RU2730708C2 - Aerosol-generating article with insulated heat source - Google Patents

Abstract

FIELD: liquid atomisation or spraying devices.SUBSTANCE: invention relates to aerosol-generating articles and methods of making said articles. Aerosol-generating article (2) comprises aerosol-forming substrate (4), combustible heat source (3) and at least one layer of fiber-reinforced aerogel (5), surrounding at least part of length of combustible heat source (3). Aerosol-generating article (2) also comprises one or more airflow passages along which air can be drawn through article (2) for inhalation by a user, and one or more non-combustible substantially air-permeable partitions between combustible heat source (3) and aerosol-forming substrate (4).EFFECT: invention allows reducing the surface temperature near the heat source and can be easily and efficiently assembled.15 cl, 5 dwg

Description

The present invention relates to an aerosol generating article that contains an aerosol forming substrate and a combustible heat source, and to a method for making such an aerosol generating article.

The prior art provides a variety of aerosol generating products in which tobacco is heated rather than burned. One of the goals of such “heated” aerosol generating articles is to reduce the known harmful smoke constituents that result from the combustion and pyrolytic degradation of tobacco in combustible cigarettes. In an aerosol-generating heated article of one known type, an aerosol is generated by transferring heat from a combustible heat source to an aerosol-forming substrate that is adjacent to the combustible heat source. When the aerosol is generated, volatile compounds are released from the aerosol-forming substrate by heat transfer from a combustible heat source and are entrained in air drawn in through the aerosol-generating article. When the released compounds are cooled, they condense to form an aerosol that is inhaled by the user.

The combustion temperature of a combustible heat source for use in an aerosol-generating heated article should not be so high as to cause combustion or thermal degradation of the aerosol-forming substrate during use of the aerosol-generating heated article. However, the combustion temperature of the combustible heat source must be high enough to generate enough heat to release enough volatile compounds from the aerosol-forming substrate to create a suitable aerosol, especially during the first puffs.

The prior art to which the present invention relates to a number of combustible heat sources for use in heated products that generate aerosol. The combustion temperature of combustible heat sources for use in heated articles that generate aerosol is typically from about 600 ° C to about 800 ° C.

It is known to wrap an insulating element around the periphery of a combustible heat source of an aerosol-generating heated article in order to reduce the surface temperature of the aerosol-generating heated article. However, it has been found that such insulating elements can reduce the temperature of the combustible heat source during combustion of the combustible heat source, potentially reducing the efficiency of the heat source in heating the aerosol forming substrate to generate the aerosol. This effect is especially noticeable when the insulating element substantially increases the length of the combustible heat source. Such insulating elements can also prevent sustained combustion of the combustible heat source, thereby reducing the duration of combustion of the combustible heat source.

It would be desirable to provide an aerosol generating article that has a reduced surface temperature near the heat source, an acceptable appearance, and can be easily and efficiently assembled. It would also be desirable to provide an aerosol generating article that generates a suitable aerosol both during the first puffs and during the last puffs.

According to a first aspect of the present invention, an aerosol generating article is provided comprising an aerosol forming substrate, a combustible heat source, and at least one layer of fiber reinforced airgel surrounding at least a portion of the length of the combustible heat source. The aerosol generating article also includes one or more air flow passages along which air can be drawn in for inhalation by the user, and one or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol forming substrate. Said one or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol forming substrate isolate the combustible heat source from said one or more air flow passages such that, in use, air drawn in through the aerosol generating article along one or more air flow passages, not in direct contact with a combustible heat source.

In use, a combustible heat source may be ignited by an external heat source such as a lighter and may start to burn. A combustible heat source can heat the aerosol-forming substrate so that the volatile compounds of the aerosol-forming substrate are vaporized. When the user puffs on the aerosol generating article, air can be drawn into the aerosol generating article through the one or more air flow passages and mixed with the steam produced by the aerosol generating heating substrate to form the aerosol. The aerosol can be drawn from the aerosol generating article and delivered to the user for inhalation by the user.

Said at least one layer of fiber-reinforced airgel surrounding at least a portion of the length of the combustible heat source may insulate the combustible heat source. This can reduce the surface temperature of the aerosol generating article in the combustible heat source. Said at least one layer of fiber-reinforced airgel can also pass a sufficient amount of air through the layer so as not to substantially interfere with the combustion of the combustible heat source.

In the context of this document, the terms "airgel" and "unreinforced airgel" are used interchangeably to describe open cell foam. The airgel can be of the mesoporous type. The term "mesoporous" refers to a material having pores ranging in diameter from about 2 nanometers to about 50 nanometers. The airgel can contain a network of interconnected structures, and the network of interconnected structures can be nanostructures. The airgel can have a porosity of about 50 percent or more. The airgel can have a porosity of about 90 percent or more. An airgel can be created by extracting a liquid component from a conventional gel. A conventional gel will be understood to mean a semi-solid colloidal suspension of a solid suspension diluted in a liquid.

Aerogels generally have very low thermal conductivity. While not wishing to be bound by theory, conductive heat transfer in aerogels slows down due to their high porosity, while convective heat transfer in aerogels slows down due to their small pore diameter. The small pore diameter limits the movement of air through the airgel.

In the context of this document, the term "fiber-reinforced airgel" refers to a composite material containing an airgel matrix reinforced with a fibrous material. By fibrous material is meant a material containing fibers.

Although unreinforced aerogels can have an interconnected porous structure, the average pore width that unreinforced aerogels have is similar to the average free path of air molecules at room temperature. As a result, unreinforced aerogels have low air permeability. It is clear that this is due to the Knudsen effect.

The average pore width of fiber-reinforced aerogels is greater than the average free path of air molecules at room temperature. The longer pore length of breathable fiber-reinforced aerogels compared to non-breathable unreinforced aerogels reduces the effects of the Knudsen effect. As a result, it was found that fiber-reinforced aerogels have greater air permeability than unreinforced aerogels.

It has also been observed that fiber-reinforced aerogels have better mechanical properties than unreinforced aerogels. For example, fiber-reinforced aerogels can be more flexible and more amenable to mechanical processing than unreinforced aerogels.

Said at least one fiber-reinforced layer surrounds at least part of the length of the combustible heat source. The at least one layer of fiber-reinforced airgel according to the present invention can surround substantially the entire length of the combustible heat source. This can provide an advantage for the aerosol generating article in terms of the insulating properties of the fiber-reinforced airgel, lowering the surface temperature near the heat source of the aerosol-generating article on a combustible heat source, and also provide the advantage in terms of the air permeability of the fiber-reinforced airgel, allowing sufficient ambient air to reach a combustible heat source so that the combustible heat source ignites and burns substantially unhindered. It has also been observed that a combustible heat source substantially surrounded by said at least one layer of fiber-reinforced airgel can provide combustion of a combustible heat source at a higher temperature and for a longer time than a combustible heat source not surrounded by any layer of material. ...

The fiber-reinforced airgel of the present invention can also have processability, which facilitates the formation of a layer of fiber-reinforced airgel surrounding at least a portion of the length of the heat source. In the context of this document, the term "layer" is used to describe a body of material, generally corresponding to the shape of a combustible heat source. The at least one layer of fiber-reinforced airgel can be any suitable type of layer located around the circumference of the heat source. Suitable types of layers include, but are not limited to, wrappers and coatings. In the context of this document, the term "coating" is used to describe a layer of material that covers the heat source and is adhered to it.

The at least one layer of fiber-reinforced airgel may be in direct contact with a combustible heat source. The at least one layer of fiber-reinforced airgel may be located at a distance from the combustible heat source.

In the context of this document, the term "length" is used to describe the size of a component or part of an aerosol generating article in the longitudinal direction of the aerosol generating article. The at least one layer of fiber-reinforced airgel surrounds at least part of the length of the combustible heat source. For example, said at least one layer of fiber-reinforced airgel may surround approximately half the length of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround more than half the length of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround from about 60 percent to about 100 percent of the length of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround at least about 70 percent of the length of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround at least about 80 percent of the length of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround at least about 90 percent of the length of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround the entire length of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround substantially the length of the combustible heat source.

