RU2815831C2 - Article for generating aerosol and method of producing same - Google Patents

Abstract

FIELD: smoking accessories.

SUBSTANCE: group of inventions relates to an article for generating an aerosol and a method for production thereof. Article for generating an aerosol comprises a combustible heat source having a longitudinal outer surface, an aerosol-forming substrate downstream of the combustible heat source and a retaining wrapper. Retaining wrapper comprises an upstream portion extending by at least 50 percent along the length of the combustible heat source on the longitudinal outer surface of the combustible heat source and comprising at least one opening, wherein at least one hole covers at least 30 percent of the longitudinal outer surface of the combustible heat source, and a downstream portion surrounding at least a portion of the aerosol-forming substrate.

EFFECT: sufficient amount of air of combustible heat source is provided to facilitate ignition and combustion of combustible heat source.

15 cl, 12 dwg

Description

The present invention relates to an aerosol generating article (aerosol generating article). More particularly, the present invention relates to an aerosol generating article comprising a combustible heat source; the aerosol-forming substrate is further downstream of the combustible heat source; and a retaining wrap configured to connect the combustible heat source to the aerosol-forming substrate. The present invention also relates to a method for producing an aerosol generating article.

A number of proposed alternative aerosol generating products are known from the prior art. One objective of such alternative aerosol generating products is to reduce the amount of certain smoke components of the type produced during combustion and pyrolytic degradation of tobacco in lit cigarettes. In one known type of aerosol generating article, the aerosol is generated by transferring heat from a combustible heat source to an aerosol-forming substrate located adjacent to the combustible heat source. During aerosol generation, by transferring heat from a combustible heat source, volatile compounds are released from the aerosol-generating substrate and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol. Such products are sometimes known as heated aerosol generating products.

In heated aerosol-generating articles (aerosol-generating articles) that contain a combustible heat source and an aerosol-forming substrate, the combustible heat source must be securely attached to the rest of the aerosol-generating article. The combustible heat source must remain securely attached to the aerosol-generating substrate from the time of manufacture, during transportation, use, and sometimes until disposal of the aerosol-generating product.

Combustible heat sources of the type used in aerosol-generating products may be damaged before or during use. For example, certain combustible heat sources may be fragile. Fragile combustible heat sources can easily become damaged, such as cracking or splintering, before or during use. Some combustible heat sources contain carbon. Combustible heat sources containing carbon can be brittle, which can make them especially prone to damage. In addition, some flammable heat sources are produced using powder processing technologies, and these technologies may produce combustible heat sources that are prone to damage. Damage to combustible heat sources during use may result in the combustible heat source material breaking off. Because of this, less fuel may be burned when using an aerosol-generating product. This may affect the amount of heat transferred from the combustible heat source to the aerosol-forming substrate, and therefore may affect the release of volatile compounds from the aerosol-forming substrate. In addition, breaking off the combustible heat source material may create unacceptable dirt and may affect the appearance of the combustible heat source.

When applied, a combustible heat source ignites and burns to produce heat, which is transferred to the substrate, forming an aerosol. To enable ignition and efficient combustion of a combustible heat source, there must be a good supply of air to the combustible heat source.

WO 2017/114683 A1 describes an aerosol generating article comprising a combustible heat source, an aerosol generating substrate located downstream of the combustible heat source and a wrapper surrounding at least a rear portion of the combustible heat source and at least a forward portion of the aerosol generating substrate. substrate. In the area of the wrapper covering the combustible heat source, a plurality of weakened areas are provided. The wrapper is designed to be tearable when used at a plurality of weakened areas to form a ventilation zone containing a plurality of holes extending through the wrapper. The weakened areas may be positioned such that the wrapper breaks at the weakened areas under pressure generated by flammable gases from the combustible heat source during use.

It may be desirable to provide an aerosol generating article with improved retention of a combustible heat source. It may also be desirable to provide an aerosol generating article that prevents loss of material from the combustible heat source due to damage to the combustible heat source. It may also be desirable to provide an aerosol generating article that allows sufficient air to enter the combustible heat source to effectively ignite and burn the combustible heat source.

The present invention provides an aerosol generating article comprising a combustible heat source having a longitudinal outer surface; the aerosol-forming substrate is further downstream of the combustible heat source; and a retaining wrap.

The containment wrap may include an upstream portion that extends along the combustible heat source relative to the longitudinal outer surface of the combustible heat source to at least about 50 percent of its length. This may advantageously improve retention of the combustible heat source relative to the aerosol-forming substrate.

An upstream portion of the containment wrap may include at least one opening. This may advantageously allow sufficient air to reach the combustible heat source to facilitate ignition and combustion of the combustible heat source. Providing at least one opening allows the containment wrap to extend further toward the upstream end of the combustible heat source. This may advantageously improve retention of the combustible heat source relative to the aerosol-forming substrate while still allowing sufficient air to reach the combustible heat source to promote easy and rapid ignition through a conventional yellow flame cigarette lighter. A sufficient amount of air may also be able to reach the combustible heat source to promote uniform combustion of the combustible heat source.

The at least one opening may cover at least about 30 percent of the longitudinal outer surface of the combustible heat source. This may advantageously ensure that the at least one opening is large enough to allow sufficient air to reach the combustible heat source to facilitate ignition and combustion of the combustible heat source.

The containment wrap may include a downstream portion surrounding at least a portion of the aerosol-forming substrate. This may advantageously further improve retention of the combustible heat source relative to the aerosol-forming substrate. In addition, if the containment wrap contains a thermally conductive material, its presence may facilitate the transfer of heat from the combustible heat source to the aerosol-forming substrate.

In one preferred embodiment, the present invention provides an aerosol generating article comprising a combustible heat source having a longitudinal outer surface; the aerosol-forming substrate is further downstream of the combustible heat source; and a retaining wrap. The containment wrap contains an upstream portion whose extent along the combustible heat source relative to the longitudinal outer surface of the combustible heat source is at least about 50 percent of its length. The upstream portion of the containment wrapper contains at least one opening. The at least one opening covers at least about 30 percent of the longitudinal outer surface of the combustible heat source. The containment wrap further includes a downstream portion surrounding at least a portion of the aerosol-forming substrate.

The retaining wrap is configured to connect the combustible heat source to the aerosol-forming substrate. Providing a containment wrap having an upstream portion around the combustible heat source and a downstream portion around the aerosol-forming substrate preferably improves retention of the combustible heat source relative to the aerosol-forming substrate.

Providing an upstream portion of the containment wrap that extends along the combustible heat source relative to the longitudinal outer surface of the combustible heat source is at least about 50 percent of its length may advantageously allow the containment wrap to retain the combustible heat source along a large portion of its length. This may advantageously improve retention of the combustible heat source relative to the aerosol-forming substrate. Providing this may also help to retain most of any material generated when the combustible heat source is damaged. This may advantageously prevent loss of material generated when the combustible heat source is damaged. The present inventors have discovered that greater coverage of the combustible heat source by the containment wrap can improve the retention of material generated when the combustible heat source is damaged.

The extent of the upstream portion of the containment wrap along the combustible heat source relative to the longitudinal outer surface of the combustible heat source may be at least about 60 percent, at least about 70 percent, at least about 80 percent, at least about 90 percent, or at least approximately 95 percent of its length.

In other words, the extent of the upstream portion of the containment wrap along the combustible heat source relative to the longitudinal outer surface of the combustible heat source may be from about 50 percent to about 100 percent, from about 60 percent to about 100 percent, from about 70 percent to about 100 percent. percent, from about 80 percent to about 100 percent, from about 90 percent to about 100 percent, or from about 95 percent to about 100 percent of its length.

The upstream portion of the containment wrap may extend beyond the upstream end of the combustible heat source. It should be understood that the expression "extends beyond" means that the containment wrap extends to the upstream end of the combustible heat source. For example, the upstream portion of the containment wrap may extend approximately 1 millimeter to the upstream end of the combustible heat source.

The upstream end of the containment wrap may be located some distance from the upstream end of the combustible heat source.

Providing an upstream end of the containment wrap located some distance from the upstream end of the combustible heat source may advantageously facilitate ignition of the combustible heat source because it leaves a portion of the upstream end of the combustible heat source open for ignition by external heat source.

The length of the upstream portion of the containment wrap along the combustible heat source relative to the longitudinal outer surface of the combustible heat source may be no more than about 95 percent, about 90 percent, about 80 percent, about 70 percent, or about 60 percent of its length. Providing this may advantageously improve the retention of the combustible heat source by the containment wrap. Providing this may also advantageously prevent loss of material from the combustible heat source due to possible damage to the combustible heat source.

The length of the upstream portion of the containment wrap along the combustible heat source relative to the longitudinal outer surface of the combustible heat source may be from about 50 percent to about 95 percent, from about 60 percent to about 90 percent, or from about 70 percent to about 80 percent of its length .

Providing an upstream portion of the containment wrap containing at least one opening covering at least about 30 percent of the longitudinal outer surface of the combustible heat source may allow sufficient air to reach the combustible heat source to facilitate ignition and combustion of the combustible heat source. Providing an upstream portion of the containment wrap containing at least one opening covering at least about 30 percent of the longitudinal outer surface of the combustible heat source may allow the combustible heat source to be ignited by heat, such as from a flame, passing through the at least one a hole in the upstream portion of the containment wrapper to the combustible heat source. This may advantageously allow easy and rapid ignition by a conventional yellow flame cigarette lighter and more complete combustion of the combustible heat source compared to examples that do not provide at least one opening in the retaining wrap and therefore only allow ignition on the upstream end of the combustible heat source behind the upstream end of the containment wrap.

