CN117545377A

CN117545377A - Thermally enhanced aerosol-forming substrate

Info

Publication number: CN117545377A
Application number: CN202280044233.4A
Authority: CN
Inventors: 黄后学; A·阿基斯库马尔
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2021-07-07
Filing date: 2022-07-07
Publication date: 2024-02-09
Also published as: CN117580472A; CN117651501A

Abstract

An aerosol-forming substrate for use in a heated aerosol-generating article is provided, the aerosol-forming substrate comprising a co-laminated sheet comprising a layer of aerosol-forming material and a layer of carbon-based thermally conductive material.

Description

Thermally enhanced aerosol-forming substrate

Technical Field

The present disclosure relates to an aerosol-forming substrate. The present disclosure also relates to a strip comprising an aerosol-forming substrate, an aerosol-generating article and an aerosol-generating system, and methods of manufacturing an aerosol-forming substrate, a strip and an aerosol-generating article.

Background

A typical aerosol-generating system comprises an aerosol-generating device and an aerosol-generating article comprising an aerosol-forming substrate. In use, the aerosol-generating device interacts with the aerosol-generating article to heat the aerosol-forming substrate and cause the aerosol-forming substrate to release the volatile compound. These compounds then cool to form an aerosol, which is inhaled by the user.

Known aerosol-forming substrates generally have a relatively low thermal conductivity. This may be undesirable, in particular in aerosol-generating systems in which the blade is inserted into the aerosol-forming substrate and heated in order to heat the aerosol-forming substrate. This is because the low thermal conductivity of the aerosol-forming substrate may lead to a relatively large temperature gradient of the aerosol-forming substrate during use. This may mean that the portion of the aerosol-forming substrate located furthest from the blade does not reach high temperatures and therefore does not release as much volatile compounds as would be released if the aerosol-forming substrate had a higher thermal conductivity. In other words, the low thermal conductivity of the aerosol-forming substrate may undesirably result in low efficiency of use of the aerosol-forming substrate.

Furthermore, known aerosol-forming substrates are generally not heatable to operating temperatures by induction. This means that for induction heating a separate susceptor element is usually required. This may increase costs. In addition, this may lead to the same problems as discussed above. For example, in case the inductively heated susceptor element is placed in a central position in the substrate, the portion of the aerosol-forming substrate located furthest from the susceptor element may not reach a high temperature and may therefore not release a lot of volatile compounds.

Attempts have been made to increase the thermal conductivity of aerosol-forming substrates. However, to date, these attempts have been inadequate in one or more respects.

Disclosure of Invention

It is an object of the present invention to provide an improved aerosol-forming substrate, for example an aerosol-forming substrate having an increased thermal conductivity. It is also an object of the present invention to provide such an aerosol-forming substrate having increased thermal conductivity while also having improved tensile strength.

According to the present disclosure, an aerosol-forming substrate is provided. The aerosol-forming substrate may be suitable for use in a heated aerosol-generating article. The aerosol-forming substrate may comprise a co-laminated sheet. The co-laminate sheet may include a layer of aerosol-forming material. The co-laminate sheet may include a layer of carbon-based thermally conductive material.

Thus, according to a first aspect of the present disclosure there is provided an aerosol-forming substrate for use in a heated aerosol-generating article, the aerosol-forming substrate comprising a co-laminated sheet comprising a layer of aerosol-forming material and a layer of carbon-based thermally conductive material.

As used herein, the term "carbon-based thermally conductive material" is used to refer to a material comprising carbon, such as a material comprising or consisting of one or more of graphite, expanded graphite, graphene, carbon nanotubes, and charcoal.

A carbon-based thermally conductive material layer comprising or consisting of at least one of graphite and expanded graphite may be particularly preferred. The carbon-based thermally conductive material layer may be referred to as a carbon material or a carbonaceous material.

Advantageously, the carbon-based thermally conductive material layer may increase the thermal conductivity of the aerosol-forming substrate. This may provide a more uniform temperature distribution throughout the matrix during use. This may allow a greater proportion of the aerosol-forming substrate to reach a sufficiently high temperature to release volatile compounds and thus allow for more efficient use of the aerosol-forming substrate. Alternatively or additionally, the increased thermal conductivity of the substrate may allow the heater (e.g., a heating blade configured to heat the substrate) to operate at a lower temperature and thus require less power.

Advantageously, the layer of carbon-based thermally conductive material (such as those listed above, particularly materials including graphite and expanded graphite) may have a high thermal conductivity and a low density, and thus, be able to greatly increase the thermal conductivity of the aerosol-forming substrate without significantly increasing the density of the aerosol-forming substrate. It may be advantageous to avoid significantly increasing the density of the aerosol-forming substrate. This is because for a given volume of substrate, an increase in density can increase the weight and therefore the cost of transportation.

As used herein, the term "sheet" refers to a layered element having a width and a length that is substantially greater than its thickness. The width of the sheet may be greater than 10mm, preferably greater than 20, 30, 40, 50, 60, 70, 80, 90, 100 millimeters. The width of the sheet may be less than 300, 250, 200, 150 millimeters. As will be described, the co-laminated sheet may be subjected to a processing step such as aggregation. In this case, the "width" of the sheet may refer to the width of the sheet prior to gathering.

As used herein, the term "co-laminated sheet" refers to a single sheet formed from two or more layers of material in intimate contact with each other. In particular, the co-laminate sheet may comprise a layer of aerosol-forming material in intimate contact with a layer of thermally conductive material. The intimate contact between the aerosol-forming material layer and the carbon-based thermally conductive material layer means that heat may be transported throughout the aerosol-forming material layer by conduction through the aerosol-forming material layer. This increases the thermal conductivity of the aerosol-forming substrate.

The carbon-based thermally conductive material layer may have a length and width similar to or the same as the length and width of the aerosol-forming material layer.

The carbon-based thermally conductive material layer may be in contact with the aerosol-forming material layer across substantially the entire surface of the thermally conductive material.

The layers of the co-laminated sheet may form a single sheet.

The co-laminate sheet may comprise more than one layer of aerosol-forming material. The co-laminate sheet may include more than one layer of thermally conductive material. The or each aerosol-forming material layer may be sandwiched between layers of thermally conductive material. Alternatively or in addition, the or each layer of thermally conductive material may be sandwiched between layers of aerosol-forming material.

The co-laminate sheet may include one or more additional layers including materials other than the carbon-based thermally conductive material and the aerosol-forming material.

The or each layer of thermally conductive material may be in the form of a film or foil. The film or foil is thin so that only a small amount of the aerosol-forming substrate may be occupied by one or more layers of thermally conductive material. However, since the thermally conductive layer may be provided as a layer which may advantageously extend throughout the aerosol-forming substrate, the thermal conductivity of the substrate is improved throughout the substrate.

The or each layer of thermally conductive material may be flexible. The or each aerosol-forming material layer may be flexible. In this way, the co-laminate sheet may also be flexible. This may be particularly advantageous when the co-laminated sheets are gathered to form an aerosol-forming substrate strip, as will be described below. The gathered co-laminate sheet preferably extends along substantially the entire length of the strip and extends across substantially the entire cross-sectional area of the strip.

The or each layer of thermally conductive material may have a thickness of less than 10, 5, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03 or 0.02 mm.

The or each layer of thermally conductive material may have a thickness of between 10 and 0.02 mm, or 5 and 0.02 mm, 3 and 0.02 mm, 2 and 0.02 mm, 1 and 0.02 mm, 0.9 and 0.02 mm, 0.8 and 0.02 mm, 0.7 and 0.02 mm, 0.6 and 0.02 mm, 0.5 and 0.02 mm, 0.4 and 0.02 mm, 0.3 and 0.02 mm, 0.2 and 0.02 mm, 0.1 and 0.02 mm, 0.09 and 0.02 mm, 0.08 and 0.02 mm, 0.07 and 0.02 mm, 0.06 and 0.02 mm, 0.05 and 0.02 mm, and 0.04 and 0.02 mm.

Preferably, the carbon-based thermally conductive material layer may comprise or consist of carbon fibers, graphite or graphene.

Even more preferably, the layer of carbon-based thermally conductive material may comprise or consist of expanded graphite.

Alternatively, the carbon-based thermally conductive material layer may include both graphite and expanded graphite.

The carbon-based thermally conductive material layer may be composed of flexible graphite or a foil or film of flexible graphite and expanded graphite.

The carbon-based thermally conductive material layer may have a density less than or equal to the density of the aerosol-forming material.

The layer of thermally conductive material may have a density that is at least 1%, 2%, 5%, 10%, 15%, 20%, 25% or 30% less than the density of the aerosol-forming material.

The aerosol-forming substrate may have a density of less than 1050, 1000, 950, 900, 850, 800, 750, 700 or 650kg/m 3.

The aerosol-forming substrate may have a particle size of between 500 and 900kg/m ³ Between, for example, 600 and 800kg/m ³ Density of the two.

The carbon-based thermally conductive material layer may have a weight of less than 3, 2, 1.8, 1.5, 1.2, 1, 0.8, 0.5, 0.2, 0.1, 0.05, 0.02 grams/cubic centimeter (g/cm) ³ ) Is a density of (3).

The carbon-based thermally conductive material layer may have a weight of greater than 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 0.8, 1, 1.2, 1.5, or 1.8 grams/cubic centimeter (g/cm) ³ ) Is a density of (3).

The carbon-based thermally conductive material layer may have a thickness of 0.01 and 3, 0.01 and 2, 0.01 and 1.8, 0.01 and 1.5, 0.01 and 1.2, 0.01 and 1, 0.01 and 0.8, 0.01 and 0.5, 0.02 and 3, 0.02 and 2, 0.02 and 1.8, 0.02 and 1.5, 0.02 and 1.2, 0.02 and 1, 0.02 and 0.8, 0.02 and 0.5, 0.01 and 3, 0.05 and 2, 0.05 and 1.8, 0.05 and 1.5, 0.05 and 1.2, 0.05 and 1, 0.05 and 0.8, 0.05 and 0.5g/cm3, 0.1 and 2 densities between 0.1 and 1.8, 0.1 and 1.5, 0.1 and 1.2, 0.1 and 1, 0.1 and 0.8, 0.1 and 0.5, 0.2 and 3, 0.2 and 2, 0.2 and 1.8, 0.2 and 1.5, 0.2 and 1.2, 0.2 and 1, 0.2 and 0.8, 0.2 and 0.5, 0.5 and 3, 0.5 and 2, 0.5 and 1.8, 0.5 and 1.5, 0.5 and 1.2, 0.5 and 1, 0.8 and 3, 0.8 and 2, 0.8 and 1.8, 0.8 and 1.5, 0.8 and 1.2, 0.8 and 1 g/cc (g/cm 3).

Advantageously, the use of a lower density layer of thermally conductive material may result in a lower density matrix. This may reduce the weight of a given volume of substrate and thus reduce the cost of transportation.

The carbon-based thermally conductive material layer may have a tensile strength greater than 1, 2, 3, 4, 5, 6, 7, 8, or 9 megapascals (MPa).

Providing an aerosol-forming substrate in the form of a co-laminated sheet comprising such a layer of carbon-based thermally conductive material may advantageously increase the overall tensile strength of the substrate. Further, the carbon-based thermally conductive material layer may provide support for the aerosol-forming material layer. Thus, it may not be necessary for the strip of aerosol-generating substrate to comprise an additional support layer. In some embodiments, the aerosol-forming material may advantageously be cast directly onto the carbon-based thermally conductive material layer during the manufacture of the aerosol-forming substrate.

The layer of carbon-based thermally conductive material may be comprised of a foil or film comprising at least 90 wt%, 95 wt%, 97 wt%, 99 wt%, 99.5 wt%, 99.9 wt% graphite or expanded graphite.

The carbon-based thermally conductive material layer may comprise or consist of a reconstituted carbon-based material, preferably a reconstituted sheet of graphite or expanded graphite, even more preferably a reconstituted graphite or expanded graphite film or foil.

The reconstituted carbon-based material may comprise thermally conductive particles. Each of the thermally conductive particles may have a thermal conductivity of at least 1 watt/meter kelvin [ W/(mK) ] in at least one direction at 25 degrees celsius. Some or all of the thermally conductive particles include carbon, for example at least 10, 30, 50, 70, 90, 95, 98, or 99 wt% carbon. Optionally, some or all of the thermally conductive particles include one or more of graphite, expanded graphite, graphene, carbon nanotubes, and charcoal. Optionally, some or all of the thermally conductive particles are graphite particles. Optionally, some or all of the thermally conductive particles are expanded graphite particles. Optionally, some or all of the thermally conductive particles are graphene particles. Advantageously, such materials may have a relatively high thermal conductivity.

The reconstituted carbon-based material may comprise at least 10%, 20%, 30%, 40%, 50%, 60%, 70% by weight of thermally conductive particles. The reconstituted carbon radical may comprise less than 90%, 95%, 80% by weight of thermally conductive particles.

The reconstituted carbon-based material may include an aerosol former. The reconstituted carbon-based material may comprise between 7 and 60% by weight of aerosol former on a dry weight basis.

The reconstituted carbon-based material may comprise fibres. The reconstituted carbon-based material layer may comprise between 2 and 20% by weight fibres on a dry weight basis. Alternatively, the fibers are cellulosic fibers. Advantageously, the cellulose fibers are not too expensive and can increase the tensile strength of the matrix.

Optionally, each of the fibers has three mutually perpendicular dimensions, the largest dimension of the three dimensions being at least 1.5, 2, 3, 5, 10, or 20 times the smallest dimension of the three dimensions. Optionally, each of the fibers has three mutually perpendicular dimensions, the largest dimension of the three dimensions being at least 1.5, 2, 3, 5, 10, or 20 times the second largest dimension of the three dimensions.

The reconstituted carbon-based material may include a binder. The reconstituted carbon-based material may comprise between 2 and 10% by weight binder on a dry weight basis. Optionally, the matrix comprises at least 4, 6 or 8 wt% binder on a dry weight basis. Optionally, the matrix comprises no more than 8, 6 or 4 wt% binder on a dry weight basis. Optionally, the matrix comprises between 4 and 10 wt%, 6 and 10 wt%, 8 and 10 wt%, 2 and 8 wt%, 4 and 8 wt%, 6 and 8 wt%, 2 and 6 wt%, 4 and 6 wt%, 2 and 4 wt%, based on dry weight. It may be particularly preferred for the matrix to include between 2.1 and 10 wt% binder on a dry weight basis.

