Aerosol-generating article with laminated wrapper

Abstract

To provide an aerosol-generating article including an aerosol-forming substrate and a laminated wrapper.SOLUTION: The aerosol-forming substrate contains a plant material cut filler. The plant material cut filler contains a plant lamina of at least 25 percent based on the total weight of the plant material. The aerosol-forming substrate further contains an aerosol-former of about 6 percent to about 20 percent. The laminated wrapper is at least partly wrapped around the aerosol-forming substrate. The laminated wrapper comprises a heat conductive layer and a heat insulating layer. The heat conductive layer and the heat insulating layer overlap along an axial direction of the aerosol-generating article.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an aerosol-generating article, an aerosol-generating device, and a method for producing an aerosol-generating article. [Background technology]

[0002] It is known to provide an aerosol-generating device for generating an inhalable aerosol. Such a device may heat an aerosol-forming substrate contained in an aerosol-generating article without burning the aerosol-forming substrate. The aerosol-generating article may have a rod shape for inserting the aerosol-generating article into a heating chamber of the aerosol-generating device. A heating element may be disposed in or around the heating chamber for heating the aerosol-forming substrate after the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device.

[0003] Although the temperatures required for such devices to release a reasonable amount of material to allow the formation of an acceptable aerosol are significantly lower than combustion, not all substrates are suitable for releasing a sufficient amount of material to form a suitable aerosol at a given temperature below the combustion temperature of the aerosol-forming substrate. Thus, sophisticated aerosol-forming substrates have been developed to allow the release of material at low temperatures. Today, this is accomplished by converting tobacco leaves into artificial homogenized tobacco sheets, for example using papermaking or casting processes.

[0004] However, to allow for acceptable aerosol generation at temperatures below combustion, relatively large amounts of aerosol former are often used, and typically the lower the temperature, the more aerosol former is required The presence of large amounts of aerosol former can result in unintended consequences, particularly contamination of the wrapper of the aerosol-generating article.

[0005] It is therefore desirable to provide an aerosol generating article that has a simple structure and allows for aerosol generation at low temperatures. It is further desirable to provide so-called "heat-and-no-burn" articles that have a more natural appearance and taste. Summary of the Invention

[0006] According to a first aspect of the present invention, there is provided an aerosol-generating article comprising an aerosol-forming substrate and a laminated wrapper. The aerosol-forming substrate comprises a cut plant material filler, the cut plant material filler comprising at least 25 percent plant lamina per total weight of the plant material, and the aerosol-forming substrate further comprises about 6 percent to about 20 percent aerosol formers. The laminated wrapper is at least partially wrapped around the aerosol-forming substrate. The laminated wrapper comprises a thermally conductive layer and a thermally insulating layer. The thermally conductive layer and the thermally insulating layer overlap along an axial direction of the aerosol-generating article.

[0007] Advantageously, by using natural plant material lamina, a more natural taste and appearance of the aerosol-generating article may be achieved. The term "lamina" refers to the leaf blade portion of a plant without a stem.

[0008] The aerosol-forming substrate preferably comprises cut filler. In this document, "cut filler" is used to refer to blends of finely cut plant material, particularly leaf lamina, processed stems and ribs, homogenized plant material, such as those made into sheet form using a casting or papermaking process. The cut filler may also comprise other post-cut filler tobacco or casings. According to a preferred embodiment of the present invention, the cut filler comprises at least 25 percent of plant leaf lamina, more preferably at least 50 percent of plant leaf lamina, even more preferably at least 75 percent of plant leaf lamina, and most preferably at least 90 percent of plant leaf lamina. The plant material is preferably one of tobacco, mint, tea, and clove, although the present invention is preferably equally applicable to other plant materials having the ability to release a substance upon application of heat that can then form an aerosol.

[0009] The tobacco plant material preferably includes one or more lamina of bright tobacco, dark tobacco, aromatic tobacco, and filler tobacco. Bright tobacco is a tobacco that generally has large, light-colored leaves. Throughout this specification, the term "bright tobacco" is used for flue-cured tobacco. Examples of bright tobacco include Chinese flue-cured tobacco, Brazilian flue-cured tobacco, American flue-cured tobacco (such as Virginia tobacco), Indian flue-cured tobacco, Tanzanian flue-cured tobacco, or other African flue-cured tobacco. Bright tobacco is characterized by a high sugar-to-nitrogen ratio. From a sensory perspective, bright tobacco is a tobacco type with a spicy and lively sensation after curing. According to the present invention, bright tobacco is tobacco having a reducing sugar content of about 2.5 percent to about 20 percent based on dry weight of the leaf and a total ammonia content of less than about 0.12 percent based on dry weight of the leaf. Reducing sugars include, for example, glucose or fructose. Total ammonia includes, for example, ammonia and ammonia salts. Dark tobacco is tobacco that generally has large, dark leaves. Throughout this specification, the term "dark tobacco" is used for air-cured tobacco. In addition, dark tobacco may be fermented. Tobacco that is primarily used for chewing tobacco, snuff, cigar tobacco, and pipe blends are also included in this category. Typically, these dark tobaccos are air-cured and may be fermented. From a sensory perspective, dark tobacco is a tobacco type with a smoky, dark cigar-type sensation after curing. Dark tobacco is characterized by a low sugar-to-nitrogen ratio. Examples for dark tobacco are Burley Malawi or other African Burley, dry cured dark Brazilian Galpao, sun cured or air cured Indonesian Kasturi.According to the present invention, dark tobacco is tobacco with a reducing sugar content of less than about 5 percent based on dry weight of the leaf and a total ammonia content of up to about 0.5 percent based on dry weight of the leaf. Aromatic tobacco is tobacco with small, often light-colored leaves. Throughout this specification, the term "aromatic tobacco" is used in contrast to other tobaccos with high aromatic content, such as essential oils. From a sensory perspective, aromatic tobacco is a tobacco type with a spicy and aromatic sensation after curing. Examples of aromatic tobacco are Greek Orient, Orient Turkey, semi-orient tobacco but flame-cured, US Burley such as Perique, Rustica, US Burley or Maryland. Filler tobacco is not a specific tobacco type, but includes tobacco types that are used in blends and are primarily used to complement other tobacco types that do not bring a specific characteristic aroma direction to the final product. Examples of filler tobacco are the stem, midrib, or petiole of other tobacco types. A specific example can be flue-dried lower petiole stems from Brazil.

[0010] However, in order to use a large amount of natural leaves for the cut filler, a large amount of aerosol former is required, especially at low temperatures. According to the present invention, a special wrapper is provided that prevents the appearance of stains due to high aerosol former content. In particular, it has been found that thermally conductive materials, such as metals, prevent the appearance of stains very well. In that regard, it has been found that stains can be advantageously prevented regardless of the orientation of the thermally conductive layer relative to the aerosol-forming substrate, i.e., whether the thermally conductive layer faces towards the aerosol-forming substrate or whether the thermally conductive layer faces away from the aerosol-forming substrate.