The upstream portion of the containment wrap contains at least one opening covering at least about 30 percent of the longitudinal outer surface of the combustible heat source. In other words, at least about 30 percent of the longitudinal outer surface of the combustible heat source will not be covered by the containment wrap and will instead be exposed in the area of the at least one opening. The at least one opening is configured such that the portion of the longitudinal outer surface of the combustible heat source that is open in the area of the at least one opening corresponds to at least approximately 30 percent of the entire longitudinal outer surface of the combustible heat source. As will be understood below, the term "hole" should be understood to refer both to openings in the containment wrap that are surrounded on all sides by the containment wrap and to openings that extend the entire distance to the upstream end of the containment wrap. such that the upstream edge of the retaining wrap defines a portion of the at least one opening.

The at least one opening in the upstream portion of the containment wrap may cover at least about 40 percent, at least about 50 percent, or at least about 60 percent of the longitudinal outer surface of the combustible heat source.

The at least one opening in the upstream portion of the containment wrap may cover less than 100 percent of the longitudinal outer surface of the combustible heat source. For example, at least one opening in the upstream portion of the containment wrap may cover less than 90 percent, less than 80 percent, or less than 70 percent of the longitudinal outer surface of the combustible heat source.

The at least one opening in the upstream portion of the containment wrap may cover from about 40 percent to about 90 percent, from about 50 percent to about 80 percent, or from about 60 percent to about 70 percent of the longitudinal outer surface of the combustible heat source. Preferably, at least one opening in the upstream portion of the containment wrap may cover approximately 65 percent of the longitudinal outer surface of the combustible heat source.

More preferably, if at least one hole in the upstream portion of the containment wrap covers approximately 65 percent of the longitudinal outer surface of the combustible heat source, the upstream portion of the containment wrap extends to the upstream end of the combustible heat source.

Providing a downstream portion of the containment wrap surrounding at least a portion of the aerosol-forming substrate can further improve containment of the combustible heat source relative to the aerosol-forming substrate because a greater surface area of the containment wrap is in contact with the outer surface of the aerosol-forming substrate. In addition, as further discussed below, providing a downstream portion of the containment wrap surrounding at least a portion of the aerosol-forming substrate may improve heat transfer between the combustible heat source and the aerosol-forming substrate if the containment wrap contains a thermally conductive material. Providing a downstream portion of the containment wrap surrounding at least a portion of the aerosol-forming substrate may advantageously provide uniform heat transfer from the combustible heat source to the aerosol-forming substrate if the containment wrap contains a thermally conductive material.

The downstream portion of the containment wrap may surround the aerosol-forming substrate by an extent of at least about 60 percent, at least about 70 percent, at least about 80 percent, at least about 90 percent, or at least about 90 percent. approximately 95 percent of its length. The downstream portion of the containment wrap may surround the entire length of the aerosol-forming substrate.

The downstream portion of the containment wrap may extend beyond the downstream end of the aerosol-forming substrate. In this case, the downstream portion of the containment wrap can be used to securely attach the combustible heat source and aerosol-generating substrate to other components of the aerosol-generating article. Other possible components of an aerosol generating product are discussed below. The downstream portion of the containment wrap may extend to the downstream end of the combustible heat source so that it wraps all components of the aerosol generating article between the downstream end of the combustible heat source and the downstream end of the article. , generating aerosol.

The present inventors have discovered that it may be desirable to securely attach a combustible heat source to an aerosol-forming substrate. The present inventors have also discovered that it may be desirable to eliminate loss of combustible heat source material due to damage to the combustible heat source. The inventors have discovered that these problems can be solved by providing a containment wrap having an upstream portion that extends along the combustible heat source relative to the longitudinal outer surface of the combustible heat source to at least about 50 percent of its length and that surrounds at least part of the substrate forming the aerosol; and a downstream portion surrounding at least a portion of the aerosol-forming substrate. The holding wrap can securely attach the combustible heat source to the aerosol-forming substrate. As will be understood below, the inventors have discovered that to ensure containment of a combustible heat source or containment of material generated when a combustible heat source is damaged, the extent of the containment wrap along the combustible heat source must be at least about 50 percent of its length. However, the present inventors have discovered that extending the containment wrap so long along the length of the combustible heat source may result in an unfavorable reduction in the amount of air that can reach the combustible heat source. This may make it impossible for the combustible heat source to ignite and burn evenly or completely. The present inventors have discovered that providing at least one opening in the upstream portion of the containment wrap preferably allows sufficient air to reach the combustible heat source while at the same time allowing the containment wrap to extend along a significant length of the combustible heat source to provide thereby containing the combustible heat source or containing material generated when the combustible heat source is damaged. In particular, the present inventors have found that to allow sufficient air to reach the combustible heat source, at least one opening must cover at least about 30 percent of the longitudinal surface of the combustible heat source.

As discussed in more detail below, the at least one opening provided in the retaining wrap may be of any shape or size. Thanks to the at least one opening provided in the containment wrapper, aerosol generating articles are possible in which the containment wrapper does not surround a combustible heat source. This may be the case when the portion of the retaining wrap extending along the outer surface of the combustible heat source is made in the form of several strips.

The combustible heat source has a longitudinal outer surface.

In the context of this invention document, the words “longitudinal” and “axial” are used to describe the direction between the opposing upstream and downstream ends of an aerosol generating article or component of an aerosol generating article. The "longitudinal outer surface" is therefore the outer surface of the aerosol generating article component that extends between the opposing upstream and downstream ends of the aerosol generating article component.

In the context of this invention document, the words "surround" and "surrounding" refer to the first element extending around the entire circumference of the second element. For example, in the present invention, the downstream portion of the containment wrap surrounds at least a portion of the aerosol-forming substrate. This means that at one or more points along the longitudinal length of the aerosol-forming substrate, a downstream portion of the containment wrap extends around the entire circumference of the aerosol-forming substrate.

In the context of this invention document, the words "upstream" and "forward" and "downstream" and "rear" are used to describe the relative positions of components, or portions of components, of an aerosol generating article with respect to the direction in which air currents pass through the aerosol-generating product during use. The aerosol generating articles of the invention comprise a proximal end through which, upon use, the aerosol exits the article for delivery to the user. The proximal end of the aerosol generating article may also be referred to as the mouth end or the downstream end. When used, the user takes a puff through the mouthpiece end of the aerosol-generating product. The mouthpiece end is located downstream of the distal end. A combustible heat source is located at or near the distal end. The distal end of the aerosol generating article may also be referred to as the upstream end. Components, or portions of components, of a smoking article may be described as being upstream or downstream of each other based on their relative positions between the proximal end of the smoking article and the distal end of the smoking article. The front side of a component, or portion of a component, of an aerosol generating article is the portion at the end closest to the upstream end of the aerosol generating article. The back side of a component, or portion of a component, of an aerosol generating article is the portion at the end closest to the downstream end of the aerosol generating article. The combustible heat source rear portion is the combustible heat source portion at the downstream end of the combustible heat source. The forward portion of the aerosol-forming substrate is the portion of the aerosol-forming substrate at the upstream end of the aerosol-forming substrate.

The upstream portion of the containment wrap may extend to the upstream end of the combustible heat source.

This may advantageously further improve retention of the combustible heat source relative to the aerosol-forming substrate. Providing this may also help to retain most of any material generated when the combustible heat source is damaged. The upstream end of the combustible heat source, and in particular the upstream portion of the edge of the combustible heat source, may be particularly susceptible to damage due to splintering. Providing a containment wrap up to the upstream end of the combustible heat source may advantageously improve containment of material generated when the combustible heat source is damaged at the upstream end of the combustible heat source.

The combustible heat source may comprise an upstream flat end surface at the upstream end of the combustible heat source.

If the combustible heat source includes an upstream flat end surface at the upstream end of the combustible heat source, the containment wrap may extend over at least a portion of the flat end surface of the combustible heat source.

This may advantageously further improve retention of the combustible heat source relative to the aerosol-forming substrate. This may advantageously further improve the retention of material generated when a combustible heat source is damaged

If the combustible heat source includes an upstream flat end surface at the upstream end of the combustible heat source, the containment wrap may not extend over at least a portion of the flat end surface of the combustible heat source. In other words, the upstream flat end surface of the combustible heat source can be exposed.

This may advantageously improve ignition and combustion of the combustible heat source by allowing air to reach the combustible heat source.

If the upstream portion of the containment wrap extends to the upstream end of the combustible heat source, the at least one opening may preferably cover at least about 50 percent of the longitudinal outer surface of the combustible heat source. This may advantageously expose a significant area of the combustible heat source to facilitate easy and rapid ignition through a traditional yellow flame cigarette lighter. A sufficient amount of air may also be able to reach the combustible heat source to promote uniform combustion of the combustible heat source.

The at least one opening in the upstream portion of the containment wrap may have a total area of at least about 45 square millimeters. In other words, at least approximately 45 millimeters square of the longitudinal outer surface of the combustible heat source will not be covered by the containment wrap and will instead be exposed in the region of the at least one opening.