The at least one layer of fiber-reinforced airgel may be sufficiently breathable so that the combustible heat source burns substantially unhindered.

The at least one layer of fiber-reinforced airgel may surround approximately half the length of the aerosol-forming substrate. Advantageously, the fiber-reinforced airgel surrounding the aerosol-forming substrate can reduce the surface temperature of the aerosol-generating article in the aerosol-forming substrate.

The at least one layer of fiber-reinforced airgel may surround the combustible heat source at the downstream end of the combustible heat source. This can advantageously reduce the surface temperature of the aerosol generating article at the portion of the combustible heat source closest to the user during normal operation of the aerosol generating article.

The at least one layer of fiber-reinforced airgel may surround the combustible heat source at the upstream end of the combustible heat source.

The at least one layer of fiber-reinforced airgel may surround the combustible heat source at the upstream end and at the downstream end.

Uncovered parts of a combustible heat source may be referred to as "exposed" parts in this document. The at least one layer of fiber-reinforced airgel according to the present invention may be provided to cover or surround "exposed" or uncoated parts of the combustible heat source.

In some embodiments, a portion of the combustible heat source may be surrounded by at least one additional layer at the upstream end. The at least one additional layer may be a layer of cigarette paper. In these embodiments, the upstream portion of the combustible heat source is an open portion. In other words, the upstream part of the combustible heat source is not covered by the at least one additional layer. In these embodiments, said at least one layer of fiber-reinforced airgel may surround the upstream portion of the combustible heat source. The at least one layer of fiber-reinforced airgel may surround the combustible heat source from the upstream end of at least one additional layer surrounding the upstream portion of the combustible heat source to or around the downstream end of the combustible heat source. Thus, in these embodiments, the combustible heat source may be surrounded substantially along its length by a combination of said at least one additional layer at the downstream end and said at least one layer of fiber-reinforced airgel at the upstream end. In some embodiments, said at least one layer of fiber-reinforced airgel and said at least one additional layer may overlap along the length of the combustible heat source.

Said at least one layer of fiber-reinforced airgel may be isolated from one or more air flow passages such that, in use, air drawn through the aerosol generating article along one or more air flow passages does not come into direct contact with said at least one layer of fiber-reinforced airgel.

In some embodiments, said at least one layer of fiber-reinforced airgel may be separated from said one or more air flow passages such that air drawn through the aerosol generating article along said one or more air flow passages does not directly contact said at least one layer of fiber-reinforced airgel.

In some embodiments, one or more portions of at least one layer of fiber-reinforced airgel may be covered, coated, or encapsulated in a material substantially impermeable to fibers and particles. One or more portions of said at least one layer of fiber-reinforced airgel that are closed, coated or encapsulated in a material substantially impermeable to fibers and particles may be positioned adjacent to air drawn through the aerosol generating article along one or more flow paths air. By closing, covering or sealing, it is possible to isolate air drawn through the aerosol generating article along said one or more air flow passages from the fibers and particles of said at least one layer of fiber reinforced airgel.

In some embodiments, one or more portions of said at least one layer of fiber-reinforced airgel may be covered with a paper layer to isolate said at least one layer of fiber-reinforced airgel from said one or more air flow passages. The paper layer may be disposed on at least one of an inner surface of said at least one fiber-reinforced airgel layer and an outer surface of said at least one fiber-reinforced airgel layer. The paper layer can be located both on the inner and outer surfaces of the said at least one layer of fiber-reinforced airgel. The paper layer may contain laminated paper. The paper layer can be made in a multi-layer configuration with at least one fiber-reinforced airgel layer. The paper layer may only be located on a portion of said at least one fiber-reinforced airgel layer adjacent to the air flow passage.

directly at least one layer of fiber-reinforced airgel may be substantially flame retardant. In the context of this document, the term "combustion resistant" is used to describe a material that remains substantially intact during the ignition and combustion of a combustible heat source. The provision of at least one layer of combustion-resistant fiber-reinforced airgel surrounding at least a portion of the length of the combustible heat source can advantageously prevent the release of fire or smoke from the layer. This can substantially prevent or suppress unwanted emissions or unpleasant odors emitted from the bed when the combustible heat source is burned.

The combustible heat source, the aerosol forming substrate, and the at least one layer of fiber reinforced airgel may be configured to substantially prevent or suppress the temperature rise of the aerosol forming substrate above about 375 ° C during combustion of the combustible heat source. For example, a combustible heat source, an aerosol forming substrate, and said at least one layer of fiber-reinforced airgel can be selected in terms of shape, size, and placement to substantially prevent or suppress the temperature of the aerosol forming substrate above about 375 ° C. during combustion of a combustible heat source. This can maintain the integrity of the aerosol forming substrate. For example, if the aerosol forming substrate contains one or more aerosol forming agents, the aerosol forming agents may be pyrolyzed at temperatures above about 375 ° C. At even higher temperatures, such as when the aerosolizing substrate contains tobacco, the tobacco can burn.

The combustible heat source, the substrate forming the aerosol, and the at least one layer of the fiber-reinforced airgel can be made in such a way that, when the combustible heat source is burning, the temperature of the substrate forming the aerosol is 2 mm from the inner surface of the substrate forming the aerosol. at least about 100 ° C over a period of at least about 6 minutes.

The fiber-reinforced airgel may contain less than about 80 percent by weight of the airgel. The fiber-reinforced airgel may contain less than about 70 percent by weight of the airgel. The fiber-reinforced airgel may contain more than about 20 percent by weight of the airgel. The fiber-reinforced airgel may contain more than about 30 percent by weight of the airgel. The fiber-reinforced airgel may contain from about 20 percent by weight to about 80 percent by weight of the airgel, or from about 40 percent by weight to about 60 percent by weight of the airgel. If the fiber-reinforced airgel contains silica airgel, the fiber-reinforced airgel may contain from about 30 percent by weight to about 40 percent by weight of synthetic amorphous silica. If the fiber-reinforced airgel contains silica airgel, the fiber-reinforced airgel may contain from about 10 percent by weight to about 20 percent by weight methylsilylated silica.

The fiber-reinforced airgel may contain at least about 20 percent by weight fibrous material. The fiber-reinforced airgel may contain at least about 30 percent by weight fibrous material. The fiber-reinforced airgel may contain less than about 70 percent by weight of the fibrous material. The fiber-reinforced airgel may contain less than about 60 percent by weight of the fibrous material. The fiber-reinforced airgel may contain from about 20 percent by weight to about 70 percent by weight of fibrous material, or from about 40 percent by weight to about 50 percent by weight of fibrous material.

The fiber-reinforced airgel may contain from about 30 percent by weight to about 40 percent by weight of synthetic amorphous silica; about 10 percent by weight to about 80 percent by weight methylsilylated silica; from about 40 percent by weight to about 50 percent by weight of the fibrous material.

The fiber-reinforced airgel of the present invention may contain any suitable airgel. Examples of suitable aerogels include, but are not limited to, quartz airgels, metal oxide aerogels, organic and carbon aerogels, nanotube aerogels, metal aerogels, or combinations thereof. If the airgel is a silica airgel, then the airgel may contain one or more of the following: synthetic amorphous silicon dioxide and methylsilylated silicon dioxide.

The fiber-reinforced airgel of the present invention may contain any suitable fibrous material. The fibrous material can contain one or more of any suitable fiber. For example, suitable fibers may include, but are not limited to, glass fibers, silicon fibers, carbon fibers, polymer fibers, metal fibers, and ceramic fibers. The fibers can contain at least one of an organic material or an inorganic material. The fibers can contain a combination of organic and inorganic materials. The fibrous material can be woven. The fibrous material can be non-woven. The fibrous material may contain fiber wool or fiber wool.