Suitable binders are well known in the art and include, but are not limited to, natural pectins, such as fruit, citrus or tobacco pectins; guar gums, such as hydroxyethyl guar and hydroxypropyl guar; locust bean gums, such as hydroxyethyl and hydroxypropyl locust bean gums; an alginate; starches, such as modified starches or derivatized starches; cellulose, such as methyl cellulose, ethyl hydroxymethyl cellulose, and carboxymethyl cellulose; tamarind gum; dextran; pralan (pulullon); konjaku flour; xanthan gum, and the like. Especially preferred for the binder may be guar gum or include guar gum. It may be particularly preferred for the binder to include or consist of one or more of carboxymethyl cellulose or hydroxypropyl cellulose or a gum such as guar gum.

Optionally, the thermally conductive particles are substantially uniformly distributed throughout the layer of thermally conductive material. Optionally, the aerosol former is substantially uniformly distributed throughout the layer of thermally conductive material. Optionally, the fibers are substantially uniformly distributed throughout the layer of thermally conductive material. Optionally, the binder is substantially uniformly distributed throughout the layer of thermally conductive material. Advantageously, a uniform distribution of the components of the matrix may result in a matrix having more spatially uniform properties. For example, a substantially uniform distribution of thermally conductive particles may provide a matrix with a substantially uniform thermal conductivity. As another example, a substantially uniform distribution of binder or fibers may provide a matrix with substantially uniform tensile strength.

Advantageously, one or both of the fibers and the binder may increase the tensile strength of the heavy structural carbon-based material. The increased tensile strength may allow for the production of sheets of reconstituted carbon-based material that are not easily torn. The increased tensile strength may allow for the production of reconstituted carbon-based materials using existing production machinery.

The thermally conductive particles may each have a "particle size". The meaning of the term "particle size" and the method of measuring particle size are set forth later.

The thermally conductive particles may be characterized by a particle size distribution. The particle size distribution may have a number D10, a number D50 and a number D90 particle size. The number D10 particle size is defined as 10% of the particles having a particle size less than or equal to the number D10 particle size. Similarly, the number D50 particle size is defined as 50% of the particles having a particle size less than or equal to the number D50 particle size. Thus, the number D50 of particle sizes may be referred to as the median particle size. The number D90 particle size is defined as 90% of the particles having a particle size less than or equal to the number D90 particle size. Thus, if there are 1,000 particles in the distribution and the particles are ordered in ascending order of particle size, then the expected number D10 of particles sizes is approximately equal to the 100 th particle size, the number D50 of particles sizes is approximately equal to the 500 th particle size, and the number D90 of particles sizes is approximately equal to the 900 th particle size.

The particle size distribution may have volume D10, D50 and D90 particle sizes. The volume D10 particle size is defined as the sum of the volumes of particles having a particle size less than or equal to the volume D10 particle size accounting for 10% of the sum of the volumes of all particles. Similarly, the volume D50 particle size is defined as the sum of the volumes of particles having a particle size less than or equal to the volume D50 particle size accounting for 50% of the sum of the volumes of all particles. And, the volume D90 particle size is defined as the sum of the volumes of particles having a particle size less than or equal to the volume D90 particle size accounting for 90% of the sum of the volumes of all particles.

Optionally, the particle size distribution of the thermally conductive particles has a number D10 of particle sizes, wherein the number D10 of particle sizes is at least 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 microns.

Optionally, the particle size distribution of the thermally conductive particles has a number D10 of particle sizes, wherein the number D10 of particle sizes does not exceed 1,000, 500, 200, 100, 50, 20, 10, 5, 2, 1, 0.5, or 0.2 microns.

In determining the particle size, a compromise must be made. The larger thermally conductive particles may advantageously increase the thermal conductivity of the reconstituted carbon based material compared to the smaller thermally conductive particles, and thus the thermal conductivity of the aerosol-forming substrate comprising the reconstituted carbon based material. However, larger thermally conductive particles may reduce the space available for aerosol-forming material in the matrix.

Optionally, the particle size distribution of the thermally conductive particles has a number D50 particle size, wherein the number D50 particle size is at least 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 microns.

Optionally, the particle size distribution of the thermally conductive particles has a number D50 particle size, wherein the number D50 particle size does not exceed 1,000, 500, 200, 100, 50, 20, 10, 5, 2, 1, 0.5, or 0.2 microns.

Optionally, the particle size distribution of the thermally conductive particles has a number D90 particle size, wherein the number D90 particle size is at least 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 microns.

Optionally, the particle size distribution of the thermally conductive particles has a number D90 particle size, wherein the number D90 particle size does not exceed 1,000, 500, 200, 100, 50, 20, 10, 5, 2, 1, 0.5, or 0.2 microns.

Optionally, the particle size distribution of the thermally conductive particles has a number D10 particle size and a number D90 particle size, wherein the number D90 particle size is no more than 50, 40, 30, 20, 10 or 5 times the number D10 particle size.

Optionally, the particle size distribution of the thermally conductive particles has a number D10 particle size and a number D90 particle size, wherein the number D90 particle size is at least 1.5, 2, 3, 5, 10, or 20 times the number D10 particle size.

A compromise must be made with respect to the particle size distribution. A tighter particle size distribution (e.g., characterized by a smaller ratio between D90 and D10 particle sizes) can advantageously provide a more uniform thermal conductivity throughout the reconstituted carbon-based material. This is because the particle size changes less at different locations in the matrix. This may advantageously allow for more efficient use of the aerosol-forming material throughout the aerosol-forming substrate. Disadvantageously, however, tighter particle size distributions may be more difficult and expensive to achieve. The inventors have found that the above particle size distribution provides the best compromise between these two factors.

Optionally, the particle size distribution of the thermally conductive particles has a volume D10 particle size, wherein the volume D10 particle size is at least 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 microns.

Optionally, the particle size distribution of the thermally conductive particles has a volume D10 particle size, wherein the volume D10 particle size does not exceed 1,000, 500, 200, 100, 50, 20, 10, 5, 2, 1, 0.5, or 0.2 microns.

Optionally, the particle size distribution of the thermally conductive particles has a volume D50 particle size, wherein the volume D50 particle size is at least 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 microns.

Optionally, the particle size distribution of the thermally conductive particles has a volume D50 particle size, wherein the volume D50 particle size is no more than 1,000, 500, 200, 100, 50, 20, 10, 5, 2, 1, 0.5, or 0.2 microns.

Optionally, the particle size distribution of the thermally conductive particles has a volume D90 particle size, wherein the volume D90 particle size is at least 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 microns.

Optionally, the particle size distribution of the thermally conductive particles has a volume D90 particle size, wherein the volume D90 particle size does not exceed 1,000, 500, 200, 100, 50, 20, 10, 5, 2, 1, 0.5, or 0.2 microns.

The thermally conductive particles may particularly preferably have a particle size distribution with a volume D10 particle size between 1 and 20 micrometers. Alternatively or additionally, the thermally conductive particles may particularly preferably have a particle size distribution with a volume D90 particle size between 50 and 300 micrometers or between 50 and 200 micrometers.

Optionally, the particle size distribution of the thermally conductive particles has a volume D10 particle size and a volume D90 particle size, wherein the volume D90 particle size is no more than 50, 40, 30, 20, 10 or 5 times the volume D10 particle size.

Optionally, the particle size distribution of the thermally conductive particles has a volume D10 particle size and a volume D90 particle size, wherein the volume D90 particle size is at least 1.5, 2, 3, 5, 10, or 20 times the volume D10 particle size.

As explained above, a compromise must be made with respect to the particle size distribution, and the inventors have found that the above particle size distribution can provide the best compromise.

Optionally, each of the thermally conductive particles has a particle size of at least 0.01, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 microns. Optionally, each of the thermally conductive particles has a particle size of no more than 1,000, 500, 300, 200, 100, 50, 20, 10, 5, 2, 1, 0.5, or 0.2 microns. It may be particularly preferred for each of the thermally conductive particles to have a particle size of at least 1 micron. Alternatively or additionally, it may be particularly preferable for each of the thermally conductive particles to have a particle size of no more than 300 microns. Particles smaller than 1 micron may be difficult to handle during manufacturing. Particles larger than 300 microns may occupy a significant amount of space in the matrix that is available for aerosol-forming materials. Thus, each of the thermally conductive particles may particularly advantageously have a particle size of at least 1 micron or a particle size of no more than 300 microns or both.

Optionally, each of the thermally conductive particles has three mutually perpendicular dimensions, a largest dimension of the three dimensions not exceeding 10, 8, 5, 3 or 2 times a smallest dimension of the three dimensions. Optionally, each of the thermally conductive particles has three mutually perpendicular dimensions, a largest dimension of the three dimensions not exceeding 10, 8, 5, 3 or 2 times a second largest dimension of the three dimensions. Optionally, each of the thermally conductive particles is substantially spherical. Advantageously, the orientation of the substantially spherical particles may not affect the thermal conductivity of the matrix as does the orientation of the non-spherical particles. Thus, in cases where the orientation of the particles is not controlled, the use of more spherical particles may result in less variability between different matrices. In addition, substantially spherical particles may be more easily characterized.

Optionally, the thermally conductive particles comprise at least 10, 20, 50, 100, 200, 500, or 1000 particles. Advantageously, a greater number of particles in the aerosol-forming substrate may result in a more uniform thermal conductivity of the substrate.

Optionally, the matrix comprises at least 20, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85 weight percent thermally conductive particles on a dry weight basis. Optionally, the matrix comprises no more than 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, or 15 weight percent thermally conductive particles on a dry weight basis. Alternatively, the matrix comprises between 10 and 90 wt%, 20 and 90 wt%, 30 and 90 wt%, 40 and 90 wt%, 50 and 90 wt%, 60 and 90 wt%, 70 and 90 wt%, 80 and 90 wt%, 10 and 80 wt%, 20 and 80 wt%, 30 and 80 wt%, 40 and 80 wt%, 50 and 80 wt%, 60 and 80 wt%, 70 and 80 wt%, 10 and 70 wt%, 20 and 70 wt%, 30 and 70 wt%, 40 and 70 wt%, 50 and 70 wt%, 60 and 70 wt%, 10 and 60 wt%, 20 and 60 wt%, 30 and 60 wt%, 40 and 60 wt%, 50 and 60 wt%, 10 and 50 wt%, 30 and 50 wt%, 40 and 50 wt%, 10 and 40 wt%, 20 and 40 wt%, 30 and 40 wt%, 10 and 30 wt%, 20 and 30 wt%, or 10 and 20 wt% of thermally conductive particles on a dry basis. It may be particularly preferred for the matrix to comprise between 50 and 90 wt.%, or more preferably between 60 and 90 wt.%, or even more preferably between 65 and 85 wt.% of thermally conductive particles on a dry weight basis.

A compromise must be made regarding the weight percentage of thermally conductive particles in the matrix. Increasing the weight percent of particles in the aerosol-forming substrate may advantageously increase the thermal conductivity of the substrate. However, increasing the weight percent of particles in the aerosol-forming substrate may also reduce the available space for one or more of the aerosol-former, binder, and fibers, thus may allow the substrate to form less aerosol or have less tensile strength.

The carbon-based thermally conductive material layer does not include tobacco. The carbon-based thermally conductive material layer may not include nicotine.

The carbon-based thermally conductive material layer may be formed by a casting process.

The co-laminate sheet may comprise or have the form of an aggregate sheet. The carbon-based thermally conductive material may have sufficient tensile strength to withstand the aggregation process while providing support for the aerosol-forming material layer.

The carbon-based thermally conductive material layer may have a thermal conductivity greater than 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000, or 1500W/(mK). The thermal conductivity may be as measured at 25 ℃.

The carbon-based thermally conductive material layer may exhibit anisotropic thermal conductivity. The carbon-based thermally conductive material layer may lie in a plane or define a plane. The in-plane carbon-based thermally conductive material layer may have a thermal conductivity greater than 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000, or 1500W/mK. The thermal conductivity may be as measured at 25 ℃.

Advantageously, increasing the thermal conductivity of the layer of thermally conductive material may increase the thermal conductivity of the aerosol-forming substrate.

The expanded graphite may have a particle size of less than 2, 1.8, 1.5, 1.2, 1, 0.8 or 0.5, 0.2, 0.1, 0.05, 0.02 grams per cubic centimeter (g/cm) ³ ) Is a density of (3).

The expanded graphite may have a particle size of greater than 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 0.8, 1, 1.2, 1.5, or 1.8 grams/cubic centimeter (g/cm) ³ ) Is a density of (3).

The expanded graphite may have a density of 0.01 to 3, 0.01 to 2, 0.01 to 1.8, 0.01 to 1.5, 0.01 to 1.2, 0.01 to 1, 0.01 to 0.8, 0.01 to 0.5, 0.02 to 3, 0.02 to 2, 0.02 to 1.8, 0.02 to 1.5, 0.02 to 1.2, 0.02 to 1, 0.02 to 0.8, 0.02 to 0.5, 0.01 to 3, 0.05 to 2, 0.05 to 1.8, 0.05 to 1.5, 0.05 to 1.2, 0.05 to 1, 0.05 to 0.8, 0.05 to 0.5g/cm ³ 0.1 and 3, 0.1 and 2, 0.1 and 1.8, 0.1 and 1.5, 0.1 and 1.2, 0.1 and 1, 0.1 and 0.8, 0.1 and 0.5, 0.2 and 3, 0.2 and 2, 0.2 and 1.8, 0.2 and 1.5, 0.2 and 1.2, 0.2 and 1, 0.2 and 0.8, 0.2 and 0.5, 0.5 and 3, 0.5 and 2, 0.5 and 1.8, 0.5 and 1.5, 0.5 and 1.2, 0.5 and 1, 0.8 and 0.8, 0.8 and 2, 0.8 and 1.8, 0.8 and 1.5, 0.8 and 1.2, 0.8 and 1 g/cc (g/cm) ³ ) Density of the two.

The carbon-based thermally conductive material layer may include greater than 10%, 30%, 50%, 70%, 80%, 90%, 95%, 98%, 99%, 99.5%, or 99.9% carbon by weight. The carbon-based thermally conductive material layer may be composed of carbon other than trace impurities.

The carbon-based thermally conductive material layer may comprise less than or equal to 90, 80, 70, 60, 50, 20, 10, or 5 wt% of the aerosol-forming substrate. The carbon-based thermally conductive material layer may comprise greater than or equal to 0.1, 0.2, 0.5, 1, 2, 3, 5, 10, 20, 30, 40, or 50 wt% of the aerosol-forming substrate. The carbon-based thermally conductive material layer may comprise 20 to 90 wt%, 30 to 90 wt%, 40 to 90 wt%, 20 to 80 wt%, 30 to 80 wt%, 40 to 80 wt%, 20 to 70 wt%, 30 to 70 wt%, 40 to 70 wt%, 20 to 60 wt%, 30 to 60 wt%, 40 to 60 wt%, 20 to 50 wt%, 30 to 50 wt% of the aerosol-forming substrate.