This may advantageously allow access of sufficient air to the combustible heat source for efficient ignition and combustion of the combustible heat source. Providing an upstream portion of the containment wrap containing at least one opening with a total area of at least about 45 square millimeters may enable the combustible heat source to be ignited by heat, such as from a flame, passing through the at least one opening in the upstream along the flow of a portion of the retaining wrap towards the combustible heat source. This may allow easy and rapid ignition by a traditional yellow flame cigarette lighter and more complete combustion of the combustible heat source compared to examples that do not provide at least one hole in the retaining wrap and therefore only allow ignition at a previously located the downstream end of the combustible heat source behind the upstream end of the retaining wrapper. Providing an upstream portion of the containment wrap containing at least one opening with a total area of at least about 45 square millimeters may also allow the containment wrap to extend further toward the upstream end of the combustible heat source. This may advantageously improve retention of the combustible heat source relative to the aerosol-forming substrate while still allowing sufficient air to reach the combustible heat source to promote easy and rapid ignition by a conventional yellow flame cigarette lighter, as well as uniform combustion of the combustible heat source.

The at least one opening of the retaining wrap may have a total area of at least about 60 square millimeters, at least about 80 square millimeters, at least about 100 square millimeters, or at least about 120 square millimeters.

The at least one opening of the retaining wrap may have a total area of less than about 180 square millimeters, less than about 140 square millimeters, less than about 120 square millimeters.

The at least one opening of the retaining wrap may have a total area of from about 60 square millimeters to about 180 square millimeters, or from about 80 square millimeters to about 140 square millimeters. Preferably, the at least one opening of the retaining wrap may have a total area of from about 90 square millimeters to about 110 square millimeters. More preferably, the at least one opening of the retaining wrap may have a total area of approximately 96 square millimeters.

The at least one opening in the upstream portion of the containment wrap may comprise an opening having an area of at least about 45 square millimeters, at least about 48 square millimeters, or at least about 55 square millimeters.

This may advantageously ensure that the at least one opening comprises an opening large enough to allow sufficient air to reach the combustible heat source to facilitate ignition and combustion of the combustible heat source.

Each of the at least one opening in the upstream portion of the containment wrap may have an area of at least about 45 square millimeters, at least about 48 square millimeters, or at least about 55 square millimeters.

The at least one opening in the upstream portion of the containment wrap may comprise a rectangular opening.

The at least one opening in the upstream portion of the containment wrap may include an opening with a constant width along the entire length of the opening.

The opening may have a width of from about 4 millimeters to about 16 millimeters, from about 6 millimeters to about 14 millimeters, or from about 8 millimeters to about 12 millimeters. Preferably the hole has a width of approximately 10 millimeters.

The hole may have a length of from about 3 millimeters to 9 millimeters, or from about 4.5 millimeters to about 6 millimeters. The hole may be approximately 4.5 millimeters in length. The hole may be approximately 5.5 millimeters in length. The hole may be approximately 6 millimeters in length.

The at least one opening in the upstream portion of the containment wrap may include an opening having a narrow portion and a wider portion. The narrow part may have a rectangular shape. The wider part may have a rectangular shape.

The narrow portion of the opening may have a width of from about 0.5 millimeters to about 3.5 millimeters, from about 1 millimeter to about 3 millimeters, or from about 1.5 millimeters to about 2.5 millimeters. Preferably, the narrow portion of the opening is approximately 2 millimeters wide.

The narrow portion of the opening may have a length of from about 0.5 millimeters to about 5 millimeters, from about 1 millimeter to about 5 millimeters, or from about 1 millimeter to about 3 millimeters. Preferably, the narrow portion of the opening is approximately 1.5 millimeters in length.

The wider portion of the opening may have a width of from about 4 millimeters to about 16 millimeters, from about 6 millimeters to about 14 millimeters, or from about 8 millimeters to about 12 millimeters. Preferably, the wider portion of the opening is approximately 10 millimeters wide.

The wider portion of the opening may have a length of from about 3 millimeters to about 7 millimeters, from about 4 millimeters to about 6 millimeters, or from about 4.5 millimeters to about 5.5 millimeters. The wider part of the hole may be approximately 4.5 millimeters in length. The wider part of the hole may be approximately 5.5 millimeters in length.

The narrow portion of the opening may be located downstream of the wider portion of the opening. Alternatively, the narrow portion of the opening may be located upstream of the wider portion of the opening.

As used herein regarding the invention, the term “length” refers to the size of an element, such as an orifice or combustible heat source, in the longitudinal direction of the aerosol generating article, from the upstream end of the element to the downstream end of the element.

In the context of this invention document, the term "width" refers to the size of a feature, such as an opening, in a direction perpendicular to the longitudinal direction of the aerosol generating article. In particular, it will be understood that if the aerosol generating article or components of the aerosol generating article have curved surfaces, the "width" of the elements may follow a curved line along the contours of the surface of the aerosol generating article.

The retaining wrap may be adhered to the surface of the combustible heat source.

This may advantageously improve retention of the combustible heat source relative to the aerosol-forming substrate.

The upstream portion of the containment wrap may be adhered to the surface of the combustible heat source using adhesive. The adhesive may be any suitable adhesive. Preferably, the adhesive is a heat-resistant adhesive. Preferably stable at temperatures reached by combustion of a combustible heat source. For example, the adhesive may be a silicate adhesive.

The adhesive may be applied between the combustible heat source and the upstream portion of the containment wrap on only a portion of the combustible heat source.

The adhesive may be applied to only a portion of the upstream portion of the retaining wrap.

The upstream portion of the containment wrapper may have any shape. For example, the upstream portion of the containment wrap may be a longitudinal line, a transverse line, an oval, a spiral, a square, or a dot. Several pieces of an upstream portion of the containment wrap may be provided. The multiple portions of the upstream portion of the containment wrap may comprise multiple longitudinal lines, multiple transverse lines, or multiple points.

The adhesive may be applied to the entire upstream portion of the retaining wrap.

Alternatively, the retaining wrap may not be adhered to the surface of the combustible heat source.

This may advantageously simplify the manufacture of the aerosol generating article. If the retaining wrap is not adhered to the surface of the combustible heat source, then tightly fitting the combustible heat source into the retaining wrap may be sufficient to retain the combustible heat source.

The downstream portion of the containment wrap may be adhered to the surface of the aerosol-forming substrate.

The retaining wrap may comprise any suitable material. Preferably, the retaining wrap contains a material that is heat resistant. Preferably, the containment wrap contains a thermally conductive material.

The retaining wrap may comprise metal foil. For example, the retaining wrap may comprise a foil derived from aluminum (aluminum foil).

Preferably, the use of metal foil can provide reliable retention of the combustible heat source against the aerosol-forming substrate, even when the combustible heat source is ignited. The use of metal foil can provide efficient heat transfer between the combustible heat source and the aerosol-forming substrate. This may advantageously improve the generation of aerosol from the aerosol-forming substrate.

The metal foil may have a thickness of at least about 5 micrometers. For example, the metal foil may have a thickness of at least about 10 micrometers or at least about 15 micrometers. The metal foil may have a thickness of no more than about 60 micrometers. For example, the metal foil may have a thickness of no more than about 40 micrometers, no more than about 35 micrometers, no more than about 30 micrometers, or no more than about 25 micrometers.

The metal foil may have a thickness of from about 5 micrometers to about 40 micrometers, from about 10 micrometers to about 35 micrometers, or from about 15 micrometers to about 25 micrometers. Preferably, the metal foil may have a thickness of approximately 20 micrometers.

Preferably, the metal foil is provided in at least some portion of both the upstream portion of the containment wrapper and the downstream portion of the containment wrapper. This may advantageously improve heat transfer between the combustible heat source and the aerosol-forming substrate.

In some embodiments, both the upstream portion of the containment wrap and the downstream portion of the containment wrap contain metal foil, and the metal foil surrounds at least a portion of the aerosol-forming substrate.

In addition to the metal foil, the retention wrap may contain other materials. In this case, the metal foil may be positioned radially closer or radially further away from the combustible heat source than other materials. Preferably, the metal foil is positioned closer to the surface of the combustible heat source than any of the other containment wrap materials. This may advantageously provide the most efficient heat transfer between the combustible heat source and the aerosol-forming substrate.

The retaining wrap may contain paper.

Preferably, the use of paper may provide the appearance and texture of the outer surface of the aerosol generating article as that of traditional cigarettes. In addition, the use of paper may simplify the manufacture of the aerosol generating article.

The paper may have a thickness of at least about 20 micrometers. For example, the paper may have a thickness of at least about 30 micrometers or at least about 40 micrometers. The paper may have a thickness of no more than about 100 micrometers. For example, the paper may have a thickness of no more than about 80 micrometers, 70 micrometers, or no more than 60 micrometers.

The paper may have a thickness of from about 20 micrometers to about 100 micrometers, from about 30 micrometers to about 70 micrometers, or from about 40 micrometers to about 60 micrometers. Preferably the paper has a thickness of approximately 50 micrometers.

In addition to paper, the retention wrap may contain other materials. For example, the retaining wrap may comprise a combination of paper and metal foil. In this case, the metal foil can be attached to the paper using glue. The adhesive may be sprayed or otherwise applied to the surface of the paper before applying the metal foil. Alternatively or in addition, adhesive may be sprayed or otherwise applied to the surface of the metal foil before applying the paper. As stated above. If the containment wrapper contains both paper and metal foil, it is preferred that the metal foil be radially closer to the combustible heat source than the paper.

If the containment wrap contains a combination of paper and metal foil, then the paper and metal foil can cover the same area of the combustible heat source.