The fiber-reinforced airgel may contain a binder.

The fibrous material may contain a binder. Binders are used in some fibrous materials to hold the fibrous material together. The provision of a binder can also improve the mechanical properties of the fibrous material. For example, the binder can make the fibrous material less brittle and more flexible.

The binder can be a cellulose-derived binder. In the context of this document, the term "binder based on cellulose derivatives" is used to describe a binder containing a cellulose derivative. In particular, the cellulose derivative binder may contain a cellulose derivative that is created by adding a specific side group to the cellulose.

Suitable cellulose derivatives include, but are not limited to, carboxymethyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC), hydroxyethyl methyl cellulose (HEC), hydroxyethyl cellulose, cellulose acetate, cellulose ester, and cellulose ether. Preferably, the cellulose derivative binder contains carboxymethyl cellulose.

The binder may contain one or more organic binders such as bitumen, animal and vegetable adhesives, and polymers. The binder may contain one or more inorganic binders such as lime, cement, gypsum, and water glass. If the binder contains one or more polymers, the polymers may contain: acrylic resin, phenolic resin, polyester, epoxy, polyether, polyvinyl alcohol (PVOH), styrene-based, carboxylic acid ether, and polyurethane. The binder may contain one or more of carboxymethyl cellulose (CMC) and bentonite. The binder can be an acrylic binder.

The fiber-reinforced airgel may comprise a ceramic fiber material. The ceramic fibrous material may contain ceramic fibers.

If the fiber-reinforced airgel contains a ceramic fiber material, the ceramic fiber material may contain crystalline ceramic materials. The ceramic fibrous material may contain non-crystalline ceramic materials. The ceramic fibrous material can be amorphous. The ceramic fibrous material can be semi-crystalline. Ceramic fibrous material can be crystalline.

In the context of this document, the term "ceramic fibrous material" includes glasses. In the context of this document, the term "glass" is used to describe materials whose glass transition occurs at the glass transition temperature. Typically, the term "glass" in the context of this document is used to describe non-crystalline or amorphous solid materials. However, the term "glass" also includes materials containing crystalline components and non-crystalline components. Glass materials containing both crystalline and non-crystalline components can be called “glass-ceramic” materials.

The properties of glass materials according to the present invention can be determined by the glass formation method. In the context of this document, the term "glass" includes glasses formed by any suitable method. Suitable methods for making glasses include: melt quenching; physical vapor deposition; solid phase reactions, including thermochemical and mechanochemical reactions; liquid phase reactions such as the sol-gel method; irradiation of crystalline solids, for example, radiation amorphization; and also amorphization under pressure (i.e., formation under high pressure).

In some embodiments, the ceramic fibrous material may comprise glass. The ceramic fibrous material may contain glass fibers. Glass fibers may contain glass ceramic material. The ceramic fibrous material may contain continuous glass fibers.

In some embodiments, the ceramic fibrous material may be glass-free. In other words, the ceramic fibrous material can contain any ceramic materials other than glasses. Ceramic fibrous material may not be glass material. Ceramic fiber material may not contain fiberglass. In these embodiments, the ceramic fibrous material typically comprises crystalline ceramic materials.

In some embodiments, the fibrous material may contain biosoluble fibers. In the context of this document, the term "bio-soluble" is used to describe a material that dissolves in a biological system, for example, in a biological system in the human body. The bio-solubility of a material in a particular biological system can differ significantly from the bio-solubility of a material in water. In the context of this document, a substance can be considered bio-soluble if at least 0.1 g of this substance is dissolved in 100 ml of a biological system solvent. Likewise, a substance can be considered bio-soluble if less than 0.1 g of the material is dissolved in 100 ml of a biological system solvent. Typically, the biosoluble fiber of the present invention is soluble in the respiratory system of the wearer when the fiber is inhaled. In other words, the biosoluble material of the present invention generally dissolves in the respiratory system of the wearer when the fiber is inhaled. The bio-soluble fibers of the present invention may be soluble in the human alveolar environment.

The bio-soluble material can be any suitable bio-soluble material. Suitable bio-soluble materials include alkaline earth metal silicate wool and high alumina, low silicon wool.

In some embodiments of the present invention, the fiber-reinforced airgel may have about 100 percent by weight alkaline earth metal silicate wool.

The fiber-reinforced airgel may contain any other suitable reinforcing material. For example, the fiber-reinforced airgel may contain polymer fibers such as polyamides and polyimides. The fiber-reinforced airgel can be further strengthened by additional means, such as solid particle hardening. For example, a fiber-reinforced airgel can be reinforced with carbon black particles. The fiber-reinforced airgel may also contain any other suitable constituents, including but not limited to titanium dioxide, aluminum hydroxide, and pigments that may contain iron and manganese.

Suitable fiber-reinforced aerogels include Pyrogel® XT-E and Pyrogel® XT-F, both of which are manufactured by Aspen Aerogels®.

The at least one layer of fiber-reinforced airgel can be of any suitable thickness. Typically, said at least one layer of fiber-reinforced airgel is a thin layer. The thickness of said at least one layer of fiber-reinforced airgel may be at least about 0.25 millimeters or at least about 0.5 millimeters. The thickness of said at least one layer of fiber-reinforced airgel may be less than about 10 millimeters or less than about 5 millimeters. The at least one layer of fiber-reinforced airgel may have a thickness ranging from about 0.25 millimeters to about 10 millimeters, or from about 0.5 millimeters to about 5 millimeters.

The aerosol generating article of the present invention comprises an aerosol forming substrate. In the context of this document, the term "aerosol forming substrate" is used to describe a substrate that has the ability to release volatile compounds upon heating that can form an aerosol. Aerosols generated from aerosol-forming substrates in aerosol-generating articles of the present invention may be visible or invisible and may contain vapors (e.g., fine particles of gaseous substances, which are usually liquid or solid at room temperature), as well as gases and liquid droplets of condensed vapors.

The aerosol-forming substrate can be solid. The aerosol-forming substrate can be solid at room temperature.

The aerosol-forming substrate contains at least one aerosol-forming agent and at least one material capable of responding to heating by emitting volatile compounds.

Said at least one aerosol forming agent may be any suitable known compound or mixture of compounds that, when used, promotes the formation of a dense and stable aerosol and is substantially resistant to thermal degradation at the operating temperature of the aerosol generating article. Suitable aerosols are well known in the art and include, for example, polyhydric alcohols, esters of polyhydric alcohols such as glycerol mono-, di- or triacetate, and aliphatic esters of mono-, di- or polycarboxylic acid such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Exemplary aerosol forming agents for use in aerosol generating articles of the present invention are polyhydric alcohols or mixtures thereof such as triethylene glycol, 1,3-butanediol, and glycerol.

The material capable of releasing volatile compounds in response to heating may be a filler of plant material, for example, a filler of a homogenized material of plant origin. For example, the aerosol-forming substrate can contain one or more plant-derived materials, including, but not limited to: tobacco; tea, such as green tea; peppermint; laurel; eucalyptus; basil; sage; verbena and tarragon. The plant material may contain additives, including, but not limited to, humectants, fragrances, binders, and mixtures thereof. The plant material can be composed primarily of tobacco material, optionally of homogenized tobacco material.

Aerosol generating articles of the present invention may contain aerosol forming substrates containing nicotine. For example, aerosol generating articles of the present invention comprise aerosol forming substrates containing tobacco.

The aerosol-forming substrate may be surrounded by the filter filament.

An aerosol generating article of the present invention comprises a combustible heat source positioned to heat the aerosol forming substrate and isolated from one or more air flow passages.