Advantageously, the inventors have found that such weight percentages provide the best compromise between increasing the thermal conductivity of the aerosol-forming substrate and maintaining sufficient aerosol-forming material to form a sufficient amount of aerosol.

The aerosol-forming material layer may have a thermal conductivity between 0.1W/mK and 0.2W/mK. This may be the case if the aerosol-forming material is standard homogenized tobacco. Thus, in some embodiments, the aerosol-forming material may have a thermal conductivity of less than 0.2W/mK, for example, when measured at 25 ℃, and the carbon-based thermally conductive material layer may have a thermal conductivity of greater than 0.22W/mK, and preferably much greater, for example, when measured at 25 ℃. The carbon-based thermally conductive material layer may have a thermal conductivity in its planar direction of up to 1700W/mK, as found, for example, in commercial graphite foils.

These thermal conductivities can be measured when the moisture content of the material is between 0% and 20% or between 5% and 15%, for example about 10%. This thermal conductivity can be measured when the material comprises 0 to 20 wt% or 5 to 15 wt% water, for example about 10 wt%. The moisture or water content of the material can be measured using titration methods. The moisture or water content of a material can be measured using the Karl fischer (Karl Fisher) method.

The aerosol-forming material is preferably configured to generate an aerosol upon heating, for example, to a temperature between 120 degrees celsius and 395 degrees celsius. In some embodiments, the carbon-based thermally conductive material layer is not configured to generate an aerosol when heated, for example, when heated to a temperature between 120 degrees celsius and 350 degrees celsius. Thus, in these embodiments, the carbon-based thermally conductive material layer is not an aerosol-forming material. The role of the carbon-based thermally conductive material in such embodiments is to facilitate the transfer of heat to allow for optimizing aerosol generation from the aerosol-forming material.

The aerosol-forming material may comprise one or more organic materials, such as tobacco. The aerosol-forming substrate may comprise one or more of the following: herb leaves, tobacco vein segments, reconstituted tobacco, homogenized tobacco, extruded tobacco and expanded tobacco. Preferably, the aerosol-forming material may be formed from homogenized tobacco. Preferably, the aerosol-forming material comprises tobacco and an aerosol-former. Preferably, the aerosol-forming material is configured to generate an aerosol when heated to a temperature between 120 degrees celsius and 395 degrees celsius. The aerosol-forming material may be a homogenized tobacco material comprising an aerosol-forming agent such as glycerin or propylene glycol. The first material may also include fibers and a binder to improve the structure of the first material.

Advantageously, one or both of the fibers and the binder may increase the tensile strength of the aerosol-forming material. The increased tensile strength may allow for the production of co-laminated sheets of aerosol-forming substrates that are not easily torn. The increased tensile strength may allow for the production of co-laminated sheets of aerosol-forming substrates using existing production machinery.

The aerosol-forming material may comprise one or more aerosol-formers. Suitable aerosol formers are well known in the art and include, but are not limited to, one or more aerosol formers selected from the group consisting of: polyhydric alcohols such as propylene glycol, polyethylene glycol, triethylene glycol, 1, 3-butanediol, and glycerol; esters of polyhydric alcohols, such as monoacetin, diacetin or triacetin; and aliphatic esters of mono-, di-or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Particularly preferred for the aerosol former may be or include glycerol. Optionally, the aerosol-forming substrate comprises one or both of glycerol and glycerin.

Optionally, the matrix comprises at least 10, 15, 20, 25, 30, 35, 40, 45, 50 or 55 wt% aerosol former on a dry weight basis. Optionally, the matrix comprises no more than 55, 50, 45, 40, 35, 30, 25, 20 or 15 wt% aerosol former on a dry weight basis. Alternatively, the matrix comprises between 7 and 60 wt%, 10 and 60 wt%, 20 and 60 wt%, 30 and 60 wt%, 40 and 60 wt%, 50 and 60 wt%, 7 and 50 wt%, 10 and 50 wt%, 20 and 50 wt%, 30 and 50 wt%, 40 and 50 wt%, 7 and 40 wt%, 10 and 40 wt%, 20 and 40 wt%, 30 and 40 wt%, 7 and 30 wt%, 10 and 30 wt%, 20 and 30 wt%, 7 and 20 wt%, 10 and 20 wt% or 7 and 10 wt% of the aerosol former on a dry weight basis. It may be particularly preferred for the matrix to include between 15 and 25 wt% aerosol former on a dry weight basis.

Optionally, the matrix comprises at least 2, 4, 6, 8, 10, 12, 14, 16 or 18 weight percent fibers on a dry weight basis. Optionally, the matrix comprises no more than 20, 18, 16, 14, 12, 10, 8, 6 or 4 weight percent fibers on a dry weight basis. Alternatively, the matrix comprises between 4 and 20 wt%, 6 and 20 wt%, 8 and 20 wt%, 10 and 20 wt%, 12 and 20 wt%, 14 and 20 wt%, 16 and 20 wt%, 18 and 20 wt%, 2 and 18 wt%, 4 and 18 wt%, 6 and 18 wt%, 8 and 18 wt%, 10 and 18 wt%, 12 and 18 wt%, 14 and 18 wt%, 16 and 18 wt%, 2 and 16 wt%, 4 and 16 wt%, 6 and 16 wt%, 8 and 16 wt%, 10 and 16 wt%, 12 and 16 wt%, 14 and 16 wt%, 2 and 14 wt%, 4 and 14 wt%, 6 and 14 wt%, 8 and 14 wt%, 10 and 14 wt%, 12 and 14 wt%, 2 and 12 wt%, 4 and 12 wt%, 6 and 12 wt%, 8 and 12 wt%, 10 and 12 wt%, 2 and 10 wt%, 4 and 10 wt%, 6 and 10 wt%, 2 and 8 wt%, 4 and 8 wt%, 6 and 8 wt%, 2 and 6 wt%, 6 wt% and 6 wt%, or 4 wt% and 4 wt% of fibers on a dry basis. It may be particularly preferred for the matrix to include between 2.1 and 9.8 weight percent fibers on a dry weight basis.

The aerosol former may be glycerol. The aerosol-forming substrate may comprise at least 1, 2, 5, 10 or 15% by weight of glycerol. For example, the aerosol-forming substrate may comprise between 12 and 25 wt% glycerol.

The aerosol-forming material may comprise fibres, preferably between 2 and 20% by weight fibres. The aerosol-forming material may comprise a binder, preferably between 2 and 10% by weight of the binder.

Alternatively, the fibers are cellulosic fibers. Advantageously, the cellulose fibers are not too expensive and can increase the tensile strength of the matrix.

Optionally, the matrix comprises at least 4, 6 or 8 wt% binder on a dry weight basis. Optionally, the matrix comprises no more than 8, 6 or 4 wt% binder on a dry weight basis. Optionally, the matrix comprises between 4 and 10 wt%, 6 and 10 wt%, 8 and 10 wt%, 2 and 8 wt%, 4 and 8 wt%, 6 and 8 wt%, 2 and 6 wt%, 4 and 6 wt%, 2 and 4 wt%, based on dry weight. It may be particularly preferred for the matrix to include between 2.1 and 10 wt% binder on a dry weight basis.

The aerosol-forming material may comprise nicotine. Alternatively, the aerosol-forming substrate comprises at least 0.01, 1, 2, 3 or 4% by weight nicotine on a dry weight basis. Optionally, the aerosol-forming substrate comprises no more than 5, 4, 3, 2 or 1% by weight nicotine on a dry weight basis. Alternatively, the aerosol-forming substrate comprises between 0.01 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 3 and 5 wt%, 4 and 5 wt%, 0.01 and 4 wt%, 1 and 4 wt%, 2 and 4 wt%, 3 and 4 wt%, 0.01 and 3 wt%, 1 and 3 wt%, 2 and 3 wt%, 0.01 and 2 wt%, 1 and 2 wt%, 0.01 and 1 wt% nicotine on a dry weight basis. It may be particularly preferred for the aerosol-forming substrate to comprise between 0.5 and 3% by weight nicotine on a dry weight basis.

Alternatively, the nicotine is substantially uniformly distributed throughout the aerosol-forming material.

Optionally, the aerosol-forming material comprises an acid. Alternatively, the aerosol-forming substrate comprises at least 0.01, 1, 2, 3 or 4 wt% acid on a dry weight basis. Optionally, the aerosol-forming substrate comprises no more than 5, 4, 3, 2 or 1 wt% acid on a dry weight basis. Alternatively, the aerosol-forming substrate comprises between 0.01 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 3 and 5 wt%, 4 and 5 wt%, 0.01 and 4 wt%, 1 and 4 wt%, 2 and 4 wt%, 3 and 4 wt%, 0.01 and 3 wt%, 1 and 3 wt%, 2 and 3 wt%, 0.01 and 2 wt%, 1 and 2 wt%, 0.01 and 1 wt% of an acid on a dry weight basis. It may be particularly preferred for the aerosol-forming substrate to comprise between 0.5 and 3% by weight of acid on a dry weight basis.

Alternatively, the acid comprises or consists of one or more of fumaric acid, lactic acid, benzoic acid and levulinic acid.

Alternatively, the acid is substantially uniformly distributed throughout the aerosol-forming material.

Optionally, the aerosol-forming material comprises at least one botanical formulation. Optionally, the matrix comprises at least 0.01, 1, 2, 5, 10 or 15 wt% of the at least one plant preparation on a dry weight basis. Optionally, the matrix comprises no more than 20, 15, 10, 5, 2 or 1 wt% of the at least one plant preparation on a dry weight basis. Optionally, the matrix comprises between 0.01 and 20, 1 and 20, 2 and 20, 5 and 20, 10 and 20, 15 and 20, 0.01 and 15, 1 and 15, 2 and 15, 5 and 15, 10 and 15, 0.01 and 10, 1 and 10, 2 and 10, 5 and 10, 0.01 and 5, 1 and 5, 2 and 5, 0.01 and 2, 1 and 2, 0.01 and 1% by weight on a dry weight basis of at least one botanical preparation. It may be particularly preferred for the matrix to comprise between 5 and 15% by weight of at least one vegetable preparation on a dry weight basis.

Optionally, the at least one botanical preparation comprises or consists of one or both of clove and 16omprise16 s.

Optionally, the at least one botanical agent is substantially uniformly distributed throughout the aerosol-forming material.

Optionally, the aerosol-forming material comprises at least one flavour. Optionally, the aerosol-forming substrate comprises at least 0.1, 1, 2 or 5 wt% of at least one perfume on a dry weight basis. Optionally, the aerosol-forming substrate comprises not more than 10, 5, 2 or 1 wt% of at least one perfume on a dry weight basis. Optionally, the aerosol-forming substrate comprises between 0.1 and 10 wt%, 1 and 10 wt%, 2 and 10 wt%, 5 and 10 wt%, 0.1 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 0.1 and 2 wt%, 1 and 2 wt%, 0.1 and 1 wt% of at least one perfume on a dry weight basis. It may be particularly preferred for the matrix to comprise between 0.5 and 4.0 wt.% of at least one perfume on a dry weight basis.

Optionally, the at least one fragrance is present as a coating, e.g. a coating on one or more other components of the aerosol-forming substrate. Alternatively or additionally, the at least one fragrance is substantially uniformly distributed throughout the aerosol former.

Optionally, the aerosol-forming material comprises at least one organic material, such as tobacco. Optionally, the at least one organic material comprises one or more of: herb leaves, tobacco vein segments, reconstituted tobacco, homogenized tobacco, extruded tobacco and expanded tobacco. Optionally, the at least one organic material is substantially uniformly distributed throughout the aerosol-forming material.

The aerosol-forming substrate may comprise less than 10, 5, 3, 2 or 1% by weight tobacco on a dry weight basis. Alternatively, the aerosol-forming substrate is a tobacco-free aerosol-forming substrate.

The aerosol-forming material may comprise one or more sheets (e.g. one or more gathered sheets), or may be in the form of one or more sheets. The or each sheet (e.g. gathered sheet) may have a width of at least about 10, 25, 50 or 100 mm. The or each sheet (e.g. gathered sheet) may have a length of at least about 3, 5 or 10 mm. The or each sheet (e.g. the aggregate sheet) may have a thickness of at least about 100, 150 or 200 microns. The or each sheet (e.g. the aggregate sheet) may have a thickness of less than about 500, 400 or 300 microns. The or each sheet (e.g. the aggregate sheet) may have a thickness of between 100 and 500 microns, between 170 and 400 microns or between 200 and 300 microns. The or each sheet (e.g. the aggregate sheet) may have a thickness of about 235 microns.

According to a second aspect, a bar is provided. The strip may be a strip for an aerosol-generating article. The strip may comprise or be formed from an aerosol-forming substrate. In other words, a strip of aerosol-forming substrate may be provided. The strip may comprise an aggregated sheet of aerosol-forming substrate.

The strip may comprise a wrapper of gathered sheet material defining an aerosol-forming substrate. Preferably, the aerosol-forming substrate is an aerosol-forming substrate according to the first aspect. Thus, the strip may be formed by gathering the co-laminated sheets of the first aspect.

The susceptor element may be located within a strip of aerosol-forming substrate. The susceptor element may be an elongated susceptor element. The susceptor element may extend longitudinally within the strip of aerosol-forming substrate. The shape of the strip may be substantially cylindrical, for example right cylindrical. The susceptor element may be positioned at a radial central position within the strip of aerosol-forming substrate. The susceptor element may extend along a central longitudinal axis of the strip of aerosol-forming substrate.

The susceptor element may extend all the way to the downstream end of the strip of aerosol-forming substrate. The susceptor element may extend all the way to the upstream end of the strip of aerosol-forming substrate. The susceptor element may have substantially the same length as the strip of aerosol-forming substrate. The susceptor element may extend from an upstream end to a downstream end of the strip of aerosol-forming substrate.

The susceptor element may be in the form of a needle, a strip or a blade.

The susceptor element may have a length of between 5 and 15 mm, 6 and 12 mm or 8 and 10 mm. The susceptor element may have a width of between 1 and 5 mm. The susceptor element may have a thickness of between 0.01 and 2 mm, 0.5 and 2 mm or 0.5 and 1 mm.