Alternatively, metal foil may cover more of the longitudinal surface area of the combustible heat source than paper. In this case, preferably the paper and metal foil together extend along the downstream portion of the combustible heat source, with only the metal foil extending further along the upstream portion of the combustible heat source.

Alternatively, the paper may cover more of the longitudinal surface area of the combustible surface of the combustible heat source than metal foil. In this case, preferably the paper and metal foil together extend along the downstream portion of the combustible heat source, with only the paper extending further along the upstream portion of the combustible heat source.

For example, at least about 10 percent of the length of the upstream portion of the containment wrap may contain both paper and metal foil. Preferably, at least about 25 percent, at least about 50 percent, at least about 75 percent, or at least about 90 percent of the length of the upstream portion of the containment wrap may comprise both paper and metal foil. The remaining percentages of the length of the upstream portion of the containment wrapper may comprise only one of paper or metal foil.

The upstream portion of the containment wrap may contain both paper and metal foil, while the downstream portion of the containment wrap may contain only paper.

The paper may comprise at least one of paper combined with a layer of metal or metallized paper.

The paper combined with a metal layer may comprise a layer of paper with a layer of metal deposited on the surface. The metal layer can be applied to the paper using glue.

Metallized paper may comprise a layer of paper with a layer of metal deposited on the surface. The metal layer can be applied, for example, by deposition. The metal layer may contain aluminum.

If the paper comprises paper combined with a layer of metal, or metallized paper, the metal component of the paper is different from the metal foil described above, which may also form part of the retaining wrap.

Preferably, the paper combined with a metal layer or metallized paper may exhibit higher heat resistance compared to paper that is not combined with a metal layer or non-metalized paper.

The containment wrap may have a maximum thickness of no more than about 190 micrometers. If the containment wrap contains more than one component, this means that the total thickness of all of the components of the containment wrap is no more than about 190 micrometers. For example, the retention wrap may have a maximum thickness of no more than about 160 micrometers, no more than about 150 micrometers, no more than about 120 micrometers, no more than about 100 micrometers, or no more than about 80 micrometers.

The containment wrap may have a maximum thickness of at least about 40 micrometers. For example, the retention wrap may have a maximum thickness of at least about 50 micrometers or at least about 60 micrometers.

The retaining wrap may have a thickness of approximately 70 micrometers.

The at least one opening in the containment wrapper may comprise an opening surrounded on all sides by the containment wrapper. In this case, at least one opening in the retaining wrap is limited on all sides by the retaining wrap. In other words, the opening surrounded on all sides by the retaining wrap may be an opening extending through the material from which the retaining wrap is made.

The hole can have any shape. For example, the hole may have a shape including, but not limited to, circle, square, rectangle, diamond, spiral, and hexagon. The shape of the hole may create visible marks on the outer surface of the wrapper.

In the context of this invention document, the term “visible indicia” refers to a discrete element that provides an aesthetically pleasing appearance or conveys certain information. Marks may be in the form of text, images, letters, words, logos, or a combination thereof. The marks may contain the manufacturer's trademark or logo to enable the consumer to identify the type or origin of the aerosol-generating product. The signs may provide information to the user, such as informing the user that the aerosol-generating product is ready for use. The light emanating from the combustible heat source may be visible through the hole during use. This can increase the visibility of the signs. In addition, a change in color of the combustible heat source (eg, indicating that the combustible heat source has burned out) may be visible through the hole.

Providing at least one opening in the containment wrap, comprising the opening surrounded on all sides by the containment wrap, allows the upstream end of the containment wrap to completely surround a portion of the combustible heat source to form a continuous ring of the containment wrap. This may advantageously improve retention of the combustible heat source by allowing the containment wrap to tightly hold the combustible heat source.

The upstream end of the at least one opening may be located at a distance of at least about 1 millimeter from the upstream end of the containment wrap.

This may advantageously allow better containment of the combustible heat source relative to the aerosol-forming substrate by a continuous ring of the containment wrap at the upstream end of the containment wrap.

The upstream edge of the at least one opening may be located at a distance of at least about 1.5 millimeters, at least about 2 millimeters, at least about 2.5 millimeters, or at least about 3 millimeters from the upstream edge of the at least one opening. earlier in the flow of the end of the retaining wrap.

The at least one opening may extend to an upstream end of the containment wrap without the at least one opening in the containment wrap being surrounded on all sides by the containment wrap. In this case, the at least one opening in the retaining wrap is limited on at least one side by the upstream end of the retaining wrap. In this case, the containment wrap can be configured as a plurality of strips extending from the downstream end of the combustible heat source towards the upstream end of the combustible heat source.

Providing this allows for a continuous supply of air from the upstream end of the combustible heat source up to the downstream end of the at least one opening. This may advantageously provide improved combustion of the combustible heat source.

Preferably, the downstream end of the at least one opening does not extend to the downstream end of the combustible heat source. The authors have found that in some cases, holes that extend to the downstream end of the combustible heat source may be less effective in heating the aerosol-forming substrate. This may be because in these embodiments, where the containment wrap contains thermally conductive material, there is less thermally conductive material at the downstream end of the combustible heat source to transfer heat from the combustible heat source to the aerosol-forming substrate. Preferably, the downstream end of the at least one opening is located at a distance of no closer than 1 millimeter or at a distance of no closer than 2 millimeters from the downstream end of the combustible heat source. In some particularly preferred embodiments, the downstream end of the at least one opening is located at a distance of approximately 3 millimeters from the downstream end of the combustible heat source.

Preferably, the upstream portion of the containment wrapper extends to the upstream end of the combustible heat source, the containment wrapper comprises both metal foil and paper combined with a layer of metal or metallized paper, and at least one opening covers from about 50 percent to approximately 90 percent of the longitudinal outer surface of the combustible heat source.

The at least one hole may contain any number of holes. For example, the at least one hole may contain 1, 2, 3, 4, 5, 10 or 20 holes. The at least one opening may comprise a combination of one or more openings that include an opening surrounded on all sides by a containment wrap and one or more openings that extend to an upstream end of the containment wrap.

Preferably, at least one hole consists of 2 holes. That is, the at least one hole consists of a first hole and a second hole. Preferably, the first hole and the second hole are evenly distributed across the combustible heat source.

Providing the first and second openings uniformly distributed around the combustible heat source may allow air to uniformly access the combustible heat source. This may advantageously allow uniform combustion of the combustible heat source, which in turn may provide more uniform, efficient and predictable heating of the aerosol-forming substrate.

Preferably, the second hole is approximately the same size and approximately the same shape as the first hole. This may advantageously simplify the manufacture of the aerosol generating article, while also allowing more uniform access of air to the combustible heat source. This may advantageously further enable more uniform combustion of the combustible heat source, which in turn may provide more uniform, efficient and predictable heating of the aerosol-forming substrate.

The present invention also provides a method for producing an aerosol generating article. The method includes providing a combustible heat source and an aerosol-forming substrate; providing a portion of the wrapper material; and making at least one hole in the portion of the wrapper material to form a retaining wrapper. The method further includes applying a containment wrap to the combustible heat source and the aerosol-forming substrate. The containment wrap may be so applied to the combustible heat source and the aerosol-forming substrate that the extent of the upstream portion of the containment wrap along the combustible heat source relative to the longitudinal outer surface of the combustible heat source is at least about 50 percent of its length. The containment wrap may be applied to the combustible heat source and the aerosol-forming substrate such that the upstream portion of the containment wrap contains at least one opening and the downstream portion of the containment wrap surrounds at least a portion of the aerosol-forming substrate. .

Preferably, a method for producing an aerosol generating article is provided. The method includes providing a combustible heat source and an aerosol-forming substrate; providing a portion of the wrapper material; and making at least one hole in the portion of the wrapper material to form a retaining wrapper. The method further includes applying a containment wrap to the combustible heat source and the aerosol-forming substrate such that the length of the upstream portion of the containment wrap along the combustible heat source relative to the longitudinal outer surface of the combustible heat source is at least about 50 percent of its length, wherein the upstream portion of the containment wrapper has at least one opening, and the downstream portion of the containment wrapper surrounds at least a portion of the aerosol-forming substrate.

Providing that at least one hole is made in a portion of the wrap material to form a containment wrap before applying the containment wrap eliminates the need to make at least one hole in the wrap material after applying the containment wrap to the combustible heat source and the aerosol-forming substrate. This may advantageously simplify manufacturing by allowing the opening to be made in the flow even when the wrapper material is flat rather than when it is wrapped around the combustible heat source and the aerosol-forming substrate. In addition, this may advantageously provide a manufacturing method that has less risk of damaging the combustible heat source during the making of the at least one hole in the containment wrap. This, in turn, can result in lower defect rates for aerosol-generating products.

The containment wrap may be applied to the combustible heat source such that at least one opening covers at least about 30 percent of the longitudinal outer surface of the combustible heat source.

The method may further include the steps of adding other components to the aerosol generating article. For example, the method may include adding one or more of an aerosol cooling element, a transfer element, and a filter-containing mouthpiece to the aerosol generating article. If the containment wrap extends to the downstream end of the aerosol generating article, then the containment wrap can be applied to all of the additional components. Alternatively, after applying the containment wrap to the combustible heat source and aerosol-generating substrate, an outer wrap may be applied to connect the combustible heat source and aerosol-generating substrate to other components of the aerosol-generating article.