[0011] Moreover, it has been found, advantageously, that the thermally conductive layer may beneficially contribute to the energy distribution within the aerosol-generating article. By providing the laminate wrapper with a thermally conductive layer, uniform heating of the aerosol-forming substrate of the aerosol-generating article may be achieved. In this regard, the aerosol-generating article may be used together with an aerosol-generating device, which will be described in more detail below. The aerosol-generating device may comprise a heating element for heating the aerosol-forming substrate of the aerosol-generating article. The heating element radiates heat for this purpose. By providing the laminate wrapper with a thermally conductive layer, the heat radiated by the heating element may be uniformly distributed throughout the laminate wrapper. Since the laminate wrapper is at least partially disposed around the aerosol-forming substrate, the thermally conductive layer may aid in uniform heating of the aerosol-generating substrate.

[0012] The thermal insulation layer may prevent heat leakage from the aerosol-forming substrate to the surroundings of the aerosol-generating article. Additionally, the thermal insulation layer may provide structural stability to the laminate wrapper. The thermal insulation layer may act as a support for the thermal insulation layer.

[0013] The combination of a thermally conductive layer and a thermally insulating layer is particularly useful for heating the aerosol-forming substrate from within the aerosol-generating article, for example with a pin or blade. According to the present invention, the thermally conductive layer and the thermally insulating layer overlap along the axial direction of the aerosol-generating article. The axial direction is along the longitudinal axis of the aerosol-generating article. Typically, the aerosol-generating article may have a rod shape. In this case, the axial direction is along the extension of the rod. The term "overlapping" means that at least a portion of the laminate wrapper comprises a thermally conductive layer disposed adjacent to the thermally insulating layer in the radial direction, and at least a different portion of the laminate wrapper comprises only a thermally conductive layer or only a thermally insulating layer in the radial direction. In other words, at least a portion of the laminate wrapper comprises only a thermally conductive layer or only a thermally insulating layer, and at least a different portion of the laminate wrapper comprises both a thermally conductive layer and a thermally insulating layer. In yet another words, a portion of the thermally conductive layer is not covered by or does not cover the thermally insulating layer, or both.

[0014] Advantageously, the present invention can be useful in forming aerosols in a number of different configurations: - When the heat source is within the aerosol-generating article (e.g. a heated blade or pin) with the metal layer facing towards the aerosol-generating substrate. In such a configuration, the thermally conductive layer can absorb some of the heat radiated from the heat source and heat the aerosol-generating substrate in its vicinity. This can produce a smooth average temperature across the aerosol-generating substrate. - When the heat source is within the aerosol-generating article (e.g. a heated blade or pin) and the metal layer faces towards the aerosol-generating substrate. Due to the high aerosol former content, the aerosol former is likely to soak the insulating layer, especially if made of paper, cotton, glass fibre, viscose or other similar materials. This can then create a wicking effect as the thermally conductive layer heats up and vaporises the aerosol former which is drawn towards the thermally conductive layer. - the heat source is on the outside of the aerosol-generating article, with the metal layer facing towards the aerosol-generating substrate. In this configuration, the thermally conductive layer can still absorb heat from the heat source and radiate it directly to the aerosol-forming substrate in contact with the thermally conductive layer. Thus, compared to the embodiment in which no thermally conductive layer is present, the heat is concentrated closer to the aerosol-forming substrate and must be transmitted from the heat source to the article, possibly through a corresponding paper wrapper. - When the heat source is on the outside of the aerosol-generating article and the metal layer faces towards the aerosol-generating substrate: This structure may have the same advantages as wicking as described above, but has the added advantage that transfer from the heat source to the thermally conductive layer is less likely to be interrupted.

[0015] At least a portion of the laminate wrapper preferably includes a thermally conductive layer. This portion of the laminate wrapper may be used for heating. This portion may also be referred to as a heating zone. In other words, this portion of the laminate wrapper may be disposed in close proximity to a heating element, which will be described in more detail below, so that this portion of the laminate wrapper may be optimally heated. Omitting or reducing the thermal insulation layer in this portion of the laminate wrapper has the advantage that heat can optimally reach the thermally conductive layer and the aerosol-forming substrate wrapped by the thermally conductive layer. Providing a thermal insulation layer in this portion of the laminate wrapper would prevent heat from optimally reaching the aerosol-forming substrate and the thermally conductive layer. However, providing a thermal insulation layer in a different portion of the laminate wrapper achieves that the heat transferred from the heating element to the thermally conductive layer and then to the aerosol-forming substrate remains within the aerosol-forming substrate of the aerosol-generating article. The portion of the laminate wrapper that includes the thermal insulation layer is preferably a portion of the laminate wrapper that is disposed at a greater distance from the heating element than the portion of the laminate wrapper that includes only the thermally conductive layer.

[0016] The laminate wrapper may be wrapped around the entire circumference of the aerosol-forming substrate of the aerosol-generating article. Alternatively, the laminate wrapper may not be wrapped completely around the aerosol-forming substrate, if desired. Thus, the laminate wrapper may only partially cover the circumference of the aerosol-forming substrate. An additional wrapper may be disposed to wrap around the aerosol-generating article. In particular, if the laminate wrapper only partially covers the circumference of the aerosol-forming substrate, an additional wrapper may be provided to completely cover the aerosol-generating article.

[0017] The term "laminated" with respect to a wrapper means a wrapper in which at least two layers are permanently assembled together, preferably by heat, pressure, welding, or adhesives. The two layers are preferably a thermally insulating layer and a thermally conductive layer. It is possible that the laminated wrapper may include additional layers, if desired. However, the thermally conductive layer is preferably disposed directly adjacent to the aerosol-forming substrate of the aerosol-generating article. The thermally insulating layer is preferably disposed directly adjacent to the thermally conductive layer. The laminated wrapper preferably consists of a thermally conductive layer and a thermally insulating layer.

[0018] The laminate wrapper may include at least one heating area in which an insulating layer is absent or reduced. The heating area may also be referred to as a heating spot. Providing only a thermally conductive layer in a portion of the laminate wrapper allows for a heating area in which heating energy may be optimally transferred to the thermally conductive layer and to the aerosol-forming substrate inside the aerosol-generating article. The transfer of heat from the outside of the aerosol-generating article to the aerosol-forming substrate may be assisted by the thermally conductive layer of the laminate wrapper in the heating area. The laminate wrapper preferably includes a thermally conductive layer and a thermally insulating layer adjacent to the heating area. The thermally conductive layer is preferably disposed inside the thermally insulating layer. In other words, the thermally conductive layer is preferably disposed radially directly adjacent to the aerosol-forming substrate of the aerosol-generating article. The thermally insulating layer is preferably disposed wrapped around the thermally conductive layer. Heat applied to the thermally conductive layer in the heating area may travel axially within the thermally conductive layer. This heat also travels radially to the inside of the aerosol-generating article in which the aerosol-forming substrate is provided. On the other hand, in the portion of the thermally conductive layer that is covered by the thermal insulation layer, the heat of the thermally conductive layer may be insulated by the thermal insulation layer, and thus the heat in the thermally conductive layer mainly moves axially and radially inwardly to the inside of the thermally conductive layer, but not radially outwardly.