A combustible heat source may contain a body of combustible material. The body of combustible material can have a substantially constant diameter. The body of combustible material can have a constant diameter along its length. This can advantageously simplify the processes involved in the manufacture of a combustible heat source and aerosol generating article. In some embodiments, the body of combustible material may form a substantially circular cylindrical body having a substantially constant diameter along its length.

The combustible heat source can be a carbonaceous combustible heat source. In the context of this document, the term "carbonaceous" is used to describe a combustible heat source containing carbon. Preferably, carbonaceous combustible heat sources for use in aerosol generating articles of the present invention have a carbon content of at least about 35 percent, more preferably at least about 40 percent, most preferably at least about 45 percent on a dry weight basis. 30 combustible heat source.

The combustible heat sources of the present invention can be a carbon-based combustible heat source. In the context of this document, the term "carbon-based heat source" is used to describe a heat source containing mainly carbon.

Carbon-based combustible heat sources for use in aerosol generating articles of the present invention may have a carbon content of at least about 50 percent, preferably at least about 60 percent, more preferably at least about 70 percent, most preferably at least about 80 percent dry weight of a carbon-based combustible heat source.

The combustible heat source of the present invention is isolated from one or more air flow passages through the aerosol generating article. In the context of this document, the term "air flow passage" is used to describe the route along which air can be drawn through the aerosol generating article for inhalation by the user. In the context of this document, the terms "upstream" and "downstream" are used to describe the relative directions and positions of the components of an aerosol generating article in relation to directing air flow through one or more air flow passages when a user puffs on the article. generating aerosol.

Isolating the combustible heat source from one or more air flow passages of the aerosol generating article can substantially prevent or suppress activation of combustion of the combustible heat source during a puff by the user. This can substantially prevent or suppress jumps in the temperature of the aerosol-forming substrate when the user puffs on the aerosol-generating article. This can substantially prevent or suppress combustion or pyrolysis of the aerosol-forming substrate under intense puff conditions. This can substantially prevent or suppress changes in the composition of the aerosol generated by the aerosol generating article due to the user's puff behavior.

Isolating a combustible heat source from one or more air flow passages can also substantially prevent or suppress combustion and decomposition products and other materials resulting from the ignition and combustion of the combustible heat source from entering the air drawn through the aerosol generating article along one or multiple passages for air flow.

The insulated combustible heat source of the present invention may comprise a continuous heat source. In the context of this document, the term "solid" is used to describe a combustible heat source in which air drawn in through an aerosol generating article for inhalation by a user does not pass through the air flow channels along the combustible heat source. Essentially, heat exchange between the continuous combustible heat source and the aerosol-forming substrate is predominantly due to conductive heat exchange.

Due to the lack of air flow channels passing through the combustible heat source, convective heat exchange between the combustible heat source and the aerosol forming substrate is reduced or minimized. By reducing convective heat transfer between the combustible heat source and the aerosol-forming substrate, it is possible to substantially prevent or suppress temperature jumps of the aerosol-forming substrate during a puff by the user. This can substantially prevent or suppress combustion or pyrolysis of the aerosol-forming substrate under intense puff conditions. This can substantially prevent or suppress changes in the composition of the aerosol generated by the aerosol generating article due to the user's puff behavior. It can also substantially prevent or suppress combustion and decomposition products and other materials resulting from the ignition and combustion of a combustible heat source from entering the air drawn through the aerosol generating article along one or more air flow passages.

The insulated combustible heat source of the present invention may comprise a non-continuous heat source. In the context of this document, the term "discontinuous" is used to describe a heat source in which air drawn in through an aerosol-generating article for inhalation by a user passes through one or more air flow channels along a combustible heat source. As such, heat exchange between the discontinuous combustible heat source and the aerosol-forming substrate can occur by both conductive heat transfer and convective heat transfer along one or more air flow channels.

In the context of this document, the term “air flow channel” is used to describe a channel along the length of a combustible heat source through which air can be drawn downstream for inhalation by a user. As such, the aerosol generating article of the present invention may not include one or more air flow channels.

One or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol forming substrate may include a first baffle that abuts one or both of the proximal end of the combustible heat source and the distal end of the aerosol forming substrate. The first baffle can help isolate the combustible heat source from one or more air flow passages of the aerosol generating article. The first baffle can reduce the maximum temperature to which the aerosol forming substrate is exposed during ignition or combustion of the combustible heat source, and can substantially prevent or suppress thermal degradation or combustion of the aerosol forming substrate during use of the aerosol generating article.

In the context of this document, the term "non-combustible" is used to describe a material that is substantially non-combustible at temperatures reached by a combustible heat source during its combustion and ignition.

In the context of this document, the term "airtight" is used to describe a material that substantially prevents or suppresses the passage of air through it.

The first baffle may be adhered or otherwise attached to one or both of the proximal end of the combustible heat source and the distal end of the aerosol forming substrate.

The first baffle contains a first barrier coating provided on the inner surface of the combustible heat source. In such embodiments, the first baffle may comprise a first barrier covering provided at least substantially over the entire interior surface of the combustible heat source. The first baffle may comprise a first barrier coating provided on the entire inner surface of the combustible heat source. The first barrier coating can be formed and applied to the inner surface of the combustible heat source using any suitable method, such as those described in WO-A1-2013120855.

Depending on the desired characteristics and properties of the aerosol generating article, the first baffle may have low thermal conductivity or high thermal conductivity. In certain embodiments, the first baffle may have a thermal conductivity ranging from about 0.1 W / m⋅K to about 200 W / m⋅K.

The thickness of the first baffle can be appropriately adjusted to provide good aerosol generation characteristics. In certain embodiments, the first baffle may have a thickness of about 10 microns to about 500 microns.

The first baffle can be made of one or more suitable materials that are substantially thermally stable and non-combustible at temperatures reached by the combustible heat source during ignition and combustion. Suitable materials are known in the art and include, but are not limited to, clays (such as bentonite and kaolinite), glasses, minerals, ceramics, resins, metals, and combinations thereof.

Materials from which the first partition can be made include clays and glass. Other materials from which the first baffle can be formed include copper, aluminum, stainless steel, alloys, alumina (Al ₂ O ₃ ), resins, and mineral adhesives.

If the first baffle contains a metal or alloy such as copper, aluminum, stainless steel, then the first barrier coating can advantageously act as a thermal bond between the combustible heat source and the aerosol forming substrate. This can improve conductive heat transfer from the combustible heat source to the aerosol forming substrate.

The aerosol generating article may further comprise one or more air inlets downstream of the proximal end of the combustible heat source. In some embodiments, one or more air inlets are located between the proximal end of the combustible heat source and the proximal end of the aerosol generating article. One or more air inlets can be located so that air can be drawn into one or more air flow passages of the aerosol generating article through one or more air inlets without being drawn through a combustible heat source. This can substantially prevent or suppress jumps in the temperature of the aerosol-forming substrate during puffs by the user.

One or more air inlets may include a suitable air inlet through which air can be drawn into the aerosol generating article. For example, suitable air inlets include openings, slots, slots, or other openings. The number, shape, size and location of the air inlets can be appropriately adjusted to provide good aerosol generation characteristics.

One or more air inlets may be located anywhere between the proximal end of the combustible heat source and the proximal end of the aerosol generating article. One or more air inlets can be located on the aerosol-forming substrate. One or more air inlets may be located between the distal end of the aerosol-forming substrate and the proximal end of the aerosol-forming substrate. If one or more air inlets are located on the aerosol-forming substrate and the aerosol-forming substrate contains a filter phycella, the filter phycella may have one or more openings to allow air to pass into the aerosol-forming substrate. One or more openings can be slots, slots, or other suitable openings through which air can be drawn into the aerosol-forming substrate. The number, shape, size and location of the holes can be properly adjusted to provide good aerosol generation characteristics.

A combustible heat source may contain one or more channels for air flow. The combustible heat source can be a non-continuous combustible heat source. One or more air flow channels can extend along the length of the combustible heat source. One or more air flow passages may form part of one or more air flow passages of the aerosol generating article.