Alternatively, no susceptor material may be present in the aerosol-forming substrate or in the strip of aerosol-forming substrate. Alternatively, the carbon-based heat conductive material layer may comprise or consist of one or more susceptor materials, and may be the only susceptor material present in the aerosol-forming substrate or in a strip of the aerosol-forming substrate. That is, no susceptor element may be present in the aerosol-forming substrate or in the strip of aerosol-forming substrate other than the layer of thermally conductive material.

Suitable susceptor materials, such as materials for susceptor elements, include, but are not limited to: carbon, carbon-based materials, graphene, graphite, expanded graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel-containing compounds, titanium, and composites of metallic materials. Suitable susceptor materials may include ferromagnetic materials (e.g., ferritic iron), ferromagnetic alloys (e.g., ferromagnetic steel or stainless steel), ferromagnetic particles, and ferrites. Suitable susceptor materials may be or include aluminum. The susceptor material preferably comprises more than 5%, preferably more than 20%, more preferably more than 50% or more than 90% of ferromagnetic or paramagnetic material. Preferred susceptor materials may include metals, metal alloys, or carbon.

Particularly preferred susceptor materials may be or include carbon, carbon-based materials, graphene, graphite or expanded graphite. Advantageously, such materials have relatively high thermal conductivity, relatively low density, and can be inductively heated. These materials may be preferred when the carbon-based thermally conductive material layer acts as a susceptor or comprises a material that acts as a susceptor.

As will be explained in more detail later with reference to the aerosol-generating system, in use, the susceptor material may convert electromagnetic energy into thermal energy. This may heat the aerosol-forming material of the aerosol-forming substrate.

The aerosol-forming substrate may have a longitudinal direction and a transverse or radial direction perpendicular to the longitudinal direction. For example, the aerosol-forming substrate may be in the form of a rod. The shape of the rod may be a right cylinder. The rod may have a length extending in a longitudinal direction and a radius extending in a transverse or radial direction. The longitudinal direction may refer to a direction extending from an upstream end to a downstream end of the substrate, or a direction extending from an upstream end to a downstream end of an article of which the substrate is a part. The aerosol-forming substrate may have a thermal conductivity of greater than 0, 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.75, 1, 1.25, 1.5, 2, 5, 10, 20, 50, 100, 200, or 500W/(mK) at 25 degrees celsius in at least one direction.

Advantageously, increasing the thermal conductivity of the matrix may reduce the temperature gradient of the matrix in use. Increasing the thermal conductivity of the matrix in the lateral direction may be particularly advantageous because there is typically a large temperature gradient in the lateral direction in the prior art matrix when it is used with a heating blade.

According to a third aspect of the present disclosure there is provided an aerosol-generating article comprising an aerosol-forming substrate. Any of the features described above in relation to an aerosol-forming substrate may be applied to an aerosol-forming substrate of an aerosol-generating article.

The aerosol-generating article may be used with an electric aerosol-generating device.

The aerosol-generating substrate may comprise a plurality of elements. The plurality of elements may be assembled in the form of a strip. The plurality of elements may be assembled within a package or housing. The aerosol-generating article may have a length of between 30mm and 120mm, for example between 40mm and 80mm, for example about 45 mm. The aerosol-generating article may have a diameter of between 3.5mm and 10mm, for example between 4mm and 8.5mm, for example between 4.5mm and 7.5 mm.

The plurality of elements may include an upstream element. The plurality of elements may comprise an aerosol-forming substrate. The plurality of elements may comprise support elements. The plurality of elements may include an aerosol-cooling element. The plurality of elements may comprise mouthpiece elements.

The aerosol-generating article may comprise an intermediate hollow section. The intermediate hollow section may be located between the strip of aerosol-generating substrate and the mouthpiece element. The intermediate hollow section may include one or both of a support element and an aerosol-cooling element. The intermediate hollow section may be constituted by one or both of a support element and an aerosol-cooling element.

The upstream element may be located at an upstream end of the article. The aerosol-forming substrate may be located downstream of the upstream element, for example immediately downstream. Alternatively, the aerosol-forming substrate may be located at the upstream end of the article, for example in the absence of an upstream element. The support element may be located downstream of the aerosol-forming substrate, for example immediately downstream. The aerosol-cooling element may be located downstream of the support element, for example immediately downstream. The mouthpiece element may be located downstream of the aerosol-cooling element, for example immediately downstream. The mouthpiece element may be located at the downstream or mouth end of the article.

The upstream element may advantageously prevent direct physical contact with the upstream end of the aerosol-forming substrate. The upstream element may also advantageously reduce the likelihood of material from the aerosol-forming substrate falling out of the article. The support element may advantageously provide support for the article and help to properly position other components of the article. The aerosol-cooling element may advantageously allow the aerosol to cool such that when the aerosol reaches the user, the aerosol is a more desirable temperature. The mouthpiece element may advantageously act as a filter.

The various elements of the aerosol-generating article may be assembled by means of a suitable wrapper (e.g. cigarette paper). The wrapper may be any suitable material for wrapping the components of the aerosol-generating article in the form of a rod. Suitable materials for the wrapper are well known in the art. When the article is assembled, the cigarette paper may grip the component elements of the aerosol-generating article. The cigarette paper may hold the component elements in place within the rod.

The upstream element may be in the form of a rod, for example a porous rod. The upstream element may comprise one or more longitudinally extending cavities. The upstream element may comprise a slit or an orifice. The slit or aperture may extend from the upstream end to the downstream end of the upstream element. The slit or aperture may be adapted to allow a heated needle, strip or blade to pass therethrough in use. The upstream element may be made of a porous material. The upstream element may be made of the same material as the material used for one of the other components of the aerosol-generating article (e.g. the mouthpiece element, the aerosol-cooling element or the support element). The upstream element may comprise or be formed from one or more of a filter material, ceramic, polymeric material, cellulose acetate, cardboard, zeolite or an aerosol-generating substrate. It may be preferred that the upstream element comprises or is formed from cellulose acetate (e.g. a filter segment of cellulose acetate).

Alternatively, the front bar has a length of between 2 and 10mm, 3 and 8mm or 4 and 6mm, for example about 5 mm. Alternatively, the aerosol-forming substrate within the article has a length of between 5 and 20mm, 8 and 15mm or 10 and 15mm, for example about 12 mm.

The upstream element may have a length of between 1 and 10mm, 3 and 8mm or 4 and 6 mm. The upstream element may have a length of about 5 millimeters.

Advantageously, the upstream element may prevent a consumer from viewing the layer of thermally conductive material through the upstream end of the article.

The support element may comprise or may be a hollow tube, for example a substantially cylindrical hollow tube. The hollow tube may define an inner lumen. The lumen may extend in a longitudinal direction. The flow of air through the lumen may be substantially unrestricted. Thus, the hollow tube may contribute substantially no Resistance To Draw (RTD) of the article. The wall of the hollow tube may have a thickness of between 2 and 4 mm.

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, curled papers, such as curled heat resistant papers or curled parchment papers, and polymeric materials, such as Low Density Polyethylene (LDPE). In a preferred embodiment, the support element is formed from cellulose acetate. Other suitable materials include Polyhydroxyalkanoate (PHA) fibers. It may be particularly preferred that the support element comprises or is formed from cellulose acetate.

The support element may have an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The support element may have an outer diameter of between 5 and 12 mm, between 5 and 10 mm or between 5 and 8 mm, between 6 and 12 mm, between 6 and 10 mm or between 6 and 8 mm. The support element may have an outer diameter of about 7.2 millimeters.

The peripheral wall of the support element may have a thickness of at least 1, 1.5 or 2 mm, for example in case the support element comprises or is a second hollow tube.

The support element may have a length of at least 5, 6, 7 or 8 mm. Alternatively or additionally, the support element may have a length of less than 15, 12 or 10 millimeters.

The aerosol-cooling element may comprise or may be a second hollow tube, for example a substantially cylindrical second hollow tube. The second hollow tube may define a second lumen. The second lumen may extend in a longitudinal direction. The flow of air through the second lumen may be substantially unrestricted. Thus, the second hollow tube may not contribute substantially to the suction Resistance (RTD) of the article. The wall of the second hollow tube may have a thickness of between 1 and 3 millimeters.

The aerosol-cooling element may comprise or be formed of any suitable material or combination of materials. For example, the aerosol-cooling element may comprise or be formed from one or more materials selected from: cellulose acetate, cardboard, curled papers, such as curled heat resistant papers or curled parchment papers, and polymeric materials, such as Low Density Polyethylene (LDPE). Other suitable materials include Polyhydroxyalkanoate (PHA) fibers. It may be preferred that the aerosol-cooling element comprises or is formed from cellulose acetate.

The aerosol-cooling element may have an outer diameter that is approximately equal to an outer diameter of the aerosol-generating article. The aerosol-cooling element may have an outer diameter of between 5 and 12 mm, 5 and 10 mm or 5 and 8 mm, 6 and 12 mm, 6 and 10 mm or 6 and 8 mm. The aerosol-cooling element may have an outer diameter of about 7.2 millimeters.

The aerosol-cooling element may have an inner diameter of at least about 2, 2.5 or 3 millimeters, for example in the case where the aerosol-cooling element comprises or is a second hollow tube.

The peripheral wall of the aerosol-cooling element may have a thickness of less than about 2.5, 1.5, 1.25, 1, 0.9 or 0.8 millimeters, for example in the case where the aerosol-cooling element comprises or is a second hollow tube.

The aerosol-cooling element may have a length of at least 5, 6, 7 or 8 millimeters. Alternatively or additionally, the aerosol-cooling element may have a length of less than 15, 12 or 10 millimeters.

The mouthpiece element may comprise a filter material, such as a fibrous filter material. The mouthpiece element may comprise or may be a cellulose acetate filter segment. The mouthpiece element may be translucent or opaque.

The mouthpiece element may have an outer diameter substantially equal to the outer diameter of the aerosol-generating article. The mouthpiece element may have an outer diameter of between 5 and 12 mm, 5 and 10 mm or 5 and 8 mm, 6 and 12 mm, 6 and 10 mm or 6 and 8 mm. The mouthpiece element may have an outer diameter of about 7.2 mm.

The mouthpiece element may have a length of at least 5, 8 or 10 mm. Alternatively or additionally, the mouthpiece element may have a length of less than 25, 20 or 15 mm. The mouthpiece element may have a length of about 12 mm.

Advantageously, the longer mouthpiece element may be more resilient to deformation or better adapted to recover its original shape after deformation, and may provide an improved grip for the consumer to insert the aerosol-generating article into the heating device. In addition, longer mouthpiece elements may provide higher levels of filtration and removal of unwanted aerosol components so that higher quality aerosols may be delivered. In addition, the use of longer mouthpiece elements enables more complex mouthpieces to be provided, as there is more space for incorporating mouthpiece components such as capsules, threads and limiters.

The aerosol-generating article may have a total length of between 38 and 70 mm, 40 and 70 mm, 42 and 70 mm, 38 and 60 mm, 40 and 60 mm or 42 and 60 mm, 38 and 50 mm, 40 and 50 mm or 42 and 50 mm. The aerosol-generating article may have an overall length of about 45 millimeters.

The aerosol-generating article may have an outer diameter of at least about 5, 6 or 7 millimeters. The aerosol-generating article may have an outer diameter of less than about 12, 10 or 8 millimeters. The aerosol-generating article may have an outer diameter of about 7.25 mm.

According to the present disclosure there is provided an aerosol-generating system comprising an aerosol-generating article and an aerosol-generating device as described above.

The aerosol-generating device may be an electric aerosol-generating device. The aerosol-generating device is engageable with and disengageable from the aerosol-generating article. For example, the aerosol-generating device may be configured to receive at least a portion of the aerosol-generating article.

The aerosol-generating device may be configured to heat the aerosol-generating article. The aerosol-generating device may be configured to resistively heat the aerosol-generating article. The device may comprise a heating element. The heating element may be configured to contact (e.g. penetrate) the aerosol-forming substrate in use. The heating element may be configured for resistive heating. The heating element may comprise a resistive track. In use, an electrical current may be passed through the rail to resistively heat the rail. The heating element may be in the form of a needle, a strip or a blade.

The aerosol-generating device may be configured to inductively heat the aerosol-generating article. The device may comprise an inductor, such as an inductor coil. The device may be configured to generate a fluctuating electromagnetic field. In use, this fluctuating electromagnetic field may induce eddy currents in the susceptor material, which is for example that of a thermally conductive material, or that of a heating element of the device, or both. Where the device comprises an inductively heatable heating element, this heating element may be configured to contact (e.g. penetrate) the aerosol-forming substrate in use. The heating element may be in the form of a needle, a strip or a blade. The eddy currents may heat the susceptor material, thereby heating the aerosol-forming substrate in use.

In a fourth aspect of the present disclosure, a method of forming an aerosol-forming substrate is provided.

The method may include combining a layer of aerosol-forming material with a layer of carbon-based thermally conductive material to form a co-laminate sheet.

The aerosol-forming substrate produced using this method may have the features described in relation to the first aspect.

The layer of aerosol-forming material may be a continuous sheet of aerosol-forming material. The layer of carbon-based thermally conductive material may be a continuous sheet of carbon-based thermally conductive material. In such cases, the method may include forming a continuous co-laminate sheet.

The method may further comprise gathering the co-laminated sheet transversely with respect to its longitudinal axis. The method may further include defining the gathered co-laminated sheet with a wrapper to form a strip.

When the method includes forming a continuous co-laminated sheet, the gathered sheet defined by the wrapper may form a continuous strip. In such cases, the method may additionally include cutting the continuous strip into a plurality of discrete strips.

Such a rod may be used as an aerosol-forming substrate for a heated aerosol-generating article. Preferably, the aerosol-generating article is a smoking article that generates an aerosol that can be inhaled directly into the user's lungs through the user's mouth. More preferably, the aerosol-generating article is a smoking article that generates a nicotine-containing aerosol that can be inhaled directly into the user's lungs through the user's mouth.

The step of combining the layers may comprise bringing the carbon-based thermally conductive material layer and the aerosol-forming material layer into contact with each other, preferably in intimate contact. The method may further comprise crimping the carbon-based material layer and the aerosol-forming material layer when they are in contact with each other. This may include feeding a layer of carbon-based material and a layer of aerosol-forming material through a crimping roller. The crimping rollers may engage the layers and crimp the layers together to form a continuous crimped co-laminate sheet. The crimped co-laminate sheet may have a plurality of spaced apart ridges or corrugations that are substantially parallel to the longitudinal axis of the sheet.