[0019] A single heating zone may be provided, in which only a thermally conductive layer is provided to encase the aerosol-generating substrate. Alternatively, multiple heating zones may be provided. Preferably, in each heating zone, only a thermally conductive layer is provided to enclose the aerosol-generating substrate. Between heating zones or in parts of the laminated wrapper adjacent to the heating zones, the laminated wrapper preferably additionally comprises a thermally insulating layer encasing around the thermally conductive layer. As will be explained in more detail below with respect to the aerosol-generating device, multiple heating zones may be used for different heating regimes of the heating element of the aerosol-generating device. Thus, multiple sections of the aerosol-forming substrate may be heated simultaneously by multiple heating zones. Alternatively or additionally, sequential heating of different heating zones may be realized.

[0020] The heating region may have an annular shape. An annular shape means a shape that extends all around the circumference of the aerosol-forming substrate. An annular shape means that in the heating region, a cylindrical outer section of the aerosol-forming substrate is surrounded by the laminated wrapper, more specifically, by the thermally conductive layer of the laminated wrapper. Advantageously, the annular shape of the heating region achieves uniform peripheral heating of the aerosol-forming substrate. In other words, the annular shape of the heating region can preferably generate a ring-shaped heating region.

[0021] The thermally conductive layer may include one or more of aluminum, tin and copper. These materials have high thermal conductivity. Thus, these materials may optimally transfer heat towards the aerosol-forming substrate disposed inside the aerosol-generating article. Furthermore, the axial heat transfer within the thermally conductive layer may be optimized by providing a material with high thermal conductivity. Furthermore, the combustion of the aerosol-generating article may be prevented by these materials of the thermally conductive layer. In this regard, the aerosol-generating article according to the present invention may be used in a heating non-combustion device that heats the aerosol-forming substrate to generate an inhalable aerosol but does not burn. Preventing the combustion of the aerosol-forming substrate prevents the formation of undesirable aerosol components. A user may accidentally or intentionally ignite the aerosol-generating article. The material of the thermally conductive layer may prevent such undesirable ignition. In other words, the thermally conductive layer may be airtight. As a result, advantageously, safe handling of the aerosol-generating articles of the present invention may be improved and unintended use of the aerosol-generating articles may be prevented.

[0022] The cut filler suitable for use with the present invention may generally be similar to the cut filler used in conventional smoking articles. The cut width of the cut filler is preferably 0.3 mm to 2.0 mm, more preferably 0.5 mm to 1.2 mm, and most preferably 0.6 mm to 0.9 mm. The cut width may play a role in the distribution of heat inside the base portion of the article. The cut width may also play a role in the draw resistance of the article. Additionally, the cut width may affect the overall density of the base portion.

[0023] The strand length of the cut filler is somewhat random, since the length of the strand depends on the overall size of the object from which the strand is cut. Nevertheless, longer strands can be cut by conditioning the material prior to cutting, for example by controlling the moisture content and overall fineness of the material. The strands preferably have a length of about 10 millimeters to about 40 millimeters before the strands are formed into the substrate section. Obviously, if the strands are disposed in a longitudinal substrate section in which the longitudinal extension of the section is less than 40 millimeters, the final substrate section may contain strands that are on average shorter than the initial strand length. The strand length of the cut filler is preferably such that about 20 percent to 60 percent of the strands extend along the entire length of the substrate section. This prevents the strands from easily detaching from the substrate section.

[0024] In a preferred embodiment, the weight of the aerosol-forming substrate is between 80 milligrams and 400 milligrams, preferably between 150 milligrams and 250 milligrams, more preferably between 170 milligrams and 220 milligrams. This amount of aerosol formation typically allows sufficient material for the formation of an aerosol. In addition, in light of the aforementioned constraints on diameter and size, this allows a balanced density of the aerosol-forming substrate between energy uptake, withdrawal resistance, and fluid passage within the substrate section in which the substrate contains the plant material.

[0025] According to the present invention, the aerosol-forming substrate is immersed with the aerosol former. The immersion of the aerosol-forming substrate can be by spraying or other suitable application methods. The aerosol former can be applied to the blend during preparation of the cut filler. For example, the aerosol former can be applied to the blend in a direct conditioning casing cylinder (DCCC). Conventional machinery can be used to apply the aerosol former to the cut filler. The aerosol former can be any suitable known compound or mixture of compounds that promotes the formation of a dense and stable aerosol during use. The aerosol former can promote the aerosol to be substantially resistant to thermal decomposition at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol formers are, for example, polyhydric alcohols (such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol, and glycerin), esters of polyhydric alcohols (such as, for example, glycerol monoacetate, diacetate, or triacetate), aliphatic esters of mono-, di-, or polycarboxylic acids (such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate), and combinations thereof.

[0026] The aerosol former may include one or more of glycerin and propylene glycol. The aerosol former may consist of glycerin or propylene glycol, or a combination of glycerin and propylene glycol.

[0027] Preferably, the amount of aerosol former is between 6 and 20 percent by weight based on the dry weight of the aerosol-forming substrate, more preferably, the amount of aerosol former is between 8 and 18 percent by weight based on the dry weight of the aerosol-forming substrate, and most preferably, the amount of aerosol former is between 10 and 15 percent by weight based on the dry weight of the aerosol-forming substrate. In some embodiments, the amount of aerosol former has a target value of about 13 percent by weight based on the dry weight of the aerosol-forming substrate. The most efficient amount of aerosol former also depends on whether the aerosol-forming substrate comprises plant lamina or homogenized plant material. For example, the type of substrate, among other factors, determines the extent to which the aerosol former can facilitate the release of a substance from the aerosol-forming substrate.

[0028] The aerosol-forming substrate of the present invention generates aerosols at lower temperatures than known tobacco cast leaf (TCL) sheets. Because the aerosol former is impregnated in the cut filler and is therefore provided on the outer surface of the cut filler, a lower temperature is already sufficient to generate aerosols. Also, the nicotine and flavors contained in the cut filler blend are more easily decomposed according to the natural internal structure of the cut filler, making them available for the aerosol former to generate inhalable aerosols. In contrast, artificially produced tobacco cast leaf sheets have a rather disordered internal structure that may hinder the migration of active ingredients to the surface.

[0029] For these reasons, the aerosol-forming substrates utilized in the aerosol-generating articles of the present invention may be able to efficiently generate sufficient aerosols at relatively low temperatures compared to previously used consumables that use tobacco cast leaf sheets. Temperatures of 150°C to 200°C in the heating chamber are sufficient for the aerosol-forming substrates of the present invention to generate sufficient aerosols, while aerosol-generating devices that use tobacco cast leaf sheets may typically use temperatures of about 250°C.

[0030] A further advantage of the present invention related to operating at lower temperatures is that there is no diminished requirement to cool the aerosol: since lower temperatures are typically used, simpler cooling functions may be sufficient, which in turn allows for the use of simpler, less complex constructions of the aerosol-generating article.

[0031] Advantageously, therefore, the aerosol-generating article of the invention comprises only a substrate part in which the aerosol-forming substrate is provided, without any additional segments or sections, such an embodiment having a particularly simple structure.