If the combustible heat source contains one or more channels for air flow in the article generating the aerosol, then one or more non-combustible, substantially airtight baffles between the combustible heat source and the substrate forming the aerosol may further comprise a second baffle between the combustible heat source and one or several channels for the air flow of a combustible heat source.

The second baffle can improve the insulation of the combustible heat source from one or more air flow passages of the aerosol generating article. The second baffle can limit the maximum temperature to which the aerosol forming substrate is exposed during the ignition or combustion of the combustible heat source and thus help prevent or reduce thermal degradation or combustion of the aerosol forming substrate during use of the aerosol generating article.

The second baffle can be glued or otherwise attached to the combustible heat source.

The second baffle contains a second barrier coating provided on the inner surface of one or more air flow channels. The second baffle may comprise a second barrier coating provided at least substantially over the entire inner surface of one or more air flow channels. The second baffle may comprise a second barrier coating provided on the entire inner surface of one or more air flow channels.

The second barrier coating can be made by inserting the liner into one or more air flow channels. For example, if one or more airflow passages provide one or more airflow passages passing through the interior of a combustible heat source, then a non-combustible, substantially airtight hollow tube may be inserted into each of the one or more airflow passages.

The second baffle may advantageously substantially prevent or suppress the ingress of combustion and decomposition products into the air drawn in downstream along one or more air flow channels during the ignition and combustion of a combustible heat source of aerosol generating articles of the present invention.

Depending on the desired characteristics and properties of the aerosol generating article, the second baffle may have low thermal conductivity or high thermal conductivity. The second baffle may have low thermal conductivity.

The thickness of the second baffle can be appropriately adjusted to provide good aerosol generation characteristics. In some embodiments, the second baffle may have a thickness ranging from about 30 microns to about 200 microns. In one embodiment, the second baffle is from about 30 microns to about 100 microns thick.

The second baffle can be made of one or more suitable materials that are substantially thermally stable and non-combustible at temperatures reached by the combustible heat source during ignition and combustion. Suitable materials are known in the art and include, but are not limited to, for example: clays; metal oxides such as iron oxide, alumina, titanium oxide, silica, silica-alumina, zirconia and cerium oxide; zeolites; zirconium phosphate; and other ceramic materials or combinations thereof.

Materials from which the second baffle can be made include clays, glasses, aluminum, iron oxide, and combinations thereof. If desired, catalytic ingredients such as ingredients that promote the oxidation of carbon monoxide to carbon dioxide can be included in the second baffle. Suitable catalytic ingredients include, but are not limited to, for example, platinum, palladium, transition metals and their oxides.

Where aerosol generating articles of the present invention comprise a first baffle between the downstream end of the combustible heat source and the upstream end of the aerosol forming substrate and a second baffle between the combustible heat source and one or more air flow ducts along the combustible source heat, the second partition can be formed from the same material or materials as the first partition, or a different material or materials.

If the second baffle contains a second barrier coating formed on the inner surface of one or more air flow channels, then the second barrier coating can be applied to the inner surface of one or more air flow channels in any suitable manner, such as those described in US A-5,040,551 and WO-A1-2013120855.

The aerosol generating article may further comprise one or more additional layers surrounding at least the proximal portion of the combustible heat source and the distal portion of the substrate forming the aerosol. One or more additional layers may comprise at least one of: a heat-conducting element for transferring heat from a combustible heat source to an aerosol-forming substrate; and a layer of cigarette paper.

The heat transfer element can only surround the distal part of the aerosol-forming substrate. The heat transfer element may surround substantially the length of the aerosol-forming substrate. The heat transfer element may be in direct contact with at least one of a combustible heat source and an aerosol-forming substrate. The heat transfer element may not be in direct contact with either the combustible heat source or the aerosol-forming substrate.

The heat transfer element can provide thermal coupling between the combustible heat source and the aerosol-forming substrate. The heat transfer element can be substantially flame retardant.

Suitable heat transfer members may include: metal foil wrappers or metal alloy foil wrappers. Metal foil wrappers may include: aluminum foil wrappers, steel foil wrappers, iron foil wrappers, and copper foil wrappers. The heat transfer element may comprise an aluminum tube.

The proximal part of the combustible heat source, surrounded by the heat transfer member, has a length of about 2 millimeters to about 8 millimeters, or a length of about 3 millimeters to about 5 millimeters.

The distal portion of the combustible heat source, not surrounded by the heat transfer element, has a length of about 4 millimeters to about 15 millimeters, or a length of about 4 millimeters to about 8 millimeters.

The layer of cigarette paper may surround at least the proximal portion of the combustible heat source, the length of the aerosol-forming substrate, and any other components of the aerosol-generating article located in the vicinity of the aerosol-forming substrate. The layer of cigarette paper may surround substantially the length of the combustible heat source. If the layer of cigarette paper surrounds substantially the length of the combustible heat source, the layer of cigarette paper may be provided with ventilation, such as perforations, holes or slots, on the combustible heat source to allow air to pass through the layer of cigarette paper to the combustible heat source. The number, shape, size and location of the openings can be properly adjusted to provide good aerosol generation characteristics. The cigarette paper layer can be wrapped tightly around the combustible heat source and aerosol forming substrate such that the cigarette paper layer captures and retains the combustible heat source and aerosol forming substrate when assembling the aerosol generating article.

At least one layer of the fiber-reinforced airgel may be a radially outer layer. If the aerosol generating article contains one or more additional layers, then the radially outer layer of the fiber-reinforced airgel may overlap at least a portion of the one or more additional layers. In other words, said one or more additional layers may be located between the combustible heat source and at least one layer of fiber-reinforced airgel. For example, if the aerosol generating article contains an additional layer containing a heat transfer element, then the heat transfer element may be a radially inner layer, and said at least one layer of fiber-reinforced airgel may be a radially outer layer surrounding at least a portion of the heat transfer element.

In the context of this document, the terms "radially outer" and "radially inner" are used to indicate the relative distances of the components of the aerosol generating article from the longitudinal axis of the aerosol generating article. In the context of this document, the term "radial" is used to describe a direction perpendicular to the longitudinal axis of the aerosol generating article extending in the direction between the proximal end and the distal end of the aerosol generating article.

Said one or more additional layers may be radially outer layers. Said one or more additional layers may overlap at least a portion of said at least one fiber-reinforced airgel layer.

The at least one layer of fiber-reinforced airgel may be attached or secured to one or more other components or parts of the aerosol generating article. The at least one layer of fiber-reinforced airgel may be attached to any suitable component of the aerosol generating article. For example, said at least one layer of fiber-reinforced airgel may be attached to at least one of a combustible heat source, an aerosol-forming substrate, and one or more additional layers. The at least one layer of fiber-reinforced airgel may be attached to one or more components of the aerosol-generating article by any suitable means. The at least one layer of fiber-reinforced airgel can be attached using an adhesive. Suitable adhesives such as silicate glue can have high heat resistance. If said one or more additional layers are radially outer layers, then one or more additional layers can be tightly wrapped around at least part of at least one layer of fiber-reinforced airgel.

In some embodiments, said at least one layer of fiber-reinforced airgel may be inseparable from a combustible heat source. In the context of this document, the term "inseparable" is used to describe a layer that is in direct contact with a combustible heat source and is attached to a combustible heat source without the help of an extraneous adhesive or other intermediate bonding material.

In some embodiments, the at least one fiber-reinforced airgel layer may be formed from a strip of fiber-reinforced airgel having opposite ends. A strip of fiber-reinforced airgel may be wrapped around a combustible heat source such that opposite ends of the strip overlap. Superimposed opposite ends of the strip may be bonded to each other using an adhesive or any other suitable means. This can adhere at least one layer of fiber-reinforced airgel to the combustible heat source.