The step of providing a portion of the retaining wrapper may include: providing a portion of paper combined with a layer of metal or metallized paper; providing a metal foil part; and attaching the metal foil portion to the paper portion.

The metal foil piece can be attached to the paper piece using glue. The method may include spraying or layering adhesive onto the paper portion before applying the metal foil portion to the adhesive. The metal foil part may be a piece of aluminum.

The step of providing at least one hole in the portion of the wrapper material may include providing one hole extending through both the metal-combined paper or metallized paper portion and the metal foil portion.

The step of making at least one hole in a portion of the wrapper material may be performed using one or more of a die, a laser, a utility knife, or a combination of knives as needed to achieve the desired shape.

The aerosol generating articles of the present invention comprise a combustible heat source for heating the aerosol generating substrate. The combustible heat source is preferably a solid heat source and may comprise any suitable combustible material, including, but not limited to, carbon and carbon-based materials containing aluminum, magnesium, one or more carbides, one or more nitrides, and combinations thereof. Solid combustible heat sources for heated smoking articles and methods for producing such heat sources are known in the art and are described, for example, in US-A-5040552 and US-A-5595577. Typically, known solid combustible heat sources for heated smoking articles are carbon-based, that is, they contain carbon as the main combustible material.

The combustible heat source may be a combustible carbon heat source.

The combustible heat source is preferably a continuous combustible heat source.

In the context of this invention document, the word “solid” describes a heat source that does not contain any air flow passages extending from the front end surface to the rear end surface of the combustible heat source. In the context of this invention document, the word "solid" is also used to describe a combustible heat source comprising one or more channels extending from a front end surface of the combustible heat source to a rear end surface of the combustible heat source, wherein between the rear end surface of the combustible heat source and the aerosol-forming substrate is provided with a combustible, substantially airtight barrier, wherein the barrier prevents air from being drawn along the length of the combustible heat source through one or more passages.

The presence of one or more closed air passages increases the surface area of the continuous combustible heat source exposed to oxygen from the air and may advantageously promote ignition and uniform combustion of the continuous combustible heat source.

Aerosol generating articles of the present invention containing continuous combustible heat sources include one or more air inlets located downstream of the rear end surface of the combustible heat source to draw air into one or more air flow passages through the article , generating an aerosol. Aerosol generating articles of the present invention containing non-continuous combustible heat sources may also include one or more air inlets located downstream of the rear end surface of the combustible heat source to draw air into the one or more air flow passages. through an aerosol-generating product. If the aerosol generating article includes one or more air inlets downstream of the rear end surface of the combustible heat source, then one or more air inlets may be located in the downstream portion of the containment wrap. Alternatively, one or more downstream air inlets relative to the rear end surface of the combustible heat source may be even further downstream than the downstream end of the downstream portion of the containment wrap.

In some embodiments, aerosol generating articles of the invention containing continuous combustible heat sources include one or more air inlets located adjacent the downstream end of the aerosol generating substrate.

In use, air drawn along one or more air flow passages of the aerosol generating articles of the present invention containing a continuous combustible heat source does not pass through any air flow passages along the continuous combustible heat source. The absence of any air flow passages through the continuous combustible heat source preferably generally prevents or suppresses combustion activation of the continuous combustible heat source during a puff by the user. This essentially prevents or suppresses temperature peaks in the aerosol-forming substrate during a puff by the user. By preventing or suppressing combustion activation of a continuous combustible heat source and thereby preventing or suppressing excessive temperature increases in the aerosol-forming substrate, combustion or pyrolysis of the aerosol-forming substrate can be advantageously prevented under intense puffing conditions. In addition, the effect of the user's puffing pattern on the composition of the mainstream aerosol may be preferably minimized or reduced.

The addition of a continuous combustible heat source may also advantageously generally prevent or suppress combustion and decomposition products and other materials generated by ignition and combustion of the continuous combustible heat source into the air drawn through the aerosol generating articles of the present invention when in use. This is particularly advantageous if the continuous combustible heat source contains one or more additives that promote ignition or combustion of the continuous combustible heat source.

In the aerosol generating articles of the present invention containing a continuous combustible heat source, heat transfer from the solid combustible heat source to the aerosol generating substrate occurs primarily by thermal conduction. Heating of the aerosol-forming substrate due to forced convection is minimized or reduced. This may advantageously help to minimize or reduce the influence of the user's puffing pattern on the aerosol composition of the mainstream products of the invention.

In aerosol generating articles of the present invention containing a continuous combustible heat source, it is particularly important to optimize conductive heat transfer between the combustible heat source and the aerosol generating substrate. As further described below, the presence of one or more thermal conductive elements located around at least the rear portion of the combustible carbon heat source and at least the front portion of the aerosol generating substrate is particularly preferred in the aerosol generating articles of the present invention containing continuous heat sources , while the heating of the substrate forming the aerosol due to forced convection is insignificant or completely absent.

In some embodiments, the combustible heat source includes at least one longitudinal air flow passage providing one or more passages for air flow through the heat source. As used herein, the term "air flow channel" is used to describe a channel extending along the length of a heat source through which air can be drawn through the aerosol generating article. Such heat sources containing one or more longitudinal air flow channels are referred to herein as "non-continuous" heat sources.

The diameter of the at least one longitudinal air flow channel may be from about 1.5 millimeters to about 3 millimeters, more preferably from about 2 millimeters to about 2.5 millimeters. The inner surface of the at least one longitudinal air flow channel may be partially or completely covered, as described in more detail in WO-A-2009/022232.

Preferably, the combustible heat source has a length of from about 7 millimeters to about 17 millimeters, more preferably from about 7 millimeters to about 15 millimeters, most preferably from about 7 millimeters to about 13 millimeters. In some embodiments, the combustible heat source is approximately 9 millimeters in length.

Preferably, the combustible heat source has a diameter of from about 5 millimeters to about 9 millimeters, more preferably from about 7 millimeters to about 8 millimeters.

In the context of this invention document, the term "aerosol-forming substrate" is used to describe a substrate capable of releasing volatile compounds when heated that can form an aerosol. Aerosols generated from aerosol-forming substrates, aerosol-generating articles, according to the present invention may be visible or invisible and may contain vapors (for example, fine particles of substances that are in a gaseous state and are usually liquid or solid at room temperature), and also gases and liquid droplets of condensed vapor.

The aerosol-forming substrate may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may contain both solid and liquid components. The aerosol-forming substrate may comprise tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may further comprise one or more aerosol-forming substances. Examples of suitable aerosol-forming substances include, but are not limited to, glycerin and propylene glycol.

The aerosol-forming substrate may be a rod that contains tobacco-containing material.

If the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may comprise, for example, one or more of the following: powder, granules, beads, grains, thin tubes, strips or sheets containing one or more more of the following: herbal leaves, tobacco leaves, tobacco stem fragments, reconstituted tobacco, homogenized tobacco, extruded tobacco and blasted tobacco. The solid aerosol-forming substrate may be in loose form or may be provided in a suitable container or cartridge. For example, the aerosol-forming material of the solid aerosol-forming substrate may be contained in a paper or other wrapper and shaped like a rod. If the aerosol-forming substrate is in the form of a rod, then the entire rod, including any wrapping, is considered to be the aerosol-forming substrate.

Optionally, the solid aerosol substrate may contain additional tobacco or non-tobacco volatile aromatic compounds designed to be released upon heating of the solid aerosol substrate. The solid aerosol-forming substrate may also contain capsules that, for example, contain additional tobacco or non-tobacco volatile flavor compounds, and such capsules may melt when the solid aerosol-forming substrate is heated.

If desired, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may be in the form of powder, granules, beads, grains, thin tubes, strips or sheets. The solid aerosol-forming substrate may be applied to the surface of the carrier in the form of, for example, a sheet, foam, gel or slurry. The solid aerosol-forming substrate may be applied to the entire surface of the carrier, or alternatively may be applied in a pattern to provide uneven delivery of the flavor during use.

The aerosol-forming substrate may take the form of a rod or segment containing a material capable of releasing volatile compounds when heated and surrounded by a paper or other wrapper. If the aerosol-forming substrate is in the form of such a rod or segment, then the entire rod or segment, including any wrapper, is considered to be the aerosol-forming substrate.

The aerosol-forming substrate preferably has a length of from about 5 millimeters to about 20 millimeters. In certain embodiments, the aerosol-forming substrate may have a length from about 6 millimeters to about 15 millimeters, or a length from about 7 millimeters to about 12 millimeters.

The aerosol-forming substrate may comprise a rod of tobacco-based material wrapped in Ficella. In preferred embodiments, the aerosol-forming substrate comprises a rod of homogenized tobacco-based material wrapped in Ficella.

In any of the above-described embodiments, the combustible heat source and the aerosol-forming substrate may abut each other in coaxial alignment. In the context of this invention document, the words "butting" and "butting" are used to describe a component or part of a component that is in direct contact with another component or part of a component. This includes embodiments in which the combustible heat source comprises a non-combustible partition between its downstream surface and the aerosol-forming substrate, wherein the non-combustible partition is in direct contact with the aerosol-forming substrate.

The aerosol generating articles of the present invention may comprise a thermally conductive element located around and in direct contact with both at least a rear portion of the combustible heat source and at least a front portion of the aerosol generating substrate. In such embodiments, the thermal conductive element provides thermal coupling between the combustible heat source and the aerosol-forming substrate of the aerosol-generating articles of the invention and preferably helps ensure sufficient heat transfer from the combustible heat source to the aerosol-forming substrate to form an acceptable aerosol.