[0032] The aerosol-generating article may comprise a base portion containing the aerosol-forming substrate and a filter portion. The filter portion is preferably arranged downstream of the base portion. The base portion may be arranged directly abutting the filter portion. The filter portion may comprise, for example, a hollow tubular filter portion, preferably a hollow acetate tube (HAT), a fine hollow acetate tube (FHAT) or a plug of tow wound around a central cardboard tube, all structures of which are known from the manufacture of filter elements. The filter portion preferably comprises a hollow central space.

[0033] If desired or required, for example to achieve a sufficiently high withdrawal resistance of the aerosol-generating article, an additional filter section may be included in the aerosol-generating article. Such an additional filter section may preferably be included between the base portion and the mouth end portion. Such an additional filter section preferably comprises a filtering material such as, for example, cellulose acetate. The length of the additional filter section is preferably from about 4 millimeters to about 8 millimeters, preferably from about 5 millimeters to about 7 millimeters. The combined length of the additional filter section and the hollow tubular filter portion is preferably from about 10 millimeters to about 18 millimeters, preferably 13 millimeters.

[0034] As used herein, the terms "upstream" and "downstream" are used to describe the relative position of a component or part of a component of an aerosol-generating article according to the present invention with respect to the direction of air drawn through the aerosol-generating article during use of the aerosol-generating article.

[0035] A laminate wrapper may be provided to cover the substrate portion, or the substrate portion and the filter portion. The laminate wrapper may at least partially cover the substrate portion. Alternatively, the laminate wrapper may completely cover the substrate portion. Alternatively, the laminate wrapper may partially cover the substrate portion and partially cover the filter portion. Alternatively, the laminate wrapper may cover or completely cover the substrate portion and partially cover the filter portion, or partially cover the substrate portion and completely cover the filter portion.

[0036] The laminate wrapper may cover a length of 20 millimeters to 35 millimeters of the aerosol substrate portion. If the aerosol-generating article comprises a filter portion, the laminate wrapper may cover a length of 20 millimeters to 50 millimeters of the aerosol-generating article. The laminate wrapper may cover at least 50%, more preferably at least 70%, more preferably at least 90% of the length of the aerosol-forming substrate.

[0037] When a laminate wrapper is provided to at least partially cover the filter portion, an optimized thermal insulation can be provided to the filter portion. In this regard, the aerosol generated by heating the substrate portion containing the aerosol-forming substrate of the aerosol-generating article can be drawn towards the end of the filter portion. Insulating the filter portion can optimize the maintenance of the aerosol while it flows through the filter portion. This effect can be achieved in particular by a thermal insulating layer of the laminate wrapper. Furthermore, a thermally conductive layer of the laminate wrapper can transfer heat towards the periphery of the filter portion. This heat can optimize the maintenance of the aerosol in the filter portion or even help in the generation of the aerosol in the filter portion. Furthermore, insulating the filter portion of the aerosol-generating article can advantageously prevent unintended degradation of the filter portion due to the applied heat.

[0038] The filter portion may be formed from any suitable material or combination of materials. For example, the filter portion may be formed from one or more materials selected from the group consisting of cellulose acetate, cardboard, paper (such as crimped heat-resistant paper or crimped parchment paper), cotton, viscose, glass fiber, and other polymeric materials (such as low-density polyethylene (LDPE)). In a preferred embodiment, the filter portion is formed from cellulose acetate.

[0039] The filter portion may comprise a hollow tubular element, hi a preferred embodiment, the filter portion comprises a hollow cellulose acetate tube.

[0040] The filter portion preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0041] The filter portion may have an outer diameter of about 4 millimeters to about 8 millimeters, for example about 5 millimeters to about 6 millimeters, preferably about 5.3 millimeters. The filter portion may have a length of about 10 millimeters to about 25 millimeters.

[0042] The aerosol-generating article may be substantially cylindrical. However, alternatively, other cross-sections may be used. Indeed, the cross-section of the aerosol-generating article may vary along its length, for example by varying the cross-sectional shape or cross-sectional dimensions. The aerosol-generating article may be substantially elongated. The aerosol-generating article may have a length and a circumference substantially perpendicular to the length. The aerosol-forming substrate may be substantially cylindrical. The aerosol-forming substrate may be substantially elongated. The aerosol-forming substrate may also have a length and a circumference substantially perpendicular to the length.

[0043] The aerosol-generating article may have a total length of 30 mm to 60 mm, preferably 40 mm to 50 mm, more preferably 45 mm. The aerosol-generating article may have an outer diameter of approximately 4 mm to 8 mm, preferably 5 mm to 6 mm, more preferably about 5.3 mm. In one embodiment, the aerosol-generating article may have a total length of approximately 45 mm. Furthermore, the aerosol-forming substrate may have a length of 20 mm to 55 mm. The aerosol-forming substrate used in the aerosol-generating article is preferably a non-liquid aerosol-forming substrate. The term "non-liquid aerosol-forming substrate" as used herein relates to a substrate capable of releasing volatile compounds capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may conveniently be part of the aerosol-generating article or the smoking article.

[0044] The aerosol-forming substrate is a substrate capable of releasing a volatile compound capable of forming an aerosol. The volatile compound may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may comprise nicotine. The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds that are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco-containing material. The aerosol-forming substrate may comprise a homogenized plant-based material (including homogenized tobacco) made, for example, by a paper making process or a casting process. The aerosol-forming substrate is preferably provided as a cut filler impregnated with the aerosol former.

[0045] The thermal insulation layer may comprise one or more of paper, preferably cigarette wrapping paper, cotton or fiberglass. These materials have high insulating properties. Furthermore, these materials are readily available.

[0046] The laminate wrapper can have a thickness of from 30 micrometers to 100 micrometers, preferably from 50 micrometers to 70 micrometers, preferably from 55 micrometers to 58 micrometers, and more preferably about 56.5 micrometers.

[0047] Throughout this specification, the term "about" accounts for the inherent variation of up to ±2 of the last decimal place. For example, the term "about 56.5 micrometers" can include a range of 56.3 micrometers to 56.7 micrometers. Alternatively, the term "about" can include an uncertainty of up to 5% of whichever value is greater.

[0048] The thickness of the laminate wrapper may allow for lamination of thermally insulating and thermally conductive layers, and dimensional stability of the laminate wrapper may be achieved.

[0049] The thermally conductive layer may have a thickness of from 4 micrometers to 25 micrometers, preferably from 5 micrometers to 10 micrometers, preferably from 6 micrometers to 7 micrometers, and more preferably about 6.5 micrometers.

[0050] The thickness of the thermally conductive layer may optimize heat distribution. The thickness of the thermally conductive layer may allow for axial heat transfer through the thermally conductive layer as well as radially inward heat transfer towards the aerosol-forming substrate.

[0051] The thermal insulation layer may have a thickness of from 25 micrometers to 75 micrometers, preferably from 40 micrometers to 60 micrometers, and more preferably from 50 micrometers.

[0052] The thickness of the thermal insulation layer may optimize thermal insulation. The thermal insulation layer may act as a layer to increase the structural integrity of the laminate wrapper. The thermal insulation layer may form a support for the thermally conductive layer.

