollow tube into the mouthpiece element, its advantages and specific features are described in detail in European Patent Application No. 15173224.5. That application, and its content regarding the compensation of the above-mentioned length, are incorporated herein by reference.

[0081] The aerosol generating article preferably comprises five to six elements or segments.

[0082] Elements of the aerosol forming article, such as the aerosol forming substrate, the plug element and any other optional elements of the aerosol generating article (such as the support element, the aerosol cooling element, and the mouthpiece element), are surrounded by an outer wrapper. The outer wrapper may be formed from any suitable material or combination of materials. The outer wrapper is preferably cigarette paper.

[0083] The present invention will be further described with reference to embodiments, which are illustrated by the following drawings. Brief Description of the Drawings

[0084]

Figure 1

Figure 2

Figure 3

Figure 4

[0085] Figure 1 illustrates an aerosol generating article 10. The aerosol generating article 10 includes five coaxially aligned elements: a plug element 90, an aerosol forming substrate 20, a support element 30, an aerosol cooling element 40, and a mouthpiece 50. Each of these five elements is a substantially cylindrical element, and each has a substantially the same diameter. These five elements are arranged in series and surrounded by an outer wrapper 60 to form a cylindrical rod. A blade-shaped susceptor 25 is located within and in contact with the aerosol forming substrate. The susceptor 25 has a length substantially the same as that of the aerosol forming substrate and is positioned along the radial central axis of the aerosol forming substrate.

[0086] The susceptor 25 is a ferrite iron material having a length of 10 mm, a width of 3 mm, and a thickness of 1 mm. One or both ends of the susceptor may be sharpened or pointed to facilitate insertion into the aerosol forming substrate.

[0087] The aerosol generating article 10 has a proximal or mouth-side end 70, which the user inserts into their mouth during use, and a distal end 80, which is located at the opposite end of the aerosol generating article 10 relative to the mouth-side end 70. The overall length of the assembled aerosol generating article 10 is approximately 47 mm to 53 mm, and the diameter is approximately 7.2 mm.

[0088] During use, air is drawn by the user through the aerosol generating article from the distal end 80 to the mouth-side end 70. Also, the distal end 80 of the aerosol generating article may be described as the upstream end of the aerosol generating article 10, and the mouth-side end 70 of the aerosol generating article 10 may also be described as the downstream end of the aerosol generating article 10. The elements of the aerosol generating article 10 located between the mouth-side end 70 and the distal end 80 may be described as being upstream of the mouth-side end 70 or, alternatively, as being downstream of the distal end 80.

[0089] The plug element 90 is located at the distal or upstream end 80 of the aerosol-generating article 10. In FIG. 1, the plug element is shown as a hollow tube, for example a hollow cellulose acetate tube. The inner diameter of the hollow tube is the same as or slightly smaller than the width of the susceptor 25 in order to prevent the susceptor from disengaging from the distal end of the aerosol-forming substrate 20.

[0090] The aerosol-forming substrate 20 is located immediately downstream of the plug element 90 within the aerosol-generating article 10. In FIG. 1, the aerosol-forming substrate 20 comprises an assembly of crimped and homogenized tobacco material sheets surrounded by a wrapper. The crimped sheets of homogenized tobacco material contain glycerin as an aerosol former.

[0091] The support element 30 is located immediately downstream of the aerosol-forming substrate 20 and adjacent to the aerosol-forming substrate 20. In FIG. 1, the support element 30 is a hollow cellulose acetate tube. The support element 30 positions the aerosol-forming substrate 20 within the aerosol-generating article 10. Thus, the support element 30 serves to prevent the aerosol-forming substrate 20 from being pushed downstream towards the aerosol cooling element 40 within the aerosol-generating article 10, for example when inserting the article into a device. The support element 30 also acts as a spacer to space the aerosol cooling element 40 of the aerosol-generating article 10 from the aerosol-forming substrate 20.