The aerosol generating articles of the present invention may comprise a thermally conductive element that is so remote from one or both of the combustible heat source and the aerosol-forming substrate that there is no direct communication between the thermally conductive element and one or both of the combustible heat source and the aerosol-forming substrate. contact.

If the aerosol generating article includes a thermal conductive element located around at least a rear portion of the combustible heat source and at least a forward portion of the aerosol generating substrate, the thermal conductive element may be formed by a containment wrap. For example, the containment wrap may contain one or more layers of thermally conductive material that form one or more thermally conductive elements.

The thermal conductive element is preferably non-flammable. In certain embodiments, the thermal conductive element may limit the flow of oxygen. In other words, one or more thermal conductive elements may suppress or prevent the passage of oxygen through the thermal conductive element.

Suitable thermal conductive members include, but are not limited to, metal foil wrappers such as, for example, aluminum foil wrappers, steel wrappers, iron foil wrappers, and copper foil wrappers; and metal alloy foil wrappers.

The aerosol generating articles of the present invention may comprise a transmission element or separating element located downstream of the aerosol generating substrate. Such an element may take the form of a hollow tube located downstream of the aerosol-forming substrate.

The transmission element may abut one or both of the aerosol-forming substrate and the mouthpiece. Alternatively, the transfer element may be removed from one or both of the aerosol-forming substrate and the mouthpiece.

The presence of the transfer element preferably allows the aerosol generated by transferring heat from the combustible heat source to the aerosol-forming substrate to be cooled. The presence of the transfer element also advantageously allows the overall length of the aerosol generating article to be adjusted to a desired value, for example to a length similar to that of a traditional cigarette, based on appropriate selection of the length of the transfer element.

The transmission element may have a length of from about 7 millimeters to about 50 millimeters, for example a length from about 10 millimeters to about 45 millimeters, or from about 15 millimeters to about 30 millimeters. The transmission element may have a different length depending on the overall length of the aerosol generating article required and the presence and length of other components in the aerosol generating article.

Preferably, the transmission element comprises at least one tubular hollow body with an open end. In such embodiments, when used, air drawn into the aerosol generating article passes through at least one open-ended tubular hollow body as it passes downstream through the aerosol generating article from the aerosol generating substrate to the distal end aerosol generating product.

The transfer element may comprise at least one open-ended tubular hollow body made of one or more suitable materials that are substantially thermally stable at the temperature of the aerosol generated by transferring heat from the combustible heat source to the aerosol-forming substrate. Suitable materials are known in the art and include, but are not limited to, paper, cardboard, plastics such as cellulose acetate, ceramics, and combinations thereof.

The aerosol generating articles of the invention may comprise an aerosol cooling element or a heat exchanger downstream of the aerosol generating substrate. The aerosol cooling element may comprise several channels extending in the longitudinal direction. If the aerosol generating article includes a transmission element downstream of the aerosol generating substrate, the aerosol cooling element is preferably located downstream of the transmission element.

The aerosol cooling element may comprise an assembled sheet of material selected from the group consisting of metal foil, polymeric material, and substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may comprise an assembled sheet of material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA) ) and aluminum foil.

In some preferred embodiments, the aerosol cooling element may comprise an assembled sheet of biodegradable polymeric material, such as polylactic acid (PLA) or Mater-Bi® grade material (a commercially available series of starch-based copolyesters).

Preferably, the aerosol generating article includes a mouthpiece downstream of the aerosol generating substrate, which is located at the downstream end of the aerosol generating article. The mouthpiece may contain a filter. For example, the mouthpiece may include a filter rod having one or more segments. If the mouthpiece includes a filter rod, the filter rod is preferably a single segment filter rod. The filter rod may contain one or more segments containing cellulose acetate, paper or other suitable known filter materials or combinations thereof. Preferably, the filter rod contains a filter material with low filtration efficiency.

The aerosol generating articles of the present invention may comprise multiple elements assembled into a rod.

In the context of this invention document, the term “aerosol generating article” is used to refer to an article containing an aerosol generating substrate that is capable of releasing volatile compounds that can form an aerosol. The aerosol generating product may be a non-flammable aerosol generating product, which is an article that releases volatile compounds without burning the aerosol-generating substrate. The aerosol generating article may be a heated aerosol generating article. As used herein regarding the invention, the term “heatable aerosol generating article” is used herein to refer to an aerosol generating article containing an aerosol generating substrate that is intended to be heated rather than burned to release volatile compounds that can form an aerosol. The heated aerosol generating article may comprise an integral heating means integral to the aerosol generating article or may be configured to interface with an external heater integral to a separate aerosol generating device.

The aerosol generating article may have a substantially cylindrical shape. The aerosol generating article may be substantially oblong. The aerosol-forming substrate may have a substantially cylindrical shape. The aerosol-forming substrate may be substantially oblong. The aerosol-forming substrate may be located in the aerosol-generating article such that the length of the aerosol-forming substrate is substantially parallel to the direction of air flow in the aerosol-generating article.

The transmitting part or element may be substantially elongated.

The aerosol generating article can be of any desired length. For example, the aerosol generating article may have an overall length of from about 65 millimeters to about 100 millimeters. The aerosol generating article may have any desired outer diameter. For example, the aerosol generating article may have an outer diameter of from about 5 millimeters to about 12 millimeters.

The aerosol generating article may be surrounded by an outer wrapper, such as cigarette paper, which has low air permeability. This wrap can be used in addition to the containment wrap of the present invention. Alternatively, if the downstream portion of the containment wrap extends to the downstream end of the aerosol generating article, then the containment wrap can be used to connect all of the components of the aerosol generating article. In this case, it may not be necessary to provide additional outer wrapping.

Alternatively or in addition, the mouthpiece may be surrounded by rim paper.

It should also be understood that specific combinations of the various features described and defined in any aspects of the present invention may be implemented and/or provided and/or used independently.

The invention will now be described by way of example only with reference to the accompanying drawings, in which:

In fig. 1 is a schematic cross-sectional view of an aerosol generating article according to the present invention.

In fig. 2 is a perspective view of the upstream end of an aerosol generating article in accordance with the present invention.

In fig. 3 is a perspective view of the upstream end of yet another aerosol generating article in accordance with the present invention.

In fig. 4 is a perspective view of the upstream end of yet another aerosol generating article in accordance with the present invention.

In fig. 5-9 are schematic top-down views of the upstream end of aerosol generating articles in accordance with the present invention.

In fig. 10-12 show temperature profiles for various smoking articles, including the smoking articles shown in FIG. 5-9.

In fig. 1 shows an aerosol generating article 2 according to a first embodiment of the invention. The aerosol-generating product 2 contains a continuous combustible heat source 4 having a front surface 6 and a rear surface 8 opposite it, and a substrate 10 that forms an aerosol. The combustible heat source 4 is substantially cylindrical and comprises a longitudinal outer surface extending between the front surface 6 and an opposing rear surface 8. The aerosol generating article 2 further comprises a transmission element 12 downstream of the aerosol generating substrate 10, element 14 , cooling the aerosol, downstream relative to the transmitting element 12, a separating element 16 further downstream relative to the aerosol cooling element 14, and a mouthpiece 18 further downstream relative to the separating element 16.

The solid combustible heat source 4 is a solid carbon combustible heat source and is located at the upstream end of the aerosol generating product 2. As shown in FIG. 1, between the rear surface 8 of the solid combustible heat source 4 and the aerosol-forming substrate 10, a non-combustible, substantially airtight partition 22 in the form of a disk of aluminum foil is provided. The partition 22 is applied to the back surface 8 of the solid combustible heat source 4 by pressing the aluminum foil disk against the back surface 8 of the solid combustible heat source 4 and is adjacent to the back surface 8 of the combustible carbon heat source 4 and the aerosol-forming substrate 10.

In other embodiments (not shown), there may be no non-combustible, substantially airtight barrier 22 between the rear surface 8 of the solid combustible heat source 4 and the aerosol-forming substrate 10.

The substrate 10, which forms the aerosol, is located immediately downstream relative to the partition 22, superimposed on the rear surface 8 of the continuous combustible heat source 4. The aerosol-forming substrate 10 comprises a cylindrical rod of homogenized tobacco material 24 containing an aerosol-forming agent, such as glycerin, which is wrapped in ficella 26.

The transfer element 12 is located immediately downstream of the aerosol-forming substrate 10 and contains a cylindrical, hollow, open-ended cellulose acetate tube 28.

The aerosol cooling element 14 is located immediately downstream of the transfer element 12 and contains an assembled sheet of biodegradable polymeric material such as, for example, polylactic acid.

The separating element 16 is located immediately downstream of the aerosol cooling element 14 and contains a cylindrical hollow paper or cardboard tube 30 with an open end.

The mouthpiece 18 is located immediately downstream of the separating element 16. As shown in FIG. 1, the mouthpiece 18 is located at the proximal end of the aerosol generating article 2 and includes a cylindrical rod of a suitable filter material 32, such as, for example, cellulose acetate tow, with very low filtration efficiency, which is wrapped with filter rod ficell 34.