[0053] A thermal insulation layer may be disposed surrounding the thermally conductive layer. Heat may be confined inside the aerosol-generating article by the thermal insulation layer surrounding the thermally conductive layer. The thermal insulation layer is preferably the outermost layer of the aerosol-generating article.

[0054] The aerosol-generating article may have an asymmetric cross-section. The term "asymmetric cross-section" refers to a profile or cross-section of the aerosol-generating article that only allows insertion of the aerosol-generating article in a specific orientation, or in a number of specific orientations, into the heating chamber of the aerosol-generating device. In this case, the heating chamber preferably has a corresponding cross-section, which is described in more detail below with respect to the aerosol-generating device. A circular cross-section is not an asymmetric cross-section. A rectangular cross-section may be considered as an asymmetric cross-section according to the present invention. A rectangular cross-section may only allow insertion of the aerosol-generating article in two or four orientations. If the cross-section of the aerosol-generating article is square, four orientations are possible, and if it is not square, two orientations are possible. The cross-section of the aerosol-generating article may also have a shape such that an aerosol-generating article inserted into a heating chamber of a corresponding shape can only be inserted in a single orientation. Insertion that is only possible in one or more specific orientations may also be referred to as a keyed configuration of the aerosol-generating article. The term asymmetric cross-section ignores the inherent structure of the aerosol-forming substrate, in particular the random orientation of the cut filler strips, when considering symmetry.

[0055] The laminate wrapper may include a plurality of thermally conductive layers overlapping each other in the axial direction of the aerosol-generating article. According to this embodiment, different heating zones of the aerosol-generating article are defined in the axial direction of the aerosol-generating article. In the different heating zones, a different number of conductive layers may overlap. In the first heating zone, a single thermally conductive layer is preferably provided. This first heating zone may be constructed similarly to the heating zone described above. In this first heating zone, it is preferred that there is no laminate wrapper including a thermal insulating layer, and only a single thermally conductive layer is provided. In the second heating zone, two thermally conductive layers may be provided adjacent to each other in the radial direction of the aerosol-generating article. In other words, in the second heating zone, two thermally conductive layers may cover the aerosol-forming substrate. Providing a plurality of thermally conductive layers has the effect that it may take longer for heat to be transferred from the outside of the aerosol-generating article to the inside of the aerosol-generating article where the aerosol-forming substrate is provided. As a result, staged heating may be provided by these different heating zones. Of course, three or more heating zones may be provided. A third heating zone may be provided, for example in which three thermally conductive layers are arranged to surround the aerosol-forming substrate. Four or more heating zones may be provided. Each of the additional heating zones preferably comprises a further thermally conductive layer. The thermally conductive layer of the first heating zone may extend over the entire heating zone. The thermally conductive layer of the second heating zone may extend over the second heating zone and all the additional heating zones, but not over the first heating zone. In this way, a relatively simple arrangement can be achieved in which multiple heating zones are provided for a staged heating effect. The staged heating effect may generate a heating delay in different heating zones of the aerosol-generating article. Thus, a staged vaporization of the aerosol-forming substrate may be achieved in the heating zones. One heating zone may be provided for a single puff, so that an optimized substrate vaporization may be achieved for each puff. The aerosol-generating article may be configured for a specific number of puffs, and the number of heating zones may correspond to this specific number of puffs.

[0056] In addition to or as an alternative to providing multiple thermally conductive layers, multiple thermal insulation layers may be provided. The multiple heating zones mentioned above may include multiple thermal insulation layers. The laminate wrapper may include a fixed total number of layers. In each of the multiple heating zones, the total number of layers may correspond to the total number of layers of the laminate wrapper. For example, if the laminate wrapper includes four layers, an insulation zone may be provided in which only four insulation layers are disposed. A first heating zone may be provided with a single thermally conductive layer and three thermal insulation layers. A second heating zone may be provided with two thermally conductive layers and two thermal insulation layers. A third heating zone may be provided with three thermally conductive layers and one thermal insulation layer. Finally, a fourth heating zone may be provided with four thermally conductive layers and no insulation layers. Of course, this example is merely illustrative. Fewer or more heating zones may be provided as desired. When thermal insulation layers are provided in the heating zones as described herein, the heating zone having the greatest number of thermally conductive layers and the least number of thermally insulating layers is likely to transfer the greatest amount of thermal energy from the outside of the aerosol-generating article to the inside of the aerosol-generating article on which the aerosol-forming substrate is disposed. Each successive heating zone having a decreasing number of thermally conductive layers and an increasing number of thermally insulating layers is likely to transfer a smaller amount of thermal energy from the outside of the aerosol-generating article to the inside of the aerosol-generating article. Illustratively, when the heating element of the aerosol-generating device uniformly heats the outside of the aerosol-generating article, the heat gradually reaches the inside of the aerosol-generating article to generate an inhalable aerosol. This effect may be desirable to generate a gradual heating effect. Furthermore, by providing a laminate wrapper with a fixed number of layers, the thickness of the laminate wrapper and therefore the diameter of the aerosol-generating article can be kept constant.

[0057] The thermally conductive layer may include one or more of a hole, a ring shape, a spiral shape, a spiral shape with a width variation, an axial variation, and a radial thickness variation.

[0058] Different shapes of the thermally conductive layer may realize different heating regimes. These different shapes of the thermally conductive layer may be advantageously used to optimize the vaporization of the aerosol-forming substrate. When several thermally conductive layers are provided, each of the thermally conductive layers may have a desired shape, which may be similar or different to the shape of the further thermally conductive layers. The thermal insulation layer of the laminate wrapper, arranged to partially cover the thermally conductive layer, may be arranged such that the shape of the thermally conductive layer not covered by the thermal insulation layer may have a different shape. For example, a ring shape of the thermally conductive layer may be realized in a uniform thermally conductive layer that is partially covered by the thermal insulation layer, such that the ring-shaped portion of the thermally conductive layer is not covered by the thermal insulation layer. The same may apply to the further above-mentioned shapes of the thermally conductive layer. Alternatively, the thermally conductive layer itself may have such a shape. When the thermally conductive layer has an axial variation, it is preferred that the above-mentioned heating zones are different shapes from each other. For example, a first heating zone may have an annular shape with a relatively small axial length, and then a second heating zone may have a longer axial length. For example, the actual length of the first heating zone may be about 1 millimeter, and the axial length of the second heating zone may be about 2 millimeters. This is understood to be merely exemplary. Any desired axial length and shape of the one or more heating zones may be selected. The variation in radial thickness of the thermally conductive layer means that the thermally conductive layer does not have a uniform thickness. In some embodiments, the thickness of the thermally conductive layer may vary over the axial length of the thermally conductive layer. In particular, the different heating zones mentioned above may be a single thermally conductive layer with varying thickness instead of multiple thermally conductive layers. Similarly, the thickness of the thermal insulation layer may vary, if desired.

[0059] The present invention also relates to an aerosol generating device comprising a heating chamber and a heating element disposed adjacent the heating chamber, the heating chamber configured for insertion of the aerosol-generating article as described above, the heating element configured to heat a heating region of the aerosol-generating article having only a thermally conductive layer disposed therein when the aerosol-generating article is inserted into the heating chamber.