[0092] The aerosol cooling element 40 is located immediately downstream of the support element 30 and adjacent to the support element 30. In use, the volatile substances released from the aerosol-forming substrate 20 pass along the aerosol cooling element 40 towards the mouth-side end 70 of the aerosol-generating article 10. The volatile substances cool within the aerosol cooling element 40 and may form an aerosol for the user to inhale. In FIG. 1, the aerosol cooling element comprises an assembly of crimped sheets of polylactic acid surrounded by a wrapper 90. The assembly of crimped sheets of polylactic acid defines a plurality of longitudinally extending paths along the length of the aerosol cooling element 40.

[0093] The mouthpiece 50 is located immediately downstream of, and adjacent to, the aerosol cooling element 40. In FIG. 1, the mouthpiece 50 includes a conventional cellulose acetate tow filter with low filtration efficiency.

[0094] To assemble the aerosol generating article 10, the five cylindrical elements described above are aligned and closely wrapped within an outer wrapper 60. In FIG. 1, the outer wrapper is a conventional cigarette rolling paper.

[0095] When the article is manufactured, four of the elements, excluding the plug element 90, can be assembled. Next, the susceptor 25 is inserted into the distal end 80 of the assembly so as to penetrate the aerosol forming substrate 20. Next, the plug element 80 is aligned with the assembly, and then the five elements are wrapped with the wrapper 60 to form the complete aerosol generating article 10. As another method of assembly, the susceptor 25 is inserted into the aerosol forming substrate 20 before assembling the plurality of elements to form a rod.

[0096] The aerosol generating article 10 of FIG. 1 is designed to engage with an electrically operated aerosol generating device that includes an induction coil (or inductor) for smoking or consumption by a user.

[0097] FIG. 2 illustrates an aerosol generating article 1 having six elements, where the same or similar elements are designated with the same reference numerals. The plug element 91, the aerosol forming substrate 20, a support element in the form of a hollow cellulose acetate tube 30, the aerosol cooling element 40, the mouthpiece filter 50 and the cardboard tube 56 are arranged continuously and coaxially, and are assembled by cigarette rolling paper and tipping paper (not shown) to form a rod. The cardboard tube 56 is located at the mouth end 70 of the aerosol generating article 1, and the plug element 91 is located at the distal end 80 of the aerosol generating article 1.

[0098] When assembled, the rod has a length 15 of, for example, 45 millimeters and an outer diameter of about 7.2 millimeters.

[0099] The plug element 91 is a porous plug, for example a plug of heat-resistant material with open pores. The plug element has a length 95 of 3 to 5 mm.

[0100] The aerosol-forming substrate 20 may include a bundle of crimped cast leaf tobacco wrapped in filter paper (not shown) to form a plug. The cast leaf tobacco includes an additive containing glycerin as an aerosol-forming additive. The length 25 of the aerosol-forming substrate is 12 millimeters. The length of the susceptor 25 is about 10 mm and is pointed at its proximal end.

[0101] The hollow acetate tube 30 is located immediately downstream of and adjacent to the aerosol-forming substrate 20. The length 35 of the acetate tube 30 is 8 mm.

[0102] The aerosol cooling element 40 has a length 45 of 10 mm to 13 mm and an outer diameter of about 7.12 mm. The aerosol cooling element 40 is preferably formed from a sheet of polylactic acid having a thickness of 50 mm ± 2 mm. The sheet of polylactic acid is curled and assembled to define a plurality of channels extending along the length of the aerosol cooling element 40. The total surface area of the aerosol cooling element is 300 square millimeters to 1000 square millimeters per 1 mm of the length of the aerosol cooling element 40, or about 10 square millimeters to 100 square millimeters per 1 mg of the weight of the aerosol cooling element 40.

[0103] The length 45 of the aerosol cooling element 40 is 5 mm to 8 mm shorter than that of a conventional aerosol cooling element of an aerosol-generating article having a standard length of 45 mm. The length of such a conventional aerosol cooling element of an aerosol-generating article of standard length, particularly an aerosol cooling element made of a polylactic acid sheet, is 18 mm.

[0104] The mouthpiece filter 50 disposed downstream of the aerosol cooling element 40 may be a conventional mouthpiece filter formed from cellulose acetate and has a length 55 of 7 millimeters.