As shown in FIG. 1, the aerosol generating article 2 further includes a retaining wrap 35. The retaining wrap 35 includes an upstream portion 31 that extends the entire length of the combustible heat source 4 along the longitudinal outer surface of the combustible heat source 4. The upstream portion 31 of the retaining wrap 35 contains a first 41 and a second 42 opening. The first and second openings 41, 42 extend completely through the containment wrap 35 exposing a portion of the combustion heat source 4 that is covered by the first and second openings 41, 42. The first and second openings 41, 42 cover at least about 30 percent of the longitudinal outer surface of the combustion source 4 warmth. The first and second openings 41, 42 are both the same size and substantially rectangular. The first and second openings 41, 42 are evenly distributed throughout the combustible heat source 4. The first and second openings 41, 42 are limited on all sides by a retaining wrap 35, which provides a ring of retaining wrap 35 at the upstream end of the combustible heat source 4. The upstream edges of the first and second openings 41, 42 are located at a distance of approximately 1 millimeter from the upstream end of the combustible heat source 4, so that the length of the ring of retaining wrap 35 at the upstream end of the combustible heat source 4 is approximately 1 millimeter.

The containment wrap 35 further includes a downstream portion 33 that surrounds a portion of the aerosol-forming substrate 10. In the aerosol generating article 2 shown, the containment wrap 35 encloses only a portion of the aerosol generating substrate 10 that extends from the upstream end of the aerosol generating substrate 10 toward the downstream end of the aerosol generating substrate 10. However, it should be understood that the containment wrap 35 may surround more or less of the aerosol-forming substrate 10. For example, the containment wrap 35 may surround the entire longitudinal surface of the aerosol-forming substrate 10.

The containment wrap 35 contains a layer of aluminum foil 36 located closest to the combustible heat source 4 and the aerosol-forming substrate 10. The aluminum foil layer 36 has a thickness of approximately 20 micrometers. The aluminum foil layer 36 serves as a heat-conducting element. The retaining wrap 35 further includes a layer of paper combined with a layer of metal 37. The layer of paper combined with a layer of metal 37 has a thickness of approximately 50 micrometers. A layer of aluminum foil 36 is attached to a layer of paper combined with a layer of metal 37. The holding wrap 35 is adhered to the combustible heat source 4 by means of silicate adhesive.

The components of the aerosol generating article 2 are held together by an outer wrap 20. The outer wrap 20 extends over a portion of the combustible heat source 4, although it should be understood that in other aerosol generating articles 2 the outer wrap 20 does not extend over the combustible heat source 4.

The aerosol generating article 2, around the circumference of the aerosol generating substrate 10, includes one or more air inlets 40.

As shown in FIG. 1, circumferential placement of air inlet holes 40 in the ficell 26 of the aerosol-forming substrate 10, the containment wrap 35, and the outer wrap 20 is provided to allow cool air (shown in dotted arrows in FIG. 1) to enter the aerosol-forming substrate 10.

The multi-segment component 50 may further include a removable cover (not shown) at its distal end that is immediately adjacent to the heat source 4. For example, compared to a heat source that is wrapped in a portion of one or both of the outer wrapper 20 and the wrapper 38 and connected to the remainder of such wrapper along a weakened line containing a plurality of perforations in the wrapper, the removable cover may include a central portion containing a desiccant such like glycerin, to absorb moisture. In such examples, to use the aerosol generating product, the user removes the removable cover by pinching and squeezing the sides of the cover between the thumb and forefinger. When the lid is compressed, sufficient force is applied to the weakened line to locally rupture the wrapper by which the lid is attached. The user then removes the cap by twisting the cap to break the remaining portion of the weakened line. Once the cap is removed, the heat source is partially exposed, allowing the user to ignite the aerosol-generating product.

In use, the user ignites the solid combustible heat source 4 of the aerosol generating article 2 according to the first embodiment of the invention and then takes a puff through the mouthpiece 18. When the user takes a puff through the mouthpiece 18, air (indicated by dotted arrows in FIG. 1) is drawn into the substrate 10 the aerosol generating article 2 through the air inlets 40.

The front part of the substrate 10, which forms the aerosol, is heated by heat transfer through the rear surface 8 of the continuous combustible heat source 4 and the partition 22.

In fig. 2 is a perspective view of the upstream end of the aerosol generating article shown in FIG. 1. In FIG. 2 the front surface 6 of the combustible heat source 4 is clearly visible. The first and second openings 41, 42 in the containment wrap 35 are clearly visible, as is the ring of the containment wrap 35 at the upstream end of the combustible heat source. Also shown is the placement of the air inlet holes 40 around the circumference.

In fig. 3 is a perspective view of the upstream end of another aerosol generating article. It should be understood that the aerosol generating article 2 in FIG. 3 contains all the features described in relation to the aerosol generating article 2 in FIG. 1 and 2, and differs only in the device of the holding wrap 35.

Aerosol generating product 2 in FIG. 3 includes a retaining wrap 35. The retaining wrap 35 includes an upstream portion that extends the entire length of the combustible heat source 4 along the longitudinal outer surface of the combustible heat source 4. The upstream portion of the containment wrap 35 contains at least a first 51, a second 52 and a third 53 opening. It should be understood that the retention wrap 35 shown in FIG. 3 may also contain holes and they are shown in the perspective view in FIG. 3 may not be visible.

The holes 51, 52, 53 extend to the upstream end of the containment wrap 35. Consequently, the holes 51, 52, 53 extend to the upstream end of the combustible heat source 4. Accordingly, the upstream ends of the holes 51, 52, 53 are limited by the upstream edge of the containment wrap 35. Consequently, the holes 51, 52, 53 are not completely surrounded by the containment wrap 35, as is the case in FIG. 2. The retaining wrap 35 therefore comprises a plurality of strips which extend towards the upstream end of the combustible heat source 4 .

In fig. 4 is a perspective view of the upstream end of another aerosol generating article. It should be understood that the aerosol generating article 2 in FIG. 3 contains all the features described in relation to the aerosol generating article 2 in FIG. 3, and differs only in the device of the holding wrap 35.

Unlike shown in FIG. 3 product 2 generating aerosol, in FIG. 4 includes a retaining wrap that does not extend to the upstream end of the combustible heat source. In other words, the upstream end of the upstream portion of the containment wrap is located at a distance from the upstream end of the combustible heat source.

In fig. 5-9 are schematic top-down views of the upstream end of aerosol generating articles in accordance with the present invention. Each of the aerosol generating articles 2 includes a containment wrap 35 comprising an upstream portion that extends the entire length of the combustible heat source 4 along the longitudinal outer surface of the combustible heat source 4 . The upstream portion of the containment wrap contains two openings 41, 51, only one of which is visible in each of FIGS. 5-9. The second hole, which is not shown, is of the same size and shape as the shown holes 41, 51, and is located on the opposite side of the combustible heat source 4.

In fig. 5 and 6 show aerosol generating articles 2 comprising a containment wrap 35 which includes holes 51 that extend the entire distance to the upstream end of the containment wrap 35, as is the case in FIG. 3.

Hole 51 shown in FIG. 5 includes a narrow portion at the upstream end of the opening 51. The wider portion of the opening 51 shown in FIG. 4 is 4.5 millimeters long (shown at 60) and 10 millimeters wide (shown at 61). The narrow portion of the hole 51 has a length of 1.5 millimeters (shown by reference number 62) and a width of 2 millimeters (shown by reference number 63).

Hole 51 shown in FIG. 6 includes a narrow portion at the downstream end of the opening 51. The wider portion of the opening 51 shown in FIG. 6 is 4.5 millimeters long (shown at 60) and 10 millimeters wide (shown at 61). The narrow portion of the hole 51 has a length of 1.5 millimeters (shown by reference number 62) and a width of 2 millimeters (shown by reference number 63). The area of each of the holes 51 shown in both of FIGS. 5 and 6, is 48 millimeters square. Since each aerosol generating article 2 contains two identical openings 51, the total area of the combustible heat source 4 occupied by the openings 51 in FIG. 5 and 6, is 96 millimeters square. In aerosol generating products 2 in FIG. 5 and 6, the holes 51 in the containment wrap cover approximately 65 percent of the longitudinal outer surface of the combustible heat source 4.

In fig. 7, 8 and 9 show aerosol generating articles 2 comprising a containment wrap 35 which includes openings 41 that do not extend the entire distance to the upstream end of the containment wrap 35, but which are completely confined by the containment wrap 35 to form a continuous ring. holding wrap 35 at the upstream end of the combustible heat source 4.

The holes 41 shown in both of FIGS. 7 and 8, have a length of 4.5 millimeters (shown by reference number 70) and a width of 10 millimeters (shown by reference number 71).

The area of each of the holes 41 shown in both of FIGS. 7 and 8, is 45 millimeters square. Since each aerosol generating article 2 contains two identical openings 41, the total area of the combustible heat source 4 occupied by the openings 41 in FIG. 7 and 8, is 90 millimeters square. In aerosol generating products 2 in FIG. 7 and 8, the holes 41 in the containment wrap cover approximately 61 percent of the longitudinal outer surface of the combustible heat source 4.

The upstream end of the opening 41 in FIG. 7 is located at a distance of 1.5 millimeters from the upstream end of the combustible heat source 4 (as indicated by reference number 72).

The upstream end of the opening 41 in FIG. 8 is located at a distance of 2.5 millimeters from the upstream end of the combustible heat source 4 (as indicated by reference number 74).

Hole 41 shown in FIG. 9 is 5.5 millimeters long (shown at 75) and 10 millimeters wide (shown at 71).