[0060] The heating chamber may have a cylindrical shape for insertion of the aerosol-generating article. The heating chamber may be a recess. The heating chamber may have a circular profile or cross-section. As mentioned above, when the aerosol-generating article has an asymmetric profile, the heating chamber preferably has a corresponding asymmetric profile. For example, when the aerosol-generating article has a rectangular profile, the heating chamber preferably has a rectangular profile. When the aerosol-generating article has an asymmetric profile configured to only allow insertion of the aerosol-generating article into the heating chamber in a single orientation, the heating chamber preferably has a corresponding cross-section. For example, the aerosol-generating article may include grooves, nuts, shoulders, or similar elements along the length of the aerosol-generating article and on the exterior of the aerosol-generating article, and the heating chamber may include corresponding grooves, nuts, shoulders, or similar elements to engage with elements of the aerosol-generating article to allow insertion of the aerosol-generating article in a single specific orientation.

[0061] A heating element may be disposed within or around the heating chamber for heating an aerosol-generating article insertable into the heating chamber. Alternatively or additionally, an internal heating element may be provided, e.g., a pin or blade that is at least partially inserted into the aerosol-forming substrate for use.

[0062] For example, the device may include an external heating element positioned around the periphery of the heating chamber. The external heating element may take any suitable form. For example, the external heating element may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foils may be shaped to fit the periphery of the heating chamber. Alternatively, the external heating element may take the form of a metal grid(s), a flexible printed circuit board, a molded integrated circuit device (MID), a ceramic heating element, a flexible carbon fiber heating element, or may be formed using a coating technique such as plasma deposition on a substrate of suitable shape. The external heating element may also be formed using a metal that has a well-defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of a suitable insulating material. An external heating element formed in this manner may be used to both heat the external heating element and monitor its temperature during operation. The heating element may be configured to heat to a temperature of approximately 200 degrees Celsius. The heating element may also be configured as an induction heating element, in which case the heating element preferably includes an induction coil. In this embodiment, the aerosol-forming substrate of the aerosol-generating article may include a susceptor material for generating heat inside the aerosol-forming substrate. Alternatively, in this embodiment, a susceptor material, for example in the form of a blade or pin, may be disposed inside the heating chamber for penetrating the aerosol-forming substrate of the aerosol-generating article when the aerosol-generating article is inserted into the heating chamber.

[0063] The heating elements may be arranged around the heating chamber to heat the heating chamber uniformly. This may have the effect that the aerosol-generating article, in particular the substrate part of the aerosol-generating article, is heated uniformly when the aerosol-generating article is inserted into the heating chamber. As mentioned above, the laminated wrapper surrounding the aerosol-generating article may have a specific structure that allows for staged heating of the aerosol-forming substrate inside the aerosol-generating article. In particular, the laminated wrapper may generate different heating zones. These different heating zones may be particularly utilized when the aerosol-generating article is heated uniformly from the outside by heating elements arranged to surround the heating chamber.

[0064] Alternatively, the heating element may be configured to heat a specific region of the aerosol-generating article when the article is inserted into the heating chamber. The heating element may include a plurality of separately controllable heating portions for this purpose. These separately controllable heating portions may be arranged along the longitudinal length of the heating chamber to heat separate sections of the aerosol-generating article. The separately controllable heating portions are preferably configured to heat different heating regions of the aerosol-generating article. The separately controllable heating portions may each completely surround the heating chamber. The separately controllable heating portions may be controllable by an electric circuit, which is described in more detail below. Alternatively or additionally, the separately controllable heating portions may be arranged parallel to the longitudinal axis of the heating chamber. Instead of separately controllable heating portions, the heating element may be configured to generate a heating gradient during heating. The heating element may be configured to generate a heating gradient along the longitudinal axis of the heating chamber parallel to the longitudinal axis of the heating chamber.

[0065] The heating element may be configured to radiate heat towards the aerosol-generating article when the aerosol-generating article is inserted into the heating chamber. The heat may be optimally absorbed and transferred by a thermally conductive layer of the laminate wrapper of the aerosol-generating article. The heat may be radiated or transferred to the aerosol-forming substrate of the aerosol-generating article by the thermally conductive layer. This effect is particularly useful when the heat source does not apply heat homogeneously. Thus, the thermally conductive layer can transport heat from the heat source along the aerosol-generating substrate and distribute the heat homogeneously, if desired, when the coating of the thermally conductive layer is homogeneous across the aerosol-generating substrate. Alternatively, the heat from the heat source may be selectively distributed across the aerosol-generating substrate when the coating of the thermally conductive layer is not across the entire aerosol-generating substrate.

[0066] As used herein, "aerosol-generating device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate may be part of an aerosol-generating article. The aerosol-generating device may be a device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol. The aerosol-generating device may comprise a housing, an electrical circuit, a power source, a heating chamber, and a heating element. The aerosol-generating device may optionally comprise a mouthpiece.

[0067] The electrical circuit may comprise a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of the controller. The electrical circuit may comprise further electronic components. The electrical circuit may be configured to regulate the power supply to the heating element. Power may be supplied to the heating element continuously after activation of the system, or may be supplied intermittently, such as after every puff. Power may be supplied to the heating element in the form of current pulses. The electrical circuit is preferably configured to monitor the electrical resistance of the heating element and to control the power supply to the heating element depending on the electrical resistance of the heating element.

[0068] The device may include a power source (typically a battery) within the main body. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for the storage of sufficient energy for one or more use experiences. For example, the power source may have a capacity sufficient to continuously generate aerosol for about 6 minutes, or a multiple of 6 minutes. In another embodiment, the power source may have a capacity sufficient to generate aerosol for multiple puffs.

[0069] The power source may be any suitable power source, for example a direct current voltage source such as a battery. In one embodiment, the power source is a lithium ion battery. Alternatively, the power source may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium-based battery (e.g., a lithium cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery).

[0070] The aerosol generating device may comprise a mouthpiece. The mouthpiece may be a separate element or may be integrally formed with the aerosol generating device. The mouthpiece may be connectable or connected to the aerosol generating device, preferably by a hinge. The mouthpiece may be configured as a Venturi element. The mouthpiece may be configured to be connectable with the aerosol generating article. The mouthpiece may be configured to be insertable into a filter portion of the aerosol generating article.

[0071] The present invention relates to a system comprising an aerosol generating device as described herein and an aerosol generating article as described herein. The present invention also relates to a system comprising an aerosol generating article as described herein and a mouthpiece, preferably a Venturi element as described herein. The present invention also relates to a system comprising an aerosol generating device, an aerosol generating article, and a mouthpiece.

[0072] The present invention also relates to a method for producing an aerosol-generating article, the method comprising: i. providing an aerosol-generating article comprising an aerosol-forming substrate, the aerosol-forming substrate comprising cut plant material filler, the cut plant material filler comprising at least 25 percent plant lamina by total weight of the plant material, the aerosol-forming substrate further comprising between about 6 percent and about 20 percent aerosol formers; ii. wrapping a laminated wrapper at least partially around the aerosol-forming substrate, the laminated wrapper including a thermally conductive layer and a thermally insulating layer, the thermally conductive layer and the thermally insulating layer overlapping along an axial direction of the aerosol-generating article.