As used herein, the term "curl" is intended to be synonymous with the term "crepe" and means that the sheet has a plurality of substantially parallel ridges or corrugations. Preferably, the curled sheet of homogenised tobacco material has a plurality of ridges or corrugations substantially parallel to the cylindrical axis of the rod. This advantageously facilitates the aggregation of the curled sheets of homogenised tobacco material to form a rod. However, it will be appreciated that the crimped sheet of homogenized tobacco material used in the present invention may alternatively or additionally have a plurality of substantially parallel ridges or corrugations disposed at acute or obtuse angles to the cylindrical axis of the rod.

The step of combining the layers may comprise overlaying a sheet of carbon-based thermally conductive material over a sheet of aerosol-forming material.

Alternatively, the step of combining the sheets may comprise overlaying a sheet of aerosol-forming material on top of a sheet of carbon-based thermally conductive material.

In either case, the continuous process may be advantageously achieved by feeding one of a sheet of carbon-based thermally conductive material or a sheet of aerosol-forming material from the first reel onto the conveyor. Another sheet of carbon-based thermally conductive material or aerosol-forming material may be fed from the second reel onto the sheet from the first reel on a conveyor.

Optionally, the method further comprises the step of forming a layer of aerosol-forming material. The step of forming the aerosol-forming material layer may comprise a step of a papermaking process or preferably a casting process.

The step of forming the aerosol-forming material layer may comprise casting a slurry comprising an organic material. The organic material is preferably homogenized tobacco material.

The step of forming the sheet additionally includes drying the slurry to form an aerosol-forming material.

One or more steps of forming a layer of aerosol-forming material may be performed prior to the step of combining the layers, which may include overlaying a sheet of carbon-based thermally conductive material over the sheet of aerosol-forming material.

Alternatively, one or more steps of forming the layer of aerosol-forming material may be performed simultaneously with the step of combining the layers, which may include overlaying a sheet of carbon-based thermally conductive material over the sheet of aerosol-forming material. In particular, a sheet of aerosol-forming material may be formed over a sheet of carbon-based thermally conductive material. Preferably, the slurry of aerosol-forming material may preferably be cast directly onto the carbon-based thermally conductive material. The slurry may be dried while on top of the carbon-based thermally conductive material. In this way, the co-laminate sheet may be formed at the same time as the aerosol-forming material layer is provided. This is particularly advantageous in a continuous process to improve the speed and ease of manufacture of the co-laminate sheet.

In addition, the process of casting aerosol-forming materials typically requires casting the slurry onto a support structure. However, casting the aerosol-forming material onto the carbon-based thermally conductive material may advantageously eliminate the need for additional support structures.

Preferably, the slurry comprises an aerosol former, reinforcing fibers and a binder. These features are described in the first aspect as features of an aerosol-forming material.

Optionally, forming the slurry includes adding fibers.

Optionally, the method, e.g., the step of forming the slurry, includes first mixing the slurry. Optionally, the first mixing occurs at a first pressure of no more than 500, 400, 300, 250 or 200 mbar. Alternatively, the first mixing occurs for between 1 and 10 minutes, 2 and 8 minutes, or 3 and 6 minutes, for example about 4 minutes.

Optionally, the method, e.g., the step of forming the slurry, includes a second mixing after the first mixing. Optionally, the second mixing occurs at a second pressure that is less than the first pressure. Optionally, the second pressure does not exceed 500, 400, 300, 200, 150 or 100mbar. Alternatively, the second mixing occurs between 5 and 120 seconds, between 5 and 80 seconds, between 5 and 40 seconds, or between 10 and 30 seconds, for example about 20 seconds.

Casting the slurry may include casting the slurry onto a flat support, such as a steel flat support. Alternatively, as described above, the slurry may be cast directly onto a sheet or layer of carbon-based thermally conductive material.

Optionally, after casting the slurry and before drying the slurry, the method may include setting the thickness of the slurry, for example, to be between 100 and 1200 microns, 200 and 1000 microns, 300 and 900 microns, 500 and 700 microns, for example, about 600 microns.

Optionally, drying the slurry includes providing a gas flow, such as air, over or through the slurry. Optionally, the air stream is heated. Optionally, the gas stream is heated to a temperature between 100 and 160 degrees celsius or between 120 and 140 degrees celsius. Alternatively, the gas flow is provided for between 1 and 10 minutes or between 2 and 5 minutes. Alternatively, the drying the slurry comprises drying the slurry until the slurry has a moisture content of between 1 and 20 wt%, 2 and 15 wt%, 2 and 10 wt%, or 3 and 7 wt%.

Optionally, drying the slurry forms a precursor for forming a sheet of aerosol-forming material.

Optionally, the method comprises cutting the sheet of aerosol-forming material to form discrete elements of aerosol-forming material. In a continuous process, the step of cutting the sheet of aerosol-forming material may be the same as the step of severing the continuous strip to form discrete strips.

Alternatively or additionally, the method of the fourth aspect may include forming a layer of carbon-based thermally conductive material. This may include preparing, forming or manufacturing the reconstituted carbon-based material.

The step of manufacturing the reconstituted carbon-based material may comprise forming a slurry comprising thermally conductive particles. The step of manufacturing the reconstituted carbon-based material may additionally include casting and drying the slurry to form the reconstituted carbon-based material.

Preferably, the slurry may comprise fibers. Preferably, the slurry may include a binder. The presence of one or both of the fibers and binder in the slurry can increase the tensile strength of the cast and dried slurry.

Alternatively, the slurry may comprise an aerosol former.

Optionally, the slurry comprises water. Optionally, the slurry comprises between 20 and 90 wt%, 30 and 90 wt%, 40 and 85 wt%, 50 and 80 wt%, 60 and 80 wt%, or 60 and 75 wt% water.

Optionally, forming the slurry includes forming a first mixture. The first mixture may include fibers. The first mixture may include water. The first mixture may include an aerosol former.

Forming the slurry may include forming a second mixture. The second mixture may include thermally conductive particles. The second mixture may include a binder. Forming the slurry may include adding the second mixture to the first mixture to form a combined mixture.

Optionally, the method, e.g., the step of forming a slurry, includes a first mixing of the combined mixture. Optionally, the first mixing occurs at a first pressure of no more than 500, 400, 300, 250 or 200 mbar. Alternatively, the first mixing occurs for between 1 and 10 minutes, 2 and 8 minutes, or 3 and 6 minutes, for example about 4 minutes.

Optionally, casting the slurry includes casting the slurry onto a flat support, such as a steel flat support.

Optionally, after casting the slurry and before drying the slurry, the method includes setting the thickness of the slurry, for example, to be between 100 and 1200 microns, 200 and 1000 microns, 300 and 900 microns, 500 and 700 microns, for example, about 600 microns.

In a fifth aspect of the present disclosure, a method of forming a rod comprising an aerosol-forming substrate is provided. The method comprises the following steps:

providing a co-laminate sheet comprising a layer of aerosol-forming material and a layer of carbon-based thermally conductive material;

gathering the co-laminated sheet transversely with respect to its longitudinal axis; and

the gathered co-laminated sheet is defined with a wrapper to form a continuous strip.

The method of the fifth aspect may further comprise any of the steps of the method of the fourth aspect.

In a sixth aspect, there is provided a method of forming an aerosol-generating article comprising the method steps of the fifth aspect.

The method may comprise assembling the aerosol-generating article from a plurality of components, the plurality of components comprising an aerosol-forming substrate.

Such articles may be in the form of, for example, a strip comprising a plurality of components, including an aerosol-forming substrate, assembled within a wrapper or shell. The aerosol-generating article may have a length of between 30mm and 120mm, for example between 40mm and 80mm, for example about 45 mm. The aerosol-generating article may have a diameter of between 3.5mm and 10mm, for example between 4mm and 8.5mm, for example between 4.5mm and 7.5 mm.

Optionally, the aerosol-generating article comprises a front rod. Optionally, the aerosol-generating article comprises a first hollow tube, for example a first hollow cellulose acetate tube. Optionally, the aerosol-generating article comprises a second hollow tube, for example a second hollow cellulose acetate tube. Optionally, the second hollow tube comprises one or more ventilation holes. Optionally, the aerosol-generating article comprises an oral filter segment filter. Optionally, the aerosol-generating article comprises a wrapper, for example a paper wrapper.

Optionally, the front bar is disposed at the most upstream end of the article. Optionally, the aerosol-forming substrate is arranged downstream of the front rod. Optionally, the first hollow tube is arranged downstream of the aerosol-forming substrate. Optionally, the second hollow tube is arranged downstream of the first hollow tube. Optionally, the mouth filter segment filter is disposed downstream of one or both of the first hollow tube and the second hollow tube. Optionally, the mouth filter segment filter is disposed at the most downstream end of the article. Alternatively, the downstream-most end of the article, which may be referred to as the mouth end of the article, may be configured to be inserted into the mouth of the user. The user may be able to inhale, for example, directly on the mouth end of the article.

Optionally, the front rod, the aerosol-forming substrate, one or both of the first and second hollow tubes, and the mouth filter segment filter are defined by a wrapper, such as a paper wrapper.

Alternatively, the front bar has a length of between 2 and 10mm, 3 and 8mm or 4 and 6mm, for example about 5 mm. Alternatively, the aerosol-forming substrate within the article has a length of between 5 and 20mm, 8 and 15mm or 10 and 15mm, for example about 12 mm. Alternatively, the first hollow tube has a length of between 2 and 20mm, 5 and 15mm or 5 and 10mm, for example about 8 mm. Alternatively, the second hollow tube has a length of between 2 and 20mm, 5 and 15mm or 5 and 10mm, for example about 8 mm. Alternatively, the mouth filter segment filter has a length of between 5 and 20mm, 8 and 15mm or 10 and 15mm, for example about 12 mm. The length of one or more of the front rod, aerosol-forming substrate, first hollow tube, second hollow tube, and mouth filter segment filter may extend in a longitudinal direction.

One or more of the front rod, aerosol-forming substrate, first hollow tube, second hollow tube, and mouth filter segment filter may be substantially cylindrical in shape, such as right cylindrical.

As will be appreciated by those having skill in the art having read the present disclosure, features described herein with respect to one aspect may be applicable to any other aspect.

As used herein, the term "aerosol-forming substrate" may refer to a substrate capable of releasing an aerosol or volatile compounds that may form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may comprise an aerosol-forming material. The aerosol-forming substrate may be adsorbed, coated, impregnated or otherwise loaded onto the carrier or support. The aerosol-forming substrate may suitably be an aerosol-generating article or a part of a smoking article.

As used herein, the term "expanded graphite" may refer to a graphite-based material or a material having a graphite-like structure. The expanded graphite may have carbon layers (e.g., similar to graphite) with spacing between the carbon layers being greater than the spacing present between the carbon layers in regular graphite. The expanded graphite may have carbon layers with elements or compounds intercalated in the spaces between the carbon layers.

As used herein, the term "density" may be used to refer to the true density, unless otherwise specified. The measurement of true density can be accomplished using a number of standard methods, which are generally based on archimedes' principle. When used to measure the true density of a powder, the most widely used method requires that the powder be placed in a container (colorimeter) of known volume and weighed. The colorimeter is then filled with a fluid of known density, in which the powder is insoluble. The volume of the powder is determined by the difference between the volume as shown by the colorimeter and the volume of liquid added (i.e. the volume of air displaced).

As used herein, the term "aerosol-generating article" may refer to an article capable of generating or releasing an aerosol, for example, when heated.

As used herein, the term "longitudinal" may refer to a direction extending between a downstream or proximal end and an upstream or distal end of a component, such as an aerosol-forming substrate or an aerosol-generating article.

As used herein, the term "transverse" may refer to a direction perpendicular to the longitudinal direction.

As used herein, the term "aerosol-generating device" may refer to a device that is used with an aerosol-generating article to enable the generation or release of an aerosol.

As used herein, the term "sheet" may refer to a generally planar layered element having a width and length that are substantially greater than, for example, at least 2, 3, 5, 10, 20, or 50 times its thickness.

As used herein, the term "aerosol former" may refer to any suitable known compound or mixture of compounds that facilitate aerosol formation in use. The aerosol may be a dense and stable aerosol. The aerosol may be substantially resistant to thermal degradation at the operating temperature of the aerosol-forming substrate or aerosol-generating article.

As used herein, the term "bar" may refer to a generally cylindrical (e.g., right cylindrical) element having a substantially circular, oval, or elliptical cross-section.

As used herein, the term "curl" may refer to a sheet or discrete element having one or more ridges or corrugations. The ridges or corrugations may be substantially parallel. When present in a component of the aerosol-generating article, the ridges or corrugations may extend in a longitudinal direction relative to the aerosol-generating article.

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

Ex1 an aerosol-forming substrate for use in a heated aerosol-generating article, the aerosol-forming substrate comprising a co-laminated sheet comprising a layer of aerosol-forming material and a layer of carbon-based thermally conductive material.

Ex2 the aerosol-forming substrate according to example EX1, wherein the carbon-based thermally conductive material layer is a material comprising carbon, e.g., a material comprising or consisting of one or more of graphite, expanded graphite, graphene, carbon nanotubes, charcoal, and diamond.

Ex3. the aerosol-forming substrate according to example EX1 or EX2, wherein the layer of carbon-based thermally conductive material comprises or consists of at least one of graphite and expanded graphite.

Ex4. the aerosol-forming substrate according to any of examples EX1 to EX3, wherein the width of the co-laminated sheet is greater than 10mm, preferably greater than 20, 30, 40, 50, 60, 70, 80, 90, 100 millimeters.

Ex5 the aerosol-forming substrate according to any of examples EX1 to EX4, wherein the width of the co-laminated sheet is less than 300, 250, 200, 150 millimeters.

The aerosol-forming substrate according to any one of examples EX1 to EX5, wherein the aerosol-forming material layer of the co-laminate sheet is in intimate contact with the thermally conductive material layer.

The aerosol-forming substrate according to any one of examples EX1 to EX6, wherein the carbon-based thermally conductive material layer has a length and width similar to or the same as a length and width of the aerosol-forming material layer.

Ex8. the aerosol-forming substrate of any of examples EX1 to EX7, wherein the carbon-based thermally conductive material layer is in contact with the aerosol-forming material layer over substantially the entire surface of the thermally conductive material layer.

Ex9. the aerosol-forming substrate according to any of examples EX1 to EX8, wherein the layers of the co-laminated sheet form a single sheet.

Ex10. the aerosol-forming substrate of any of examples EX1 to EX9, wherein the co-laminated sheet comprises one or more aerosol-forming material layers.