In some embodiments, the intermediate layer may be located between at least one layer of fiber-reinforced airgel and at least one of a combustible heat source, an aerosol forming substrate, and one or more additional layers. The intermediate layer may be adjacent to said at least one layer of fiber-reinforced airgel. The intermediate layer may contact at least one layer of fiber-reinforced airgel. The intermediate layer may be located radially within at least one layer of fiber-reinforced airgel.

The intermediate layer can be an adhesive layer. The adhesive layer can contain any suitable adhesive. Suitable adhesives such as silicate glue can have high heat resistance. The adhesive layer may be sandwiched between at least one layer of fiber-reinforced airgel and a combustible heat source, and may adhere at least one layer of fiber-reinforced airgel to the combustible heat source. The adhesive layer may be sandwiched between at least one layer of fiber-reinforced airgel and one or more additional layers, and may attach at least one layer of fiber-reinforced airgel to one or more additional layers. The adhesive layer may be sandwiched between at least one layer of fiber-reinforced airgel and the aerosol-forming substrate and may adhere at least one layer of fiber-reinforced airgel to the aerosol-forming substrate.

In some embodiments, at least one fiber-reinforced airgel layer can be formed from a strip of fiber-reinforced airgel having opposite ends. A strip of fiber-reinforced airgel can be wrapped around a combustible heat source so that opposite ends of the strip touch but do not overlap. The adhesive layer may be on the side of the strip facing the combustible heat source, at least at opposite ends of the strip. The adhesive layer may adhere the strip of fiber-reinforced airgel to a combustible heat source at at least opposite ends of the strip.

The aerosol generating article may comprise a heat transfer component located between the combustible heat source and the substrate forming the aerosol. The heat transfer component may be the first baffle as described above. The aerosol generating article may include a heat transfer component and a first baffle. The thermally conductive component can be made of a material similar to that of the thermally conductive element. The aerosol generating article may contain a heat transfer component and a heat transfer element. Providing at least one of the heat transfer element and the heat transfer component can improve conductive heat transfer between the combustible heat source and the aerosol forming substrate.

The aerosol generating article may further comprise any other suitable components. For example, an aerosol generating article may comprise at least one of: a transfer member; an aerosol cooling element; dividing element; and a mouthpiece. One or more additional components can be positioned coaxially with the combustible heat source and the aerosol forming substrate. One or more additional components may be located in the vicinity of the aerosol forming substrate. One or more additional components can be arranged in any suitable order. The aerosol generating article may further comprise: a transfer member adjacent to the proximal end of the aerosol forming substrate; an aerosol cooling element adjacent to the proximal end of the transfer element; a spacer element adjacent to the proximal end of the aerosol cooling element; and a mouthpiece adjacent to the proximal end of the spacer member.

In the context of this document, the terms "near" and "far" are used to describe the relative positions of components or parts of components of the aerosol generating articles according to the present invention. The proximal end of an aerosol-generating article component is the end of that component closest to the mouth-to-mouth end of the aerosol-generating article, and the distal end of an aerosol-generating article component is the end of the component farthest from the mouth-to-mouth end , a product that generates an aerosol. Typically, a combustible heat source is located at the distal end of the aerosol generating article.

According to a second aspect of the present invention, there is provided a method of forming an aerosol generating article according to the first aspect of the present invention. The method includes: positioning a combustible heat source to heat an aerosol-forming substrate; providing one or more air flow paths along which air can be drawn through the aerosol generating article for inhalation by a user; isolating the combustible heat source from said one or more air flow passages so that, in use, air drawn in through the aerosol generating article along said one or more air flow passages does not come into direct contact with the combustible heat source; and surrounding at least a portion of the length of the combustible heat source with at least one layer of fiber-reinforced airgel.

In some embodiments, the step of surrounding at least a portion of the length of the combustible heat source with said at least one layer of fiber-reinforced airgel may include: providing a strip of fiber-reinforced airgel having opposite ends; wrapping the strip around the combustible heat source so that the combustible heat source is surrounded by said at least one layer of fiber-reinforced airgel; overlapping opposite ends of the strip; and joining the superimposed ends to join at least one layer of fiber-reinforced airgel to a combustible heat source.

The overlapping ends of the fiber-reinforced airgel strip may be secured to each other using any suitable means. For example, the overlaid ends of the fiber-reinforced airgel strip are bonded to each other using an adhesive. Suitable adhesives must be highly heat resistant and contain a silicate adhesive.

In some embodiments, the step of surrounding at least a portion of the length of the combustible heat source with at least one layer of fiber-reinforced airgel may include: providing a strip of fiber-reinforced airgel having opposite ends; applying an adhesive layer to one side of the strip at least on each opposite end; placing a strip with an adhesive layer facing a combustible heat source; wrapping the strip around the combustible heat source such that at least a portion of the length of the combustible heat source is surrounded by at least one layer of fiber-reinforced airgel; contact of opposite ends of the strip without overlapping opposite ends; and attaching the strip to the combustible heat source by means of an adhesive layer.

In some embodiments, the implementation of at least one layer of fiber-reinforced airgel may be laminated with an additional layer, such as a layer of cigarette paper. At least one layer of fiber-reinforced airgel may be laminated with an additional layer before at least one layer of fiber-reinforced airgel is applied to the combustible heat source. A strip of multi-ply paper containing at least one layer of fiber-reinforced airgel and an additional layer can be wrapped around a combustible heat source in the same manner as a strip of fiber-reinforced airgel. In some embodiments, the multi-ply paper may be positioned such that at least one layer of fiber-reinforced airgel faces a combustible heat source. In other words, at least one layer of fiber-reinforced airgel may be positioned radially within the additional layer. In some embodiments, the implementation of the multi-ply paper may be positioned such that the additional layer faces a combustible heat source.

The present invention will be further described solely by way of example, with reference to the accompanying drawings, in which:

Fig. 1 schematically shows a first embodiment of an aerosol generating article according to the present invention, which comprises a continuous combustible heat source;

Figure 2 shows the temperature profile of the aerosol generating article of Figure 1 in a first position;

Figure 3 shows the temperature profile of the aerosol generating article of Figure 1 in a second position;

Figure 4 shows the temperature profile of the aerosol generating article of Figure 1 in a third position; and

Fig. 5 is a schematic diagram of a second embodiment of an aerosol generating article according to the present invention, which comprises a discontinuous combustible heat source.

Figure 1 schematically shows an article 2 that generates an aerosol. The aerosol generating article 2 contains a combustible heat source 3. The combustible heat source 3 comprises a substantially circular cylindrical body of carbonaceous material having a length of approximately 10 millimeters. The combustible heat source 3 is a continuous heat source. In other words, the combustible heat source 3 does not contain any channels for air passing through it.

The aerosol-generating article 2 contains an aerosol-forming substrate 4. The aerosol-forming substrate 4 is located at the proximal end of the combustible heat source 3. The aerosol-forming substrate 4 comprises a substantially circular cylindrical rod of tobacco material 18 surrounded by a filter filament 19.

A non-combustible, substantially airtight first baffle 6 is positioned between the proximal end of the combustible heat source 3 and the distal end of the aerosol-forming substrate 4. The first baffle 6 contains an aluminum foil disc. The first baffle 6 also forms a heat conductive component between the combustible heat source 3 and the aerosol-forming substrate 4 for conducting heat from the inner surface of the combustible heat source 3 to the outer surface of the aerosol-forming substrate 4.

The heat transfer element 9 surrounds the proximal portion of the combustible heat source 3 and the distal portion of the aerosol-forming substrate 4. The heat-conducting element 9 contains an aluminum foil tube. The heat-conducting element 9 is in direct contact with the proximal part of the combustible heat source 3 and the ficelle 19 of the filter of the substrate 4 that forms the aerosol.