[0073] The method may include the step of inserting the aerosol-generating article into a heating chamber of an aerosol generating device.The method may include the step of heating the aerosol-generating article.

[0074] Features described with respect to one aspect may be equally applied to other aspects of the invention.

[0075] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0076] [Figure 1] FIG. 1 shows a cross-sectional view of an aerosol-generating article inserted into the heating chamber of an aerosol-generating device. [Diagram 2] FIG. 2 illustrates different embodiments of the thermally conductive layer of a laminate wrapper for an aerosol-generating article. [Diagram 3] FIG. 3 shows a cross-sectional view of an embodiment of a laminate wrapper having multiple thermally conductive layers and multiple thermally insulating layers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0077] Figure 1 shows an aerosol-generating article 10. The aerosol-generating article 10 is inserted into a heated chamber 12 of an aerosol-generating device 14. The aerosol-generating article 10 includes a substrate portion 16 that contains an aerosol-forming substrate. In the embodiment shown in Figure 1, the aerosol-generating article 10 further includes a filter portion 18 in the form of a hollow acetate tube. The filter portion 18 is disposed downstream of the substrate portion 16. The filter portion 18 is optional.

[0078] 1 shows a laminate wrapper 20 wrapped around the substrate portion 16 and the filter portion 18 of the aerosol-generating article 10. If the filter portion 18 is not provided, the laminate wrapper 20 is wrapped only around the substrate portion 16. The laminate wrapper 20 includes a thermally conductive layer 22 and a thermally insulating layer 24. The thermally conductive layer 22 is disposed on the inside, meaning directly adjacent to the aerosol-forming substrate or filter portion 18. The thermally insulating layer 24 is disposed wrapped around the thermally conductive layer 22.

[0079] The thermally insulating layer 24 and the thermally conductive layer 22 overlap along the longitudinal length of the aerosol-generating article 10. In the embodiment shown in FIG. 1, the bottom of the aerosol-generating article 10, the upstream end 26 of the aerosol-generating article 10, is wrapped only with the thermally conductive layer 22. Thus, the substrate portion 16 is wrapped with the thermally conductive layer 22. The top of the aerosol-generating article 10, the downstream end 28 of the aerosol-generating article 10, is provided with a filter portion 18. The filter portion 18 is wrapped only with the thermally insulating layer 24 of the laminated wrapper 20. Between the portion of the substrate portion 16 adjacent the upstream end 26 of the aerosol-generating article 10 and the filter portion 18 adjacent the downstream end 28 of the aerosol-generating article 10, the laminated wrapper 20 packaging the aerosol-generating article 10 includes the thermally conductive layer 22 and the thermally insulating layer 24.

[0080] As shown in FIG. 1, when the aerosol-generating article 10 is inserted into the aerosol-generating device 14, the heating element 30 of the aerosol-generating device 14 may be disposed adjacent to the thermally conductive layer 22 near the upstream end 26 of the aerosol-generating article 10. This region of the aerosol-generating article 10 covered only by the thermally conductive layer 22 is configured as a heating region 32. In this region, the heat radiated by the heating element 30 transfers directly into the thermally conductive layer 22 of the laminate wrapper 20. Thus, the heat is absorbed by the thermally conductive layer 22 and further transferred towards the aerosol-forming substrate contained within the aerosol-generating article 10. Furthermore, the heat absorbed by the thermally conductive layer 22 is transferred into the thermally conductive layer 22 in the axial direction of the aerosol-generating article 10 such that uniform heating may be achieved. In other words, a relatively small heating element 30 may be provided to heat a relatively small heating region 32 of the aerosol-generating article 10 compared to the full size of the substrate portion 16 of the aerosol-generating article 10. Nonetheless, the high thermal conductivity of the thermally conductive layer 22 allows heat to be distributed evenly across the substrate portion 16 of the aerosol-generating article 10 .

[0081] Alternatively, the heating element 30 may be disposed to surround the entire heating chamber 12 or a majority of the heating chamber 12 to achieve more uniform heating of the aerosol-generating article 10 .

[0082] The thermal insulation layer 24 absorbs heat inside the aerosol-generating article 10 when heat reaches the inside of the aerosol-generating article 10 via the thermally conductive layer 22. As seen in FIG. 1, the thermal insulation layer 24 preferably extends across the filter portion 18 disposed adjacent the downstream end 28 of the aerosol-generating article 10. In this manner, heat does not escape, or escapes at a reduced rate, in the region of the filter portion 18. This functionality improves aerosol formation and stabilizes the aerosol as it is drawn from the substrate portion 16 through the filter portion 18 during a puff.

[0083] 1 illustrates further components of the aerosol generating device 14 for operating the aerosol generating device 14. In this regard, the aerosol generating device 14 includes a power source 34, preferably a battery, for powering the heating element 30. The delivery of electrical energy from the power source 34 to the heating element 30 is controlled by an electrical circuit 36.

[0084] As will be explained below with respect to Figures 2 and 3, a graded heating effect may be achieved by the laminate wrapper 20 of the aerosol-generating article 10. Figure 2 shows different embodiments of the laminate wrapper 20, more specifically the thermally conductive layer 22 of the laminate wrapper 20. The upper part of Figure 2 shows an embodiment in which holes 38 are provided in the thermally conductive layer 22. The holes 38 may change the heat transfer properties of the thermally conductive layer 22. As shown in the left part of the aerosol-generating article 10 shown in the upper part of Figure 2, more holes 38 may be provided in the upstream region of the substrate portion 16 compared to the downstream region of the substrate portion 16. As a result, a heating region 32 may be realized in which the aerosol-forming substrate is heated faster or slower. Thus, a graded heating effect may be achieved.

[0085] 2 shows an embodiment in which the thermally conductive layer 22 is provided having an annular shape. A plurality of heating zones 32 are provided by a plurality of annular rings surrounding the periphery of the aerosol-forming substrate. The portions between the heating zones 32 may be covered by one or more thermally insulating layers 24.

[0086] 2 shows an embodiment in which the thermally conductive layer 22 has a spiral configuration. This embodiment may be achieved by providing a strip of the thermally conductive layer 22 and wrapping the strip around the aerosol-forming substrate. Alternatively, a continuous thermally conductive layer 22 may be provided, and portions between the spiral portions of the thermally conductive layer 22 may be covered by one or more thermally insulating layers 24. The spiral portions of the thermally conductive layer 22 may provide the heating zones 32 of the aerosol-generating article 10.