Ex11. the aerosol-forming substrate according to any of examples EX1 to EX10, wherein the co-laminated sheet comprises one or more layers of thermally conductive material.

Ex12 the aerosol-forming substrate according to example EX10 wherein the or each aerosol-forming material layer is sandwiched between layers of thermally conductive material.

Ex13 the aerosol-forming substrate according to example EX11 wherein the or each aerosol-forming material layer is sandwiched between aerosol-forming material layers.

The aerosol-forming substrate according to any one of examples EX1 to EX13, wherein the co-laminated sheet comprises one or more additional layers comprising a material other than the carbon-based thermally conductive material layer and the aerosol-forming material layer.

Ex15. the aerosol-forming substrate according to any one of examples EX1 to EX14, wherein the or each layer of thermally conductive material is in the form of a film or foil.

The aerosol-forming substrate according to any one of examples EX1 to EX15, wherein the or each layer of thermally conductive material is flexible.

The aerosol-forming substrate according to any one of examples EX1 to EX16, wherein the or each aerosol-forming material layer is flexible.

The aerosol-forming substrate according to any one of examples EX1 to EX17, wherein the co-laminated sheet is flexible.

The aerosol-forming substrate of any of examples EX1 to EX18, wherein the or each layer of thermally conductive material has a thickness of less than 10, 5, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, or 0.02 millimeters.

The aerosol-forming substrate of any of examples EX1 to EX19, wherein the or each layer of thermally conductive material has a thickness between 10 and 0.02 millimeters, or 5 and 0.02 millimeters, 3 and 0.02 millimeters, 2 and 0.02 millimeters, 1 and 0.02 millimeters, 0.9 and 0.02 millimeters, 0.8 and 0.02 millimeters, 0.7 and 0.02 millimeters, 0.6 and 0.02 millimeters, 0.5 and 0.02 millimeters, 0.4 and 0.02 millimeters, 0.3 and 0.02 millimeters, 0.2 and 0.02 millimeters, 0.1 and 0.02 millimeters, 0.09 and 0.02 millimeters, 0.08 and 0.02 millimeters, 0.07 and 0.02 millimeters, 0.06 and 0.02 millimeters, 0.05 and 0.02 millimeters, and 0.04 and 0.02 millimeters.

Ex21 the aerosol-forming substrate of any of examples EX1 to EX20, wherein the carbon-based thermally conductive material layer comprises or consists of carbon fibers, graphite or graphene.

Ex22 the aerosol-forming substrate according to example EX21, wherein the layer of carbon-based thermally conductive material comprises or consists of expanded graphite.

Ex23 the aerosol-forming substrate according to example EX21 or EX22, wherein the layer of carbon-based thermally conductive material comprises both graphite and expanded graphite.

Ex24 the aerosol-forming substrate according to any one of examples EX21 to EX23, wherein the carbon-based thermally conductive material layer is composed of flexible graphite or flexible graphite and an expanded graphite foil or film.

The aerosol-forming substrate according to any one of examples EX1 to EX24, wherein the carbon-based thermally conductive material layer has a density less than or equal to the density of the aerosol-forming material.

The aerosol-forming substrate of any of examples EX1 to EX25, wherein the layer of thermally conductive material has a density that is at least 1%, 2%, 5%, 10%, 15%, 20%, 25% or 30% less than the density of the aerosol-forming material.

The aerosol-forming substrate according to any one of examples EX1 to EX26, wherein the aerosol-forming substrate has a density of less than 1050, 1000, 950, 900, 850, 800, 750, 700, or 650kg/m 3.

EX28 the aerosol-forming substrate of any of examples EX1 through EX27, wherein the aerosol-forming substrate has a molecular weight between 500 and 900kg/m ³ Between, for example, 600 and 800kg/m ³ Density of the two.

The aerosol-forming substrate of any of examples EX1 to EX28, wherein the carbon-based thermally conductive material layer has a thermal conductivity of less than 3, 2, 1.8, 1.5, 1.2, 1, 0.8, 0.5, 0.2, 0.1, 0.05, 0.02 grams per cubic centimeter (g/cm) ³ ) Is a density of (3).

The aerosol-forming substrate of any one of examples EX1 to EX29, wherein the carbon-based thermally conductive material layer has a thermal conductivity greater than 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 0.8, 1, 1.2, 1.5, or 1.8 grams/cubic centimeter (g/cm) ³ ) Is a density of (3).

The aerosol-forming substrate of any of examples EX1 to EX30, wherein the carbon-based thermally conductive material layer has a density between 0.01 and 3, 0.01 and 2, 0.01 and 1.8, 0.01 and 1.5, 0.01 and 1.2, 0.01 and 1, 0.01 and 0.8, 0.01 and 0.5, 0.02 and 3, 0.02 and 2, 0.02 and 1.8, 0.02 and 1.5, 0.02 and 1.2, 0.02 and 1, 0.02 and 0.8, 0.02 and 0.5, 0.01 and 3, 0.05 and 2, 0.05 and 1.8, 0.05 and 1.5, 0.05 and 1.2, 0.05 and 1, 0.05 and 0.8, 0.5g/cm3, 0.1 and 2, 0.1 and 1.8, 0.02 and 1, 0.2, 0.02 and 1.8, 0.5 and 1.5, 0.5, 0.0 and 2, 0.05 and 1.5 g/cm3, 0.0.0.5 and 2, 0.05 and 1, 0.5 and 2, 0.05 and 1.5 g/cm3, 0.0.0.0.05 and 2, 0.05 and 1.5, 0.5 and 2, 0.5 and 0.5g/cm3, 0.0.0.0.0.0.0.0.0.0.0.0.0.2 and 2, 0.5 and 2.

The aerosol-forming substrate of any of examples EX1 to EX31, wherein the layer of carbon-based thermally conductive material has a tensile strength greater than 1, 2, 3, 4, 5, 6, 7, 8, or 9 megapascals (Mpa).

Ex33 the aerosol-forming substrate according to any one of examples EX1 to EX32, wherein the carbon-based thermally conductive material layer comprises or consists of a reconstituted carbon-based material.

Ex34 the aerosol-forming substrate according to example EX33, wherein the layer of carbon-based thermally conductive material comprises or consists of a reconstituted sheet of graphite.

Ex35 the aerosol-forming substrate according to example EX33 or EX34, wherein the layer of carbon-based thermally conductive material comprises or consists of a reconstituted graphite film or foil.

Ex36 the aerosol-forming substrate according to any one of examples EX33 to EX35, wherein the reconstituted carbon-based material comprises thermally conductive particles.

Ex37 the aerosol-forming substrate according to example EX36, wherein each of the thermally conductive particles has a thermal conductivity of at least 1 watt/meter kelvin [ W/(mK) ] in at least one direction at 25 degrees celsius.

Ex38 the aerosol-forming substrate according to example EX36 or EX37, wherein some or all of the thermally conductive particles comprise carbon, e.g., at least 10, 30, 50, 70, 90, 95, 98, or 99 wt% carbon.

The aerosol-forming substrate according to any one of examples EX33 to EX38, wherein the reconstituted carbon-based material comprises an aerosol-former.

Ex40 the aerosol-forming substrate according to example EX39, wherein the reconstituted carbon-based material comprises between 7 and 60 wt% aerosol former on a dry weight basis.

Ex41 the aerosol-forming substrate according to any one of examples EX33 to EX40, wherein the reconstituted carbon-based material comprises fibers.

Ex42 the aerosol-forming substrate according to example EX41, wherein the reconstituted carbon-based material layer comprises between 2 and 20 wt% fibres on a dry weight basis. Alternatively, the fibers are cellulosic fibers.

Ex43 the aerosol-forming substrate according to any one of examples EX33 to EX42, wherein the reconstituted carbon-based material comprises a binder.

Ex44 the aerosol-forming substrate according to example EX43, wherein the reconstituted carbon-based material comprises between 2 and 10 wt% binder on a dry weight basis.

Ex45 the aerosol-forming substrate according to any one of examples EX33 to EX44, wherein the carbon-based thermally conductive material layer does not include tobacco.

EX46 the aerosol-forming substrate according to example EX45, wherein the carbon-based thermally conductive material layer may not include nicotine.

Ex47 the aerosol-forming substrate according to any one of examples EX33 to EX46, wherein the carbon-based thermally conductive material layer may be formed by a casting process.

Ex48 the aerosol-forming substrate according to any of examples EX1 to EX47, wherein the co-laminated sheet comprises or has the form of an aggregated sheet.

Ex49 the aerosol-forming substrate of any of examples EX1 to EX48, wherein the carbon-based thermally conductive material layer has a thermal conductivity greater than 2, 5, 10, 20, 50, 100, 200, 500, 1000, or 1500W/(mK).

The aerosol-forming substrate of any of examples EX1 to EX49, wherein the carbon-based thermally conductive material layer is located in or defines a plane, and wherein the thermal conductivity of the carbon-based thermally conductive material layer within the plane is greater than 2, 5, 10, 20, 50, 100, 200, 500, 1000, or 1500W/mK.

The aerosol-forming substrate according to any one of examples EX1 to EX50, wherein the layer of carbon-based thermally conductive material comprises greater than 10%, 30%, 50%, 70%, 80%, 90%, 95%, 98%, 99%, 99.5% or 99.9% carbon by weight.

The aerosol-forming substrate according to any one of examples EX1 to EX51, wherein the carbon-based thermally conductive material layer comprises less than or equal to 90, 80, 50, 20, 10, or 5 wt% of the aerosol-forming substrate.

The aerosol-forming substrate according to any one of examples EX1 to EX52, wherein the carbon-based thermally conductive material layer comprises greater than or equal to 0.1, 0.2, 0.5, 1, 2, 3, 5, 10, 20, 30, 40, or 50 wt% of the aerosol-forming substrate.

The aerosol-forming substrate according to any one of examples EX1 to EX53, wherein the carbon-based thermally conductive material layer comprises between 20 and 90 wt%, between 30 and 90 wt%, between 40 and 90 wt%, between 20 and 80 wt%, between 30 and 80 wt%, between 40 and 80 wt%, between 20 and 70 wt%, between 30 and 70 wt%, between 40 and 70 wt%, between 20 and 60 wt%, between 30 and 60 wt%, between 40 and 60 wt%, between 20 and 50 wt%, between 30 and 50 wt% of the aerosol-forming substrate.

Ex55 a rod for an aerosol-generating article comprising an aggregated sheet of aerosol-forming substrate according to any of examples EX1 to EX54, and a wrapper defining the aggregated sheet of aerosol-forming substrate.

Ex56. the rod according to example EX55, further comprises a susceptor element located within the rod of aerosol-forming substrate.

Ex57. the strip according to example EX56, wherein the susceptor element is an elongated susceptor element.

Ex58. a rod according to example EX56 or EX57, wherein the susceptor element extends longitudinally within the rod of aerosol-forming substrate.

Ex59. the strip of any one of examples EX56 to EX58, wherein the strip is substantially cylindrical in shape.

Ex60. a rod according to example EX59, wherein the susceptor element is positioned at a radial central position within the rod of aerosol-forming substrate and extends along a central longitudinal axis of the rod of aerosol-forming substrate.

Ex61. the strip according to any one of examples EX56 to EX60, wherein the susceptor element is in the form of a needle, a strip or a blade.

Ex62. the strip according to any one of examples EX56 to EX61, wherein the susceptor element has a length between 5 and 15 mm, 6 and 12 mm or 8 and 10 mm.

Ex63 the strip of example EX62, wherein the layer of carbon-based thermally conductive material comprises susceptor material.

Ex64 the strip according to example EX63, wherein no susceptor element is present in the aerosol-forming substrate or in the strip of aerosol-forming substrate other than the layer of thermally conductive material.

Ex65 an aerosol-generating article for use with an electric aerosol-generating device, the article comprising an aerosol-forming substrate according to any of examples EX1 to EX64.

EX66 an aerosol-generating article according to example EX65 comprises a plurality of elements assembled within a wrapper or shell in the form of a strip.

Ex67 the aerosol-generating article of example EX66, wherein the plurality of elements comprises an upstream element, the aerosol-forming substrate, a support element, an aerosol-cooling element, and a mouthpiece element.

An aerosol-generating system comprising an aerosol-generating article according to any of examples EX65 to EX67 and an electro-dynamic aerosol-generating device, wherein the aerosol-generating device is engageable with and disengageable from the aerosol-generating article.

Ex69 the aerosol-generating system of example EX68, wherein the aerosol-generating device is configured to resistively heat the aerosol-generating article.

Ex70. the aerosol-generating system of example EX69, wherein the device comprises a resistance-heatable heating element.

Ex71. the aerosol-generating system of example EX70, wherein the heating element comprises a resistive track.

Ex72 the aerosol-generating system of example EX71, wherein the aerosol-generating device is configured to inductively heat the aerosol-generating article.

EX73 the aerosol-generating system of example EX72, wherein the device comprises an inductor, such as an inductor coil.

Ex74 the aerosol-generating system of example EX73, wherein the apparatus is configured to generate a fluctuating electromagnetic field.

Ex75 a method of forming an aerosol-forming substrate comprising combining a layer of aerosol-forming material with a layer of carbon-based thermally conductive material to form a co-laminate sheet.

EX76 the method of example EX75, wherein the layer of aerosol-forming material is a continuous sheet of aerosol-forming material.

Ex77 the method of example EX75 or EX76 wherein the layer of carbon-based thermally conductive material is a continuous sheet of carbon-based thermally conductive material.

The method of any one of examples EX75 to EX77, wherein the method comprises forming a continuous co-laminate sheet.

The method of any one of examples EX75 to EX78, further comprising gathering the co-laminated sheet transversely relative to its longitudinal axis.

The method of any one of examples EX75 to EX79, wherein the method further comprises defining the gathered co-laminated sheet with a wrapper to form a strip.

Ex81. the method of example EX80, wherein the method comprises forming a continuous co-laminate sheet such that the gathered sheet defined with the wrapper forms a continuous strip.

Ex82 the method of example EX81, further comprising cutting the continuous strip into a plurality of discrete strips.

Ex83 the method according to any of examples EX75 to EX82, wherein the step of combining the layers comprises contacting, preferably intimately contacting, the carbon-based material layer and the aerosol-forming material layer with each other.

Ex84 the method of example EX83, further comprising crimping the carbon-based material layer and the aerosol-forming material layer when they are in contact with each other.

Ex85 the method of example EX84, wherein the crimping step comprises feeding the carbon-based material layer and the aerosol-forming material layer through a crimping roller to form a continuous crimped co-laminate sheet.