The aerosol generating article 2 further comprises various other components located in the vicinity of the aerosol forming substrate 4, including: a transfer member 11 located at the proximal end of the aerosol forming substrate 4; an aerosol cooling element 12 located at the proximal end of the transfer element 11; a spacer element 13 located at the proximal end of the aerosol cooling element 11; and a mouthpiece 10 located at the proximal end of the spacer 13.

The components of the aerosol generating article 2 are wrapped in a layer of cigarette paper 7. The layer of cigarette paper 7 surrounds the heat transfer member 9, but does not extend beyond the distal end of the heat transfer member 9 along the distal portion of the combustible heat source 3.

According to the present invention, the aerosol generating article 2 further comprises a layer of fiber-reinforced airgel 5. The layer of fiber-reinforced airgel 5 surrounds substantially the length of the combustible heat source 3 and the distal portion of the cigarette paper layer 7, the heat transfer element 9 and the aerosol-forming substrate 4. In other words, the fiber-reinforced airgel layer 5 is a radially outer layer at the distal end of the aerosol-generating article 2.

The layer of fiber-reinforced airgel 5 contains silica airgel and fibrous material containing continuous glass fibers. The fiber-reinforced airgel contains about 35 percent by weight synthetic amorphous silica, about 15 percent by weight methylsilylated silicon and about 45 percent by weight continuous glass fibers.

The plurality of air inlets 8 are located on the aerosol-forming substrate 4 to allow ambient air to be drawn into the aerosol-generating article 2. The air inlets 8 comprise a plurality of perforations in the cigarette paper layer 7 and in the lower filamentous layer 19 that surrounds the aerosol-forming substrate 4. Air inlets 8 are located between the outer surface and the inner surface of the aerosol-forming substrate 4.

When the user puffs on the mouthpiece 10 of the aerosol generating article 2, ambient air can be drawn into the aerosol generating article 2 through the air inlets 8. Air drawn into the aerosol-generating article 2 can flow along the air flow path of the aerosol-generating article 2 from the air inlets 8 through the aerosol-forming substrate 4, the conveying element 11, the cooling element 12 and the separating element 13 to the mouthpiece 10 and exits the mouthpiece 10 for inhalation by the user. The main direction of air flow through the aerosol generating article 2 is indicated by arrows.

In use, the user can ignite the combustible heat source 3 by exposing the combustible heat source 3 to an external heat source such as a lighter. The combustible heat source 3 can ignite and burn, and heat can be transferred from the combustible heat source 3 to the aerosol-forming substrate 4 by passing through the heat-conducting component 6 and the heat-conducting element 9. Volatile compounds can be released from the heated aerosol-forming substrate 4. The user can puff on the mouthpiece 10 of the aerosol generating article 2 by drawing ambient air into the air flow passage of the aerosol generating article 2 through the air inlets 8. The vapor from the heated aerosol forming substrate 4 can be entrained by air drawn through the aerosol forming substrate 4 and can be drawn with the air towards the mouthpiece 10. When the steam is drawn towards the mouthpiece 10, the vapor can be cooled to create the aerosol. The aerosol can be drawn from the mouthpiece 10 and delivered to the user for inhalation.

It will be understood that the substantially airtight first baffle 6 blocks air being drawn through the combustible heat source 3 into the aerosol-forming substrate 4. Thus, the first baffle 6 substantially isolates the air flow passage of the aerosol generating article 2 from the combustible heat source 3.

In this embodiment, the fiber-reinforced airgel layer 5 extends over a small portion of the distal end of the aerosol forming substrate 4. Essentially, the fiber-reinforced airgel layer 5 is spaced from the air inlets 8. This distance substantially isolates the fiber-reinforced airgel layer 5 from the air inlets 8 so that air drawn through the air flow passage of the aerosol-generating article 2 does not contact the fiber-reinforced airgel layer 5.

It will be understood that, in some embodiments, the fiber-reinforced airgel layer may be in close proximity to the air inlets. In these embodiments, portions of the fiber-reinforced airgel layer in close proximity to the air inlets may be coated with materials substantially impermeable to fibers and particles. This can substantially insulate portions of the fiber-reinforced airgel layer in close proximity to the air inlets such that air drawn through the air flow passage of the aerosol-generating article does not contact the fiber-reinforced airgel layer.

Experimental data were collected to determine the temperature of combustible heat sources and aerosol forming substrates of various aerosol generating articles, like the aerosol generating articles 2 shown in FIG. 1, during the combustion period of the combustible heat source. Each aerosol generating article tested contained a different layer of material surrounding substantially the length of the combustible heat source. In particular, the experimental data were collected product generating an aerosol containing the layer reinforced airgel (AeroZero ^®, manufactured by Blueshift International Materials, Inc.), substantially surrounding the heat source fuel length fibroarmirovannogo airgel layer (Pyrogel ^® XT-F, produced by Aspen Aerogels, Inc.) surrounding substantially the length of the combustible heat source, and for articles without a layer of material surrounding substantially the length of the combustible heat source. Figures 2-4 show graphs of experimental temperature measurements over time at three different locations on different aerosol-generating products.

Figure 2 shows the temperature measured at a position 2 millimeters from the distal end of the combustible heat source, which corresponds to the position T ₁ shown in Figure 1. In other words, FIG. 2 shows the temperature at the far end of the combustible heat source.

Figure 3 shows the temperature measured at a position 5 millimeters from the distal end of the combustible heat source, which corresponds to the position T ₂ shown in Figure 1. In other words, FIG. 3 shows the temperature at a position approximately midway along the length of the combustible heat source.

FIG. 4 shows the temperature measured at a position 11 millimeters from the distal end of the combustible heat source, which corresponds to position T ₃ in FIG. 1. In other words, FIG. 4 shows the temperature at the distal end of the aerosol forming substrate.

All temperature profiles were measured using electronic temperature sensors embedded approximately 2 millimeters deep into the relevant components of the aerosol generating products.

In FIGS. 2, 3 and 4, the "AeroZero" line at 20 shows the temperature profile of an aerosol generating article with an unreinforced airgel layer surrounding substantially the length of the combustible heat source.

In Figures 2, 3 and 4, the Pyrogel XTF line at 21 shows the temperature profile of an aerosol generating article with a layer of fiber reinforced airgel surrounding substantially the length of a combustible heat source of the present invention.

In Figs. 2, 3 and 4, the "SMAR" line at 22 shows the temperature profile of an aerosol generating article without a layer of material substantially surrounding the length of the combustible heat source.

For aerosol generating articles having a layer of material surrounding substantially the length of the aerosol generating article, temperature profiles substantially similar to or greater than the temperature profile of the aerosol generating article are desired, without a layer of material substantially surrounding the length of the combustible heat source, indicated by 22. This shows that the material layer does not substantially suppress combustion of the combustible heat source.

As shown in FIGS. 2, 3 and 4, the temperature 20 of the aerosol generating article having an unreinforced airgel layer surrounding substantially the length of the combustible heat source is below the temperature 22 of the aerosol generating article without a layer of material surrounding substantially the length of the combustible heat source. , in all three places of the aerosol generating product, during the entire combustion time of the combustible heat source.

Surprisingly, as shown in FIGS. 2, 3 and 4, the temperature 21 of the aerosol generating article having a layer of fiber-reinforced airgel surrounding substantially the length of the combustible heat source is substantially similar to the temperature 22 of the aerosol generating article without a layer of material surrounding substantially the length of the combustible heat source, at all three locations of the aerosol generating article, during most of the combustion time of the combustible heat source. Moreover, the temperature 21 of the aerosol generating article having a layer of fiber-reinforced airgel surrounding substantially the length of the combustible heat source is actually higher than the temperature 22 of the article generating the aerosol, with no layer of material surrounding substantially the length of the combustible heat source at all three locations. aerosol generating product at the end of an aerosol generating session.