The area of the hole 41 shown in FIG. 9, is 55 millimeters square. Since each aerosol generating article 2 contains two identical openings 41, the total area of the combustible heat source 4 occupied by the openings 41 in FIG. 9, is 110 millimeters square. In the aerosol generating product 2 in FIG. 9, the holes 41 in the containment wrap cover approximately 65.8 percent of the longitudinal outer surface of the combustible heat source 4.

The upstream end of the opening 41 in FIG. 9 is located at a distance of 1.5 millimeters from the upstream end of the combustible heat source 4 (as indicated by reference number 72).

The aerosol generating articles 2 shown in FIG. 5, 6 and 7 contain openings 41 whose downstream ends are located approximately 3 millimeters closer than the downstream end of the combustible heat source.

The aerosol generating articles 2 shown in FIG. 8 and 9 contain openings 41 whose downstream ends are located approximately 2 millimeters closer than the downstream end of the combustible heat source.

In fig. 10-12 show the temperature profiles of the aerosol generating articles shown in each of FIGS. 5-9, which are taken at different points in the aerosol-generating product.

The smoking articles shown in FIG. 5-9 were manufactured in accordance with the method according to the present invention. Each smoking article was maintained at approximately 22 degrees Celsius and approximately 45 percent relative humidity for 24 hours. The downstream ends of each smoking article were inserted into the smoking machine, the combustible heat sources were ignited, and each aerosol generating article was subjected to the same puff cycle. The temperature of the tobacco rod was measured using a thermocouple throughout the puff cycle to obtain temperature profiles showing the temperature of the tobacco rod as a function of time. In the temperature profiles shown in FIG. 10-12, temperature is shown on the vertical axis 110 and is given in degrees Celsius, and time is shown on the horizontal axis and is given in seconds.

In the temperature profiles shown in FIG. 10-12, line 101 represents the temperature profile for the aerosol generating article shown in FIG. 5; line 103 represents the temperature profile for the aerosol generating product shown in FIG. 6; line 104 represents the temperature profile for the aerosol generating article shown in FIG. 7; line 104 represents the temperature profile for the aerosol generating article shown in FIG. 8; and line 105 represents the temperature profile for the aerosol generating article shown in FIG. 9.

A control aerosol generating product was also tested under the same conditions. The control aerosol generating article contained the same features as those shown in FIG. 5-9. However, the control aerosol generating article did not contain a containment wrap having an upstream portion the extent of which along the combustible heat source relative to the longitudinal outer surface of the combustible heat source is at least approximately 50 percent of its length, and therefore did not comply with the present invention. As a result, the combustible heat source of the reference aerosol generating article is exposed significantly more than the combustible heat source of the aerosol generating article shown in FIG. 5-9. In the temperature profiles shown in FIG. 10 and 11, line 106 represents the temperature profile for the control aerosol generating article.

In fig. 10 shows temperature profiles, measured by thermocouple, in an aerosol generating substrate located approximately 2 millimeters downstream of the upstream end of the aerosol generating substrate.

In fig. 11 shows temperature profiles, measured by thermocouple, in an aerosol generating substrate located approximately 1 millimeter downstream of the upstream end of the aerosol generating substrate.

In fig. 12 shows temperature profiles, measured by thermocouple, in an aerosol generating substrate located approximately 7 millimeters downstream of the upstream end of the aerosol generating substrate.

As can be understood from the temperature profiles shown in FIG. 10-12, temperature profiles of the aerosol generating products shown in FIG. 5-9 are similar to the temperature profiles for the control aerosol generating product. Moreover, in all of FIGS. 10-12 aerosol generating substrates of the aerosol generating articles shown in FIG. 5-9 are actually at a higher temperature than the aerosol-generating substrate of the control aerosol-generating article for at least about 200 seconds in the puff cycle. Maintaining a high temperature in the aerosol-forming substrate is associated with improved aerosol generation. Maintaining a high temperature later in the graph is associated with an improvement in the duration of aerosol generation from the aerosol generating substrate. Consequently, it was unexpectedly found that the presence of a containment wrap having an upstream portion that extends along the combustible heat source relative to the longitudinal outer surface of the combustible heat source is at least about 50 percent of its length did not have such a significant adverse effect on performance. characteristics of the combustible heat source such that the combustible heat source is rendered non-functional in the aerosol generating article.

Moreover, from FIG. 12 it can be seen that even at the far downstream end of the aerosol generating substrate, at a distance of 7 millimeters from the upstream end of the aerosol generating substrate, the aerosol generating articles of the present invention maintain temperatures similar to those of the control article 106, generating an aerosol. This is particularly advantageous as it demonstrates that the aerosol-forming substrates of the present invention are heated along their entire length, making it possible to generate an aerosol over a large portion of the aerosol-forming substrate.

In addition, it was concluded that from the aerosol generating products shown in FIG. 5-9, the aerosol generating product shown in FIG. 5, with the temperature profile shown by line 101. As can be understood from FIG. 10-12, the aerosol generating substrate of the aerosol generating article shown in FIG. 5 was able to maintain the highest temperature for the longest time. In particular, in both of FIGS. 10-12 it can be seen that the temperature of the aerosol-generating substrate, the aerosol-generating article shown in FIG. 5 is unexpectedly higher at the end of the puff cycle than the temperatures of the aerosol-generating substrates in other aerosol-generating products of the present invention.

A method for manufacturing an aerosol-generating product is also proposed. The method includes providing a specified length of paper. The paper is paper combined with a layer of metal. In some embodiments, a piece of aluminum foil is then added to the paper. At least one hole is then cut through the piece of aluminum and paper to create a retaining wrap. At least one hole is produced using a stamping process. The material (paper and aluminum foil) limited by the cut line is removed to create an opening. The containment wrap is then applied to the combustible heat source and the aerosol-forming substrate such that the upstream portion of the containment wrap along the combustible heat source relative to the longitudinal outer surface of the combustible heat source is at least about 50 percent of its length, with There is at least one opening upstream of the containment wrapper portion and a downstream portion of the containment wrapper surrounds at least a portion of the aerosol-forming substrate.

The above specific embodiments and examples illustrate, but do not limit, the invention. It should be understood that other embodiments of the invention may be proposed, and the specific embodiments and examples described herein are not exhaustive.

Claims (29)

1. An aerosol generating product containing: a combustible heat source having a longitudinal outer surface; the aerosol-forming substrate is further downstream of the combustible heat source; And a retaining wrap containing: an upstream portion extending at least 50 percent along the length of a combustible heat source on a longitudinal outer surface of the combustible heat source and containing at least one opening, wherein the at least one opening covers at least 30 percent of the longitudinal outer surface combustible heat source, and a downstream portion surrounding at least a portion of the aerosol-forming substrate. 2. The aerosol generating article of claim 1, wherein the upstream portion of the containment wrap extends to the upstream end of the combustible heat source or extends beyond the upstream end of the combustible heat source. 3. The aerosol generating product according to claim 1 or 2, characterized in that at least one opening in the upstream portion of the containment wrap has a total area of at least 45 square millimeters. 4. An aerosol generating product according to any of the previous claims, characterized in that the upstream portion of the retaining wrap is glued to the surface of the combustible heat source. 5. An aerosol generating product according to any of the previous claims, characterized in that the holding wrapper contains metal foil. 6. An aerosol generating product according to any of the previous claims, characterized in that the holding wrapper contains paper. 7. The aerosol generating product according to claim 6, characterized in that the paper contains at least one of paper combined with a metal layer or metallized paper. 8. An aerosol generating product according to any of the preceding claims, characterized in that the containment wrap has a maximum thickness of no more than 190 micrometers. 9. An aerosol generating article according to any of the preceding claims, characterized in that at least one opening in the containment wrapper comprises an opening surrounded on all sides by the containment wrapper. 10. The aerosol generating product according to claim 9, characterized in that the upstream end of the at least one opening is located at a distance of at least 1 millimeter from the upstream end of the combustible heat source. 11. Product for generating an aerosol according to any one of paragraphs. 1-8, characterized in that the at least one opening extends to an upstream end of the containment wrap such that the at least one opening in the containment wrap is not surrounded on all sides by the containment wrap. 12. The aerosol generating article of any one of the preceding claims, wherein the upstream portion of the containment wrap extends to the upstream end of the combustible heat source, wherein the containment wrap contains both metal foil and paper combined with a layer of metal, or metallized paper, and at least one hole covers from 50 percent to 90 percent of the longitudinal outer surface of the combustible heat source. 13. A method for producing an aerosol generating product, wherein the method includes the steps of: provide a combustible heat source and an aerosol-forming substrate, provide part of the wrapper material, making at least one hole in a portion of the wrapper material to form a retaining wrapper, Apply a containment wrap to the combustible heat source and the aerosol-forming substrate such that an upstream portion of the containment wrap extends at least 50 percent along the length of the combustible heat source on a longitudinal outer surface of the combustible heat source, wherein at least one opening is located in the upstream portion of the containment wrap, wherein at least one one opening covers at least 30 percent of the longitudinal outer surface of the combustible heat source; And a downstream portion of the containment wrap surrounds at least a portion of the aerosol-forming substrate. 14. The method according to claim 13, characterized in that the step of providing a portion of the wrapper material includes: providing a portion of paper combined with a layer of metal or metallized paper; providing a metal foil part; And attaching a piece of metal foil to a piece of paper. 15. The method of claim 14, wherein the step of making at least one hole in the portion of the wrapper material includes making one hole in both the paper portion combined with a layer of metal or metallized paper and the metal portion. foil.