[0087] FIG. 3 shows a further embodiment of the laminate wrapper 20 in which multiple thermally insulating layers 24 and multiple thermally conductive layers 22 are provided. The embodiment shown in FIG. 3 is particularly useful when the heating element 30 of the aerosol-generating device 14 uniformly heats the periphery of the aerosol-generating article 10 when the article is inserted into the heating chamber 12. The multiple layers of the laminate wrapper 20 shown in FIG. 3 are provided to create multiple heating zones. The left portion of the laminate wrapper 20 shown in FIG. 3 shows a first heating zone 40 in which three thermally conductive layers 22 are provided. In this zone, heat can be transferred at high speed through the thermally conductive layers 22 into the thermoforming substrate contained within the heat-generating article. The central portion of the laminate wrapper 20 shows a second heating zone 42 in which two thermally conductive layers 22 are disposed to surround the aerosol-forming substrate and a single thermally insulating layer 24 is disposed to surround the two thermally conductive layers 22. This second heating area 42 takes longer to heat up due to the thermal insulation layer 24. Thus, if all heating areas are uniformly heated by the heating element 30 of the aerosol generating device 14, a graded heating effect can be achieved, as shown by the arrows in Fig. 3 indicating the direction of heat. The first heating area 40 can heat up faster than the second heating area 42. The right part of Fig. 3 shows a third heating area 44, where a single thermally conductive layer 22 and two thermal insulation layers 24 are provided. This heating area heats up even slower than the second heating area 42.

[0088] 1. An aerosol-generating article comprising: an aerosol-forming substrate, the aerosol-forming substrate comprising a cut plant material filler, the cut plant material filler comprising at least 25 percent plant lamina per total weight of the plant material, and the aerosol-forming substrate further comprising about 6 percent to about 20 percent aerosol formers; a laminate wrapper disposed at least partially wrapped around the aerosol-forming substrate, the laminate wrapper including a thermally conductive layer and a thermally insulating layer; An aerosol-generating article, wherein the thermally conductive layer and the thermally insulating layer overlap along an axial direction of the aerosol-generating article. 2. The aerosol-generating article described in 1, wherein the laminate wrapper includes at least one heating area in which only the thermally conductive layer is disposed. 3. The aerosol-generating article described in 2, wherein the heating region has an annular shape. 4. An aerosol-generating article described in any one of 1 to 3, wherein the thermally conductive layer contains one or more of aluminum, tin, and copper. 5. An aerosol-generating article according to any one of 1 to 4, wherein the thermal insulation layer comprises one or more of paper, preferably cigarette wrapping paper. 6. An aerosol-generating article according to any one of 1 to 5, wherein the laminate wrapper has a thickness of from 30 micrometers to 100 micrometers, preferably from 50 micrometers to 70 micrometers, preferably from 55 micrometers to 58 micrometers, more preferably about 56.5 micrometers. 7. An aerosol-generating article according to any one of 1 to 6, wherein the thermally conductive layer has a thickness of from 4 micrometers to 25 micrometers, preferably from 5 micrometers to 10 micrometers, preferably from 6 micrometers to 7 micrometers, more preferably about 6.5 micrometers. 8. An aerosol-generating article according to any one of 1 to 7, wherein the thermal insulation layer has a thickness of 25 micrometers to 75 micrometers, preferably 40 micrometers to 60 micrometers, and more preferably 50 micrometers. 9. An aerosol-generating article described in any one of 1 to 8, wherein the thermal insulation layer is arranged so as to surround the thermal conductive layer. 10. An aerosol-generating article according to any one of 1 to 9, wherein the aerosol-generating article has an asymmetric profile. 11. An aerosol-generating article described in any one of 1 to 10, wherein the laminated wrapper comprises multiple thermally conductive layers overlapping each other in the axial direction of the aerosol-generating article. 12. An aerosol-generating article described in any one of 1 to 11, wherein the thermally conductive layer comprises one or more of a hole, a ring shape, a spiral shape, a spiral shape with a varying width, an axial variation, and a varying radial thickness. 13. An aerosol-generating article described in any one of 1 to 12, wherein the aerosol-generating article further comprises a tubular filter section downstream of the aerosol-forming substrate, and the thermally conductive layer is arranged at least partially wrapped around the tubular filter section. 14. An aerosol generating device comprising: A heating chamber; a heating element disposed adjacent to the heating chamber; An aerosol generating device, wherein the heating chamber is configured for insertion of an aerosol-generating article described in any one of 1 to 13, and when the aerosol-generating article is inserted into the heating chamber, the heating element is configured to heat a heating region of the aerosol-generating article in which only the thermally conductive layer is disposed. 15. A method for producing an aerosol-generating article, said method comprising: i. providing an aerosol-generating article comprising an aerosol-forming substrate; ii. wrapping a laminated wrapper at least partially around the aerosol-forming substrate, the laminated wrapper comprising a thermally conductive layer and a thermally insulating layer, the thermally conductive layer and the thermally insulating layer overlapping along an axial direction of the aerosol-generating article.

Claims

1. 1. An aerosol-generating article comprising: an aerosol-forming substrate, the aerosol-forming substrate comprising a cut plant material filler, the cut plant material filler comprising at least 25 percent plant lamina per total weight of the plant material, the aerosol-forming substrate further comprising about 6 percent to about 20 percent of an aerosol former; a laminate wrapper disposed at least partially wrapped around the aerosol-forming substrate, the laminate wrapper including a thermally conductive layer and a thermally insulating layer; the laminate wrapper having a thickness of 30 micrometers to 100 micrometers; the thermally conductive layer and the thermally insulating layer overlap along an axial direction of the aerosol-generating article; The aerosol-generating article comprises a base portion containing the aerosol-forming substrate, and a filter portion, An aerosol-generating article, wherein the laminate wrapper covers only the substrate portion.

2. 2. The aerosol-generating article of claim 1, wherein the laminate wrapper includes at least one heating area in which only the thermally conductive layer is disposed.

3. The aerosol-generating article of claim 2 , wherein the heating region has an annular shape.

4. 4. The aerosol-generating article according to claim 1, wherein the thermally conductive layer comprises one or more of aluminum, tin, and copper.

5. 5. The aerosol-generating article of claim 1, wherein the thermal insulation layer comprises one or more papers.

6. 6. The aerosol-generating article of claim 1, wherein the laminate wrapper has a thickness of from 50 micrometers to 70 micrometers.

7. 7. The aerosol-generating article according to claim 1, wherein the thermally conductive layer has a thickness of from 4 micrometers to 25 micrometers.

8. 8. The aerosol-generating article of claim 1, wherein the thermal insulation layer has a thickness of from 25 micrometers to 75 micrometers.

9. 9. The aerosol-generating article according to claim 1, wherein the thermal insulation layer is disposed so as to surround the thermally conductive layer.

10. 10. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating article has an asymmetric profile.

11. An aerosol-generating article according to any one of claims 1 to 10, wherein the laminate wrapper comprises a plurality of thermally conductive layers overlapping one another in the axial direction of the aerosol-generating article.

12. 12. The aerosol-generating article of any one of claims 1 to 11, wherein the thermally conductive layer comprises one or more of a hole, a ring shape, a spiral shape, a spiral shape with a varying width, an axial variation, and a varying radial thickness.

13. 13. The aerosol-generating article according to any one of claims 1 to 12, wherein the aerosol-generating article further comprises a tubular filter section downstream of the aerosol-forming substrate, and the thermally conductive layer is arranged at least partially wrapped around the tubular filter section.

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