Ex86. the method of example EX84, wherein the crimped co-laminate sheet has a plurality of spaced apart ridges or corrugations that are substantially parallel to the longitudinal axis of the sheet.

Ex87 the method of any of examples EX75 to EX86, wherein the step of combining the sheets comprises overlaying a sheet of aerosol-forming material over a sheet of carbon-based thermally conductive material.

Ex88. the method of any one of examples EX75 to EX87, wherein the step of combining the layers comprises overlaying a sheet of the carbon-based thermally conductive material over a sheet of the aerosol-forming material.

Ex89 the method of any of examples EX75 to EX88, further comprising the step of forming the aerosol-forming material layer.

Ex90. the method according to example EX89, wherein the step of forming the aerosol-forming material layer comprises a step of a papermaking process or preferably a casting process.

Ex91 the method of example EX90 wherein the step of forming the aerosol-forming material layer comprises casting a slurry comprising an organic material.

Ex92. the method of example EX91, wherein the step of forming the sheet further comprises drying the slurry to form an aerosol-forming material.

The method of any one of examples EX91 to EX93, wherein the step of combining the sheets comprises overlaying the sheet of aerosol-forming material on top of the sheet of carbon-based thermally conductive material; and wherein one or more steps of forming the layer of aerosol-forming material are performed prior to the step of combining the layers.

Ex94 the method according to any one of examples EX91 to EX93, wherein one or more steps of forming the aerosol-forming material layer may be performed simultaneously with the step of combining the layers.

Ex95. the method of example EX94, wherein the sheet of aerosol-forming material is formed over the sheet of carbon-based thermally conductive material.

The method according to example EX95, wherein the step of forming the sheet of aerosol-forming material comprises casting a slurry of aerosol-forming material onto the carbon-based thermally conductive material layer, preferably directly onto the carbon-based thermally conductive material layer.

Ex97 the method of example EX96, further comprising the step of drying the slurry over the carbon-based thermally conductive material layer.

The method of any one of examples EX75 to EX97, further comprising forming the carbon-based thermally conductive material layer.

Ex99. the method of example EX98, wherein the step of forming the carbon-based thermally conductive material layer comprises preparing, forming, or manufacturing a reconstituted carbon-based material.

Ex100. The method of example EX99, wherein the step of fabricating the reconstituted carbon-based material comprises forming a slurry comprising thermally conductive particles.

Ex101 the method of example EX100 wherein the step of making the reconstituted carbon based material further comprises casting and drying the slurry to form the reconstituted carbon based material.

EX102 the method according to example EX99 or EX100, wherein the slurry comprises fibers.

The method of any one of examples EX99 to EX102, wherein the slurry comprises a binder.

The method of any one of examples EX99 to EX103, further wherein forming the slurry comprises forming a first mixture.

EX105 the method of example EX104, wherein the first mixture comprises fibers.

EX106 the method of example EX104 or EX105, wherein forming the slurry comprises forming a second mixture.

Ex107 the method of example EX106, wherein the second mixture comprises the thermally conductive particles.

Ex108 a method of forming a rod comprising an aerosol-forming substrate, the method comprising the steps of:

Ex109. a method according to example EX108, the method comprising any of the steps of the method defined in any of examples EX75 to EX108.

EX110A method of forming an aerosol-generating article, the method comprising the method steps of example EX108 or EX109.

Drawings

Specific embodiments will be further described, by way of example only, with reference to the accompanying drawings, in which:

fig. 1 shows a schematic cross-sectional view of a first embodiment of an aerosol-generating article;

FIG. 2 shows a schematic cross-sectional view of a first apparatus for forming a strip according to a specific embodiment;

FIG. 3 shows a schematic cross-sectional view of a first apparatus for forming a strip according to a specific embodiment;

fig. 4 shows a schematic cross-sectional view of a first embodiment of an aerosol-generating system;

Fig. 5 shows a schematic cross-sectional view of a second embodiment of an aerosol-generating system; and

fig. 6 shows a schematic cross-sectional view of a second embodiment of an aerosol-generating article.

Detailed Description

Fig. 1 shows a schematic cross-sectional view of a first embodiment of an aerosol-generating article 10. The aerosol-generating article 10 comprises a strip 12 of aerosol-forming substrate and a downstream section 14 at a position downstream of the strip 12 of aerosol-forming substrate. Furthermore, the aerosol-generating article 10 comprises an upstream section 16 at a position upstream of the strip 12 of aerosol-forming substrate. Thus, the aerosol-generating article 10 extends from an upstream or distal end 18 to a downstream or proximal or mouth end 20.

The aerosol-generating article has an overall length of about 45 mm.

The downstream section 14 includes a support element 22 immediately downstream of the rod 12 of aerosol-forming substrate, the support element 22 being longitudinally aligned with the rod 12. In the embodiment of fig. 1, the upstream end of the support element 22 abuts the downstream end of the strip 12 of aerosol-generating substrate. In addition, the downstream section 14 includes an aerosol-cooling element 24 immediately downstream of the support element 22, the aerosol-cooling element 24 being longitudinally aligned with the strip 12 and the support element 22. In the embodiment of fig. 1, the upstream end of the aerosol-cooling element 24 abuts the downstream end of the support element 22.

As will be apparent from the following description, the support element 22 and the aerosol-cooling element 24 together define an intermediate hollow section 50 of the aerosol-generating article 10. Overall, the intermediate hollow section 50 does not substantially contribute to the overall RTD of the aerosol-generating article. The RTD of the intermediate hollow section 26 is substantially 0 mm H overall ₂ O。

The support element 22 comprises a first hollow tubular section 26. The first hollow tube section 26 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular section 26 defines an inner lumen 28 extending from an upstream end 30 of the first hollow tubular section up to a downstream end 32 of the first hollow tubular section 20. The lumen 28 is substantially empty and thus a substantially unrestricted airflow is achieved along the lumen 28. The first hollow tubular section 26 and thus the support element 22 do not substantially contribute to the overall RTD of the aerosol-generating article 10. In more detail, the RTD of the first hollow tubular section 26 (which is essentially the RTD of the support element 22) is essentially 0 millimeters H ₂ O。

The first hollow tubular section 26 has a length of about 8 millimeters, an outer diameter of about 7.25 millimeters and an inner diameter (D) of about 1.9 millimeters _FTS ). Thus, the thickness of the peripheral wall of the first hollow tubular section 26 is about 2.67 millimeters.

The aerosol-cooling element 24 comprises a second hollow tubular section 34. The second hollow tubular section 34 is provided in the form of a hollow cylindrical tube made of cellulose acetate. A second hollow tubular section34 define an inner lumen 36 extending from an upstream end 38 of the second hollow tubular section up to a downstream end 40 of the second hollow tubular section 34. The interior cavity 36 is substantially empty and thus a substantially unrestricted airflow is achieved along the interior cavity 36. The second hollow tubular section 28, and thus the aerosol-cooling element 24, does not substantially contribute to the overall RTD of the aerosol-generating article 10. In more detail, the RTD of the second hollow tubular section 34 (which is essentially the RTD of the aerosol-cooling element 24) is essentially 0 millimeters H ₂ O。

The second hollow tubular section 34 has a length of about 8 millimeters, an outer diameter of about 7.25 millimeters and an inner diameter (D) of about 3.25 millimeters _STS ). Thus, the thickness of the peripheral wall of the second hollow tubular section 34 is about 2 millimeters. Thus, the inner diameter (D _FTS ) And an inner diameter (D) of the second hollow tubular section 34 _STS ) The ratio between them is about 0.75.

The aerosol-generating article 10 comprises a ventilation zone 60 provided at a position along the second hollow tubular section 34. In more detail, the ventilation zone is provided at about 2 mm from the upstream end of the second hollow tubular section 34. In this embodiment, the ventilation zone 60 comprises a row of circumferential perforations through the paper wrapper 70, and the ventilation level of the aerosol-generating article 10 is about 25%.

In the embodiment of fig. 1, the downstream section 14 further comprises a mouthpiece element 42 at a location downstream of the intermediate hollow section 50. In more detail, the mouthpiece element 42 is positioned immediately downstream of the aerosol-cooling element 24. As shown in the diagram of fig. 1, the upstream end of the mouthpiece element 42 abuts the downstream end 40 of the aerosol-cooling element 24.

The mouthpiece element 42 is provided in the form of a cylindrical filter segment of low density cellulose acetate.

The mouthpiece element 42 has a length of about 12 mm and an outer diameter of about 7.25 mm. The RTD of the mouthpiece element 42 is about 12 mm H ₂ O. The ratio of the length of the mouthpiece element 42 to the length of the intermediate hollow section 50 is about 0.6.

The strips 12 of aerosol-forming substrate have an outer diameter of about 7.25 mm and a length of about 12 mm.

Upstream section 16 comprising a gas-soluble layerThe glue forms an upstream element 46 immediately upstream of the strip 12 of matrix, the upstream element 46 being longitudinally aligned with the strip 12. In the embodiment of fig. 1, the downstream end of the upstream element 46 abuts the upstream end of the rod 12 of aerosol-forming substrate. The upstream element 46 is provided in the form of a cylindrical filter segment of cellulose acetate. The upstream element 46 has a length of about 5 mm. The RTD of upstream element 46 is about 30 millimeters H ₂ O。

The upstream element 46, the strip 12 of aerosol-forming substrate, the support element 22, the aerosol-cooling element 24 and the mouthpiece element 42 are defined by a paper wrapper 70.

The strip 12 of aerosol-forming substrate comprises an aggregated co-laminated sheet comprising a layer 13 of aerosol-forming material and a layer 15 of carbon-based thermally conductive material. The aerosol-forming material layer 13 is in intimate contact with a layer of carbon-based thermally conductive material, one layer being stacked on top of the other. As will be described below, the sheets are gathered so as to form a plurality of substantially parallel ridges or corrugations. Thus, the cross-section of the sheet shown in fig. 1 appears to have a plurality of aerosol-forming material layers 13 sandwiched between carbon-based thermally conductive material layers 15 produced by the corrugated co-laminated structure of the strips 12 of aerosol-forming substrate.

The aerosol-forming material 13 comprises a reconstituted sheet comprising tobacco material and glycerin.

The carbon-based thermally conductive material layer 15 is a foil made of graphite, expanded graphite, or both graphite and expanded graphite.

The paperboard tube 34 has a length of 16mm and provides a free space within the article 10 in which volatile components generated by heating the aerosol-forming substrate can cool and form an aerosol.

The mouthpiece element 42 is provided in the form of a cylindrical filter segment of low density cellulose acetate. The mouthpiece element 42 has a length of about 12 millimeters and an outer diameter of about 7.2 mm. The RTD of the mouthpiece element 42 is about 12 mm H2O.

It should be clear that the configuration of the aerosol-generating article 10 of fig. 1 is intended to be used as an example only. The thermally enhanced aerosol-forming substrate may be used, for example, in longer (e.g., 80mm long) and thinner (e.g., 4.5mm diameter) aerosol-generating articles.

Fig. 2 shows an apparatus for forming a rod 12 of aerosol-forming substrate. The apparatus generally includes: a supply for providing a continuous co-laminated sheet of homogenized tobacco and aluminium foil; crimping means for crimping the continuous co-laminate sheet; a strip forming device for gathering the continuous rolled co-laminate sheet and defining a gathered material with the wrapper to form a continuous strip; and a cutting device for cutting the continuous strip into a plurality of discrete strips. The apparatus further comprises a conveying means for conveying the continuous co-laminated sheet of material downstream through the apparatus from the supply means to the strip forming means via the crimping means.

As shown in fig. 2, the supply means for providing a continuous co-laminate sheet comprises a continuous co-laminate sheet comprising a layer of aerosol-forming material and a layer of thermally conductive material, the continuous co-laminate sheet being mounted on a reel 4. The crimping device comprises a pair of rotatable crimping rollers 6. In use, the continuous co-laminate sheet 2 is drawn from the first reel 4 and conveyed downstream by the conveying means via a series of guide rollers and tensioning rollers to a pair of crimping rollers 6. As the continuous co-laminate sheet 2 is fed between a pair of crimping rollers 6, the crimping rollers engage and crimp the co-laminate sheet 2 to form a continuous crimped co-laminate sheet 8 having a plurality of spaced apart ridges or corrugations substantially parallel to the longitudinal axis of the sheet passing through the apparatus.

The continuous curled sheet 8 is conveyed downstream from the pair of curled rollers 6 toward the bar forming device and fed through a converging funnel or horn (horn) 31. The converging funnel 31 transversely gathers the continuous co-laminate sheet 8 with respect to its longitudinal axis. The sheet 8 of material assumes a substantially cylindrical configuration as it passes through the converging funnel 31.

Upon exiting the converging funnel 31, the gathered co-laminated sheet is packaged in a continuous sheet of packaging material 37. A continuous sheet of wrapping material is fed from a reel 35 and is wrapped around the gathered continuous curled sheet of homogenised tobacco material by an endless belt conveyor or fitting (garniture). As shown in fig. 1, the strip forming device comprises adhesive application means 17 which apply adhesive to one of the longitudinal edges of the continuous sheet of packaging material such that when the opposite longitudinal edges of the continuous sheet of packaging material are in contact they adhere to each other to form a continuous strip.

The strip forming apparatus further comprises drying means 19 downstream of the adhesive application means 17 which, in use, dries adhesive applied to the seam of the continuous strip as the continuous strip is transported downstream from the strip forming apparatus to the cutting means.

The cutting means comprise a rotary cutter 21 which cuts the continuous strip into discrete strips of unit strip length or multiple unit strip lengths.

Fig. 3 shows an alternative apparatus for forming a strip 12 of aerosol-forming substrate. The apparatus of fig. 3 is similar to that of fig. 2, and like features are numbered correspondingly. The difference between the apparatus of fig. 2 and 3 is that the apparatus of fig. 3 comprises separate rolls of continuous sheet of aerosol-forming material and continuous sheet of thermally conductive material instead of 35 a single roll of co-laminated sheet comprising aerosol-forming substrate.