[0105] The cardboard tube 56 is the most downstream element of the aerosol generating article 1 and also has a length 57 of 3 - 5 millimeters. The cardboard tube, together with the plug element 80, compensates for the shorter aerosol cooling element 50 so that the overall length of the aerosol generating article is 45 mm. The cardboard tube 56 also provides a recessed mouth-side end 70 of the aerosol generating article, mimicking the use of a conventional cigarette with a recessed mouth-side end.

[0106] The shortened length of the aerosol cooling element 40 can compensate for the additional length 95 of the plug element 91 alone. The cardboard tube 56 may optionally be provided.

[0107] In Figure 3, the plug element 92 comprises a recess 920 with an open end directed towards the aerosol forming substrate 20. The recess 920 is dome-shaped and has a maximum depth 921 corresponding to 25% - 50% of the length 95 of the plug element. When the plug element has a length 95 of 5 mm, the depth 921 of the recess 920 is approximately 1 mm - 2.5 mm. The material of the plug element 92 is a heat-resistant material that can withstand a temperature of about 350°C. The plug element is preferably porous to allow air to pass through the plug element 92.

[0108] Figure 4 illustrates an embodiment of a plug element 93 having an opening 930 disposed longitudinally within the plug element for air to pass through. The material of the plug element may be airtight in another way. The opening 930 has an irregular star-shaped cross-section, which can serve the purpose of marking and contribute to the aesthetic appearance of the aerosol generating article.

Claims

1. An aerosol-generating article comprising a plurality of elements assembled in the form of a rod having a mouth end and a distal end upstream from the mouth end, wherein the plurality of elements comprises an aerosol-forming substrate comprising an elongate susceptor disposed longitudinally within the aerosol-forming substrate, a plug element being located upstream of and adjacent to the aerosol-forming substrate within the rod, the plug element preventing direct physical contact with the distal end of the elongate susceptor disposed longitudinally within the aerosol-forming substrate.

2. The aerosol-generating article according to claim 1, wherein the plug element has a draw resistance (RTD) of 20 mmWG to 40 mmWG.

3. The aerosol-generating article according to any one of claims 1 to 2, wherein the plug element comprises a plurality of openings.

4. The aerosol-generating article according to any one of claims 1 to 3, wherein the plug element is made of ceramic, a polymeric material, cellulose acetate, cardboard, a non-inductively heatable metal, zeolite, or an aerosol-forming substrate.

5. The aerosol-generating article according to claim 1, wherein the plug element is airtight.

6. The aerosol-generating article according to any one of claims 1 to 5, wherein at least the distal end of the plug element has a homogeneous structure.

7. The aerosol-generating article according to any one of claims 1 to 6, wherein the plug element comprises an inner surface defining a recess, the recess being disposed within the plug element so that the proximal end of the plug element does not contact the elongate susceptor disposed within the aerosol-forming substrate.

8. The aerosol-generating article according to claim 7, wherein the inner surface of the recess has a concave shape.

9. The aerosol-generating article according to any one of claims 1 to 8, wherein the plug element is made of a heat-resistant material.

10. The aerosol-generating article according to any one of claims 1 to 9, wherein the plug element is a separate element.

11. The aerosol-generating article according to any one of claims 1 to 10, wherein the plug element has a length of 1 millimeter to 10 millimeters.

12. The aerosol-generating article according to any one of claims 1 to 9, wherein the plug element is a coating applied to the distal end of the aerosol-generating substrate.

13. The aerosol-generating article according to any one of claims 1 to 12, comprising an assembly of sheets of a homogenized tobacco material as the aerosol-forming substrate.

14. The plurality of elements further comprises a support element, an aerosol cooling element, and a mouthpiece element comprising a filter segment and a hollow tube, the aerosol cooling element of the tobacco element having a length of at most 15 millimeters, and the length of the mouthpiece element being adapted according to the length of the aerosol cooling element such that the overall length of the aerosol-generating article is maintained at a predetermined overall length. The aerosol-generating article according to any one of claims 1 to 13.

15. The hollow tube provided in the mouthpiece element is disposed at the distal end of the rod, and the length of the hollow tube is adapted according to the length of the aerosol cooling element such that the overall length of the aerosol-generating article is maintained at a predetermined overall length. The aerosol-generating article according to claim 14.

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