These unexpected results indicate that the provision of at least one layer of fiber-reinforced airgel surrounding substantially the length of the combustible heat source, advantageously, does not substantially prevent the combustible heat source from burning. In practice, providing a layer of fiber-reinforced airgel can increase the temperature of the combustible heat source towards the end of the combustion time of the combustible heat source, which can increase the amount of time that aerosol is generated in the aerosol generating article and thus prolong the aerosol generation session for the user.

Aerosol generating articles according to the present invention were tested by observing their effect after placing them on Whatman paper sheets after ignition of a heat source. For example, aerosol generating products were exposed for 24 hours to approximately 23 ° C ± 3 ° C and 55% ± 5% RH. The aerosol generating products exposed to the specified conditions were ignited using an electric lighter and left to burn for 3 minutes. After 3 minutes, the aerosol generating products were placed on a stack of Whatman paper for 8 minutes. After 8 minutes, the sheets of Whatman paper were examined. It was observed that the aerosol generating article having a layer of fiber-reinforced airgel surrounding substantially the length of the combustible heat source did not form a hole on any of the Whatman paper, but left a small darkened area on the top sheet of the paper. This result indicates that the presence of a fiber-reinforced airgel layer surrounding substantially the length of the combustible heat source reduces the surface temperature in the vicinity of the heat source.

Fig. 5 is a schematic diagram of a second embodiment of an aerosol generating article according to the present invention. The aerosol generating article 102 is substantially similar to the aerosol generating article 2 shown in FIG. 1. The aerosol generating article 102 includes a combustible heat source 103, a substrate 104 forming an aerosol, a fiber-reinforced airgel layer 105, and a cigarette paper layer 107, arranged similarly to corresponding components of the aerosol generating article 102 shown in FIG. However, the combustible heat source 103 is a non-continuous combustible heat source. The discontinuous heat source 103 comprises an annular body 115 of carbonaceous material having a passage 116 extending between the far end surface and the proximal end surface. The passage 116 forms part of an air flow path through the aerosol generating article 102 and allows air to be drawn from the proximal end of the aerosol generating article 102 through the combustible heat source 103 into the aerosol forming substrate 104. The layer of fiber-reinforced airgel 105 is spaced from the airflow passage through the aerosol-generating article 102 such that air drawn through the airflow passageway does not contact the fiber-reinforced airgel layer 105.

A non-combustible, substantially airtight first baffle 106 is located between the proximal end of the combustible heat source 103 and the distal end of the aerosol forming substrate 104 and is similar to the first baffle 6 described above with respect to FIG. However, unlike the first baffle 6 described above, the first baffle 106 includes an opening 120 aligned with the passage 116 to allow air to pass from the passage 116 into the aerosol-forming substrate 104.

A non-combustible, substantially airtight second baffle 117 is applied to the inner surface of the passage 116. The second baffle 117 isolates the passage of air through the passage 116 from the combustible heat source 103 and combustion products of the combustible heat source.

Since the combustible heat source 103 is a non-continuous heat source, the aerosol generating article 102 does not include air inlets located on the aerosol forming substrate 104. When the user puffs on the mouthpiece of the aerosol generating article 102, ambient air can be drawn into the aerosol generating article 102 through the passage 116 through the heat source 103. Air drawn into the aerosol generating article 102 can flow along the air flow path of the article 102 generating aerosol, through passage 116, through substrate 104, forming aerosol, conveying element, cooling element and separating element to the mouthpiece, and from the mouthpiece to the user for inhalation. The main direction of air flow through the aerosol generating article 102 is indicated by arrows.

It will be appreciated that, in some embodiments, other air inlets in the aerosol generating article may also be provided in addition to the passage for air flow through the combustible heat source.

The specific embodiments described above are intended to illustrate the invention. However, other embodiments may also be proposed without departing from the scope of the present invention as defined in the claims, and it should be understood that the above-described specific embodiments are not intended to be limiting.

Claims (30)

1. An aerosol generating article containing: aerosol forming substrate; combustible heat source; at least one layer of fiber-reinforced airgel surrounding at least a portion of the length of the combustible heat source; one or more air flow passages through which air can be drawn through the aerosol generating article for inhalation by a user; and one or more non-combustible, substantially airtight baffles between the combustible heat source and the aerosol-forming substrate. 2. An aerosol generating article according to claim 1, wherein said at least one layer of fiber-reinforced airgel is isolated from said one or more air flow passages such that, in use, air drawn through the aerosol generating article along one or more air flow passages, does not directly contact the at least one layer of fiber-reinforced airgel. 3. An aerosol-generating article according to any one of the preceding claims, wherein the combustible heat source, the aerosol-forming substrate and said at least one layer of fiber-reinforced aerosol are positioned such that the temperature of the aerosol-forming substrate does not exceed 375 ° C during burning time of a combustible heat source. 4. An aerosol generating article of any preceding claim, wherein the fiber-reinforced airgel contains less than about 80 percent by weight of the airgel. 5. An aerosol generating article of any preceding claim, wherein the fiber-reinforced airgel comprises at least about 20 percent by weight of fibrous material. 6. The aerosol generating article of claim 5, wherein the fiber-reinforced airgel comprises from about 20 percent by weight to about 70 percent by weight of fibrous material. 7. An aerosol generating article according to any one of the preceding claims, wherein the fiber-reinforced airgel comprises at least one of a ceramic fiber material and a glass fiber material. 8. An aerosol generating article according to any one of the preceding claims, wherein said at least one layer of fiber-reinforced airgel has a thickness of about 0.5 millimeters to about 5 millimeters. 9. An aerosol generating article according to any one of the preceding claims, wherein the non-combustible, substantially airtight baffle between the combustible heat source and the aerosol-forming substrate of the aerosol generating article comprises a first baffle that abuts one or both of the proximal end of the fuel a heat source and the distal end of the aerosol forming substrate. 10. An aerosol generating article according to any one of the preceding claims, wherein said one or more air flow passages comprise one or more air inlets located between the proximal end of the combustible heat source and the proximal end of the aerosol generating article, thus that this air can be drawn into said one or more air flow passages of the aerosol generating article through said one or more air inlets without passing through a combustible heat source. 11. An aerosol generating article according to any one of the preceding claims, wherein said one or more air flow passages comprise one or more air flow channels along the combustible heat source, and wherein a non-combustible, substantially airtight partition between the combustible heat source and said one or more channels for air flow further comprises a second partition between the combustible heat source and said one or more channels for air flow of the combustible heat source. 12. An aerosol generating article according to any of the preceding claims, wherein the aerosol generating article further comprises one or more additional layers surrounding at least the proximal portion of the combustible heat source and the distal portion of the substrate forming the aerosol, wherein said one or several additional layers contain at least one of: a heat transfer element for transferring heat from a combustible heat source to an aerosol-forming substrate, and a layer of cigarette paper. 13. An aerosol generating article of claim 12, wherein said at least one layer of fiber-reinforced airgel is a radially outer layer overlapping at least a portion of said one or more additional layers. 14. A method for forming an aerosol generating article according to claims 1-13, the method comprising: providing a combustible heat source with the ability to heat the substrate forming the aerosol; providing one or more air flow paths through which air can be drawn through the aerosol generating article for inhalation by the user, and isolating the combustible heat source from said one or more air flow passages such that, in use, air drawn through the aerosol generating article along the one or more air flow passages does not directly contact the combustible heat source; and surrounding at least part of the length of the combustible heat source with at least one layer of fiber-reinforced airgel. 15. The method of forming an aerosol generating article according to claim 14, wherein surrounding at least a portion of the length of the combustible heat source with at least one layer of fiber-reinforced airgel comprises: providing a strip of fiber-reinforced airgel having opposite ends; wrapping the strip around the combustible heat source, thereby surrounding the combustible heat source with at least one layer of fiber-reinforced airgel; overlapping opposite ends of the strip; and fastening the superimposed ends together to secure said at least one layer of fiber-reinforced airgel to a combustible heat source.

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