In the apparatus of fig. 3, a continuous sheet of aerosol-forming material is mounted on the primary spool 23 and a continuous sheet of carbon-based thermally conductive material is mounted on the secondary spool 33. In use, a continuous sheet of aerosol-forming material is drawn from the main roll 23 and conveyed downstream through a conveyor mechanism to a pair of crimping rollers 6 via a series of guide and tensioning rollers. Similarly, a continuous sheet of carbon-based thermally conductive material is drawn from the secondary reel 33 and conveyed downstream by a conveying mechanism to a pair of crimping rollers 6. The continuous sheet of carbon-based thermally conductive material is brought into intimate contact with the aerosol-forming material prior to passing through the crimping rollers 6 such that the carbon-based thermally conductive material is overlaid with the aerosol-forming material. This forms a continuous co-laminated sheet comprising a layer of carbon-based thermally conductive material and a layer of aerosol-forming material passing through the crimping rollers 6. The continuous co-laminate sheet then proceeds through the apparatus of fig. 3 in the same manner as described with respect to fig. 2.

In other embodiments, a roll of aerosol-forming material may be exchanged with a roll of carbon-based thermally conductive material such that the aerosol-forming material is coated with the carbon-based thermally conductive material prior to passing through the crimping rollers.

In one embodiment, the aerosol-forming material described above is formed by a casting process comprising the steps of:

premixing the fine cut tobacco material, binder, guar gum with an aerosol former, glycerin to form a premix;

mixing the premix with water to form a slurry;

homogenizing the slurry using a high shear mixer;

casting the slurry onto a conveyor belt; and

the thickness of the slurry is controlled and the slurry is dried to form a large sheet of aerosol-forming material.

The process described above may be used to produce a continuous sheet of aerosol-forming material for the spool 23 of the apparatus of figure 3.

In another embodiment, the aerosol-forming material described above is formed by a casting process comprising the steps of:

mixing the premix with water to form a slurry;

homogenizing the slurry using a high shear mixer;

casting the slurry onto a continuous sheet of carbon-based thermally conductive material; and

The above process may be used to produce a continuous co-laminate sheet comprising a layer of aerosol-forming material. The process described above may be used to produce a continuous sheet of aerosol-forming material for the mandrel 4 of the apparatus of figure 2.

In one embodiment, the carbon-based thermally conductive material is a commercially available foil or film.

Suitable carbon-based thermally conductive materials are available from NeoGraf Solutions LLC (11709Madison Avenue,Lakewood,Ohio,United States 44107). In particular, the eGraf SpreaderShield (registered trademark) heat sink series is a suitable carbon-based heat conductive material. NeoGraf solutions provides a low density heat sink in the form of a film or foil and having an in-plane thermal conductivity between 300 and 1600W/(mK), a thickness as low as 17 microns, and a tensile strength greater than 7 mpa.

Another example of a suitable carbon-based thermally conductive material is the EYGS182307PGS graphite sheet series of Panasonic Industry available from RS Componentshttps://uk.rs-online.com/web/)。

In another embodiment, the carbon-based thermally conductive material is a reconstituted carbon-based material.

In one embodiment, the method includes forming a reconstituted carbon-based material. The slurry is formed using a laboratory disperser capable of mixing a viscous liquid, dispersing the powder through the liquid, and removing gas from the mixture (e.g., by applying a vacuum or other suitable low pressure). In this example, a laboratory disperser commercially available from PC Laborsystem was used.

To form a slurry, a first mixture was formed by adding about 7.11 grams of aerosol former, then about 157.5 grams of water, then about 1.57 grams of fibers to a laboratory disperser. These first ingredients are then mixed at 600-700rpm for 5 minutes at 25 degrees celsius to ensure a uniform mixture and to hydrate the fibers. The second mixture was then formed by manually mixing about 32.95 grams of thermally conductive particles and about 0.92 grams of binder. This mixing of the second mixture avoids the formation of lumps in the laboratory disperser. The second mixture is then added to the first mixture to form a combined mixture. The combined mixture was then mixed at 5000rpm for 4 minutes at 25 degrees celsius and a first reduced pressure of about 200 mbar. The reduced pressure can help ensure that the thermally conductive particles are uniformly dispersed in the mixture and that there is little entrapped air and lumps in the combined mixture. The combined mixture was then mixed at 5000rpm for 20 seconds at 25 degrees celsius and a second reduced pressure of about 100 mbar. This second reduced pressure may help to remove any remaining bubbles. This forms a slurry for casting.

The slurry is then cast and dried using suitable equipment. In this example, a commercially available Labcoater Mathis equipment was used. The apparatus includes stainless steel, a flat support, and a coma blade for adjusting the thickness of the slurry cast onto the flat support.

The slurry was cast onto a flat support, and the gap between the comb blade and the flat support was set to 0.6 mm. This ensures that the thickness of the slurry does not exceed 0.6 mm at any given point.

The slurry was then dried with hot air at 120 to 140 degrees celsius for 2 to 5 minutes. After this drying, a sheet of aerosol-forming substrate is formed. The sheet had a thickness of about 159 microns, a grammage of about 125.7 grams per square meter, and a density of about 0.79 kilograms per cubic meter.

Fig. 4 shows a schematic cross-sectional view of a first embodiment of an aerosol-generating system 100. The system 100 comprises an aerosol-generating device 102 and the aerosol-generating article 10 of fig. 1.

The aerosol-generating device 102 includes a battery 104, a controller 106, a heating blade 108 coupled to the battery, and a puff detection mechanism (not shown). The controller 106 is coupled to the battery 104, the heater blade 108, and the suction detection mechanism.

The aerosol-generating device 102 further comprises a housing 110 defining a substantially cylindrical cavity for receiving a portion of the article 10. The heating blades 108 are centrally located within the cavity and extend longitudinally from the bottom of the cavity.

In this embodiment, the heater blade 108 includes a substrate and a resistive track on the substrate. The battery 104 is coupled to the heating blade 108 to enable current to pass through the resistive track and heat the resistive track and the heating blade 108 to an operating temperature.

In use, a user inserts the article 10 into the cavity such that the heating blade 108 penetrates the upstream element 46 of the article 10 and the strip 12 of aerosol-forming substrate. Fig. 4 shows the article 10 inserted into a cavity of the device 102.

The user then draws on the downstream end of the article 10. This causes air to flow through the air inlet (not shown) of the device 102, then through the article 10, from the upstream end 18 to the downstream end 20, and into the user's mouth.

The user draws air over the article 10 through the air inlet of the device. The suction detection mechanism detects that the air flow rate through the air inlet has increased to greater than a non-zero threshold flow rate. The suction detection mechanism accordingly sends a signal to the controller 106. The controller 106 then controls the battery 104 to pass current through the resistive track and heat the heater blade 108. This heats the strip 12 of aerosol-forming substrate in contact with the heating blade 108.

The layer of thermally conductive material has a significantly higher thermal conductivity than the surrounding aerosol-forming material. Thus, the layer of thermally conductive material may conduct thermal energy throughout the aerosol-forming material block. This may allow a greater proportion of the aerosol-forming substrate to reach a sufficiently high temperature to release volatile compounds and thus allow for more efficient use of the aerosol-forming substrate.

Heating the aerosol-forming substrate causes the aerosol-forming substrate to release the volatile compound. These compounds are entrained by the air flowing from the upstream end 18 of the article 10 toward the downstream end 20 of the article 10. These compounds cool and condense to form an aerosol as they pass through the lumens 28, 36 of the support element 22 and the aerosol-cooling element 24. The aerosol then passes through the mouthpiece element 42, which may filter out unwanted particles entrained in the airflow, and into the mouth of the user.

When the user stops inhaling on the article 10, the airflow rate through the air inlet of the device is reduced to less than the non-zero threshold flow rate. This is detected by the suction detection mechanism. The suction detection mechanism accordingly sends a signal to the controller 106. The controller 106 then controls the battery 104 to reduce the current through the resistive track to zero.

After multiple puffs on the article 10, the user may choose to replace the article 10 with fresh article.

Fig. 5 shows a schematic cross-sectional view of a second embodiment of an aerosol-generating system 200. The system 200 comprises an aerosol-generating device 202 and the aerosol-generating article 11 of fig. 1.

The aerosol-generating device 202 comprises a battery 204, a controller 206, an inductor coil 208 and a puff detection mechanism (not shown). The controller 206 is coupled to the battery 204, the inductor coil 208, and the puff detection mechanism.

The aerosol-generating device 202 further comprises a housing 210 defining a substantially cylindrical cavity for receiving a portion of the article 11. The inductor coil 208 spirals around the cavity.

The battery 204 is coupled to the inductor coil 208 to enable an alternating current to pass through the inductor coil 208.

In use, a user inserts the article 11 into the cavity. Fig. 5 shows the article 11 inserted into the cavity of the device 202.

The user then draws on the downstream end of the article 11. This causes air to flow through the air inlet (not shown) of the device 202, then through the article 11, from the upstream end 18 to the downstream end 20, and into the user's mouth.

The user draws air over the article 11 through the air inlet of the device. The suction detection mechanism detects that the air flow rate through the air inlet has increased to greater than a non-zero threshold flow rate. The suction detection mechanism accordingly sends a signal to the controller 206. The controller 206 then controls the battery 204 to pass alternating current through the inductor coil 208. This causes the inductor coil 208 to generate a fluctuating electromagnetic field. A strip 13 of combined aerosol-forming substrate is located within this fluctuating electromagnetic field. The material of the thermally conductive material 15, graphite and expanded graphite is a susceptor material. Thus, the fluctuating electromagnetic field causes eddy currents in the thermally conductive material 15 (which is also electrically conductive). This heats the thermally conductive material 15 and thereby also heats the nearby aerosol-forming material.

Heating the aerosol-forming material causes the aerosol-forming material to release volatile compounds. These compounds are entrained by the air flowing from the upstream end 18 of the article 11 toward the downstream end 20 of the article 11. These compounds cool and condense to form an aerosol as they pass through the lumens 28, 36 of the support element and the aerosol-cooling element. The aerosol then passes through the mouthpiece element 42, which may filter out unwanted particles entrained in the airflow, and into the mouth of the user.

When the user stops inhaling on the article 11, the airflow rate through the air inlet of the device is reduced to less than the non-zero threshold flow rate. This is detected by the suction detection mechanism. The suction detection mechanism accordingly sends a signal to the controller 206. The controller 206 then controls the battery 204 to reduce the current through the resistive track to zero.

After a number of puffs on the article 11, the user may choose to replace the article 11 with fresh article.

Fig. 6 shows a schematic cross-sectional view of a second embodiment of an aerosol-generating article 510. This second embodiment is identical to the first embodiment of fig. 1, except that the strips 12 of aerosol-forming substrate have been replaced by alternative strips 512 of aerosol-forming substrate. In the embodiment of fig. 1 and 6, the same reference numerals have been used for the same components.

The strip 512 of aerosol-forming substrate of the second embodiment of fig. 6 is identical to the strip 12 of aerosol-forming substrate of the first embodiment of fig. 1, except that the strip 512 of aerosol-forming substrate of the second embodiment of fig. 6 additionally comprises an elongated susceptor element 580.

The susceptor element 580 is arranged substantially longitudinally within the strip 512 of aerosol-forming substrate so as to be substantially parallel to the longitudinal axis of the strip 512 of aerosol-forming substrate. As shown in the diagram of fig. 6, the susceptor element 580 is positioned at a radially central location within the strip and extends along the longitudinal axis of the strip 12.

The susceptor element 580 extends from an upstream end to a downstream end of the strip 512 of aerosol-forming substrate. Thus, the susceptor element 580 has substantially the same length as the strip 512 of aerosol-forming substrate.

In the embodiment of fig. 6, the susceptor element 580 is provided in the form of a strip of ferromagnetic steel and has a length of about 12 millimeters, a thickness of about 60 micrometers, and a width of about 4 millimeters.

The aerosol-generating article 510 of fig. 6 may be used with the aerosol-generating device 202 of fig. 4 in the same manner as the aerosol-generating article 11 of fig. 2. Notably, the inclusion of susceptor element 580 means that article 510 can be inductively heated, regardless of whether the thermally conductive material includes a suitable susceptor material for inductive heating.

For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing quantities, amounts, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may or may not be specifically recited herein. Thus, in this context, the number a is understood to be ±10% of a. In this context, the number a may be considered to include values within the general standard error of measurement of the property modified by the number a. In some cases, as used in the appended claims, the number a may deviate from the percentages recited above, provided that the amount of deviation a does not materially affect the basic and novel characteristics of the claimed invention. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may or may not be specifically recited herein.

Claims

1. An aerosol-forming substrate for use in a heated aerosol-generating article, the aerosol-forming substrate comprising a co-laminated sheet comprising a layer of aerosol-forming material and a layer of carbon-based thermally conductive material.

2. An aerosol-forming substrate according to claim 1, wherein the layer of carbon-based thermally conductive material is in the form of a film or foil.

3. The aerosol-forming substrate according to claim 1 or 2, wherein the layer of carbon-based thermally conductive material comprises or consists of carbon fibres, graphite or graphene.

4. An aerosol-forming substrate according to any preceding claim, wherein the layer of thermally conductive material comprises a material having a thermal conductivity of greater than 1W/mK.

5. An aerosol-forming substrate according to any preceding claim, wherein the co-laminated sheet comprises or is in the form of an aggregated sheet.

6. An aerosol-forming substrate according to any one of the preceding claims, wherein the layer of thermally conductive material comprises a reconstituted carbon-based material comprising thermally conductive particles.

7. An aerosol-forming substrate according to any preceding claim, wherein the layer of thermally conductive material has a tensile strength of greater than 1 megapascal (MPa).

8. A rod for an aerosol-generating article, the rod comprising an aerosol-forming substrate according to any of claims 1 to 7.

9. A heated aerosol-generating article comprising a rod according to claim 8.

10. An aerosol-generating system comprising an aerosol-generating article according to claim 9 and an electrically operated aerosol-generating device.

11. A method of forming an aerosol-forming substrate comprising:

the aerosol-forming material layer is combined with the carbon-based thermally conductive material layer to form a co-laminate sheet.

12. A method of forming an aerosol-forming substrate according to claim 11, wherein the method further comprises the step of forming a sheet of the aerosol-forming material.

13. A method of forming an aerosol-forming substrate according to claim 12, wherein the step of combining the sheets comprises casting the sheet of aerosol-forming material over the sheet of carbon-based thermally conductive material.

14. A method of forming a rod comprising an aerosol-forming substrate; the method comprises the following steps:

providing a co-laminate sheet comprising an aerosol-forming material and a carbon-based thermally conductive material;

gathering the co-laminated sheet transversely with respect to its longitudinal axis;

defining an aggregated co-laminated sheet with a wrapper to form a continuous strip; and

the continuous strip is cut into a plurality of discrete strips.

15. A method of forming an aerosol-generating article comprising assembling the aerosol-generating article from a plurality of components comprising an aerosol-forming substrate according to any of claims 1 to 7.