WO2015028812A1

WO2015028812A1 - Smoking article

Info

Publication number: WO2015028812A1
Application number: PCT/GB2014/052621
Authority: WO
Inventors: Edward Dennis John; David John Dittrich; Steven Coburn; Chuan Liu; Kevin Gerard Mcadam
Original assignee: British American Tobacco (Investments) Limited
Priority date: 2013-08-30
Filing date: 2014-08-29
Publication date: 2015-03-05
Also published as: EP3038478A1; RU2642388C2; AU2014313946B2; GB201315492D0; CA2920952A1; US20160205996A1; RU2016111732A; AU2014313946A1; CA2920952C

Abstract

A method of producing a smoking article is disclosed. The smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of a smoke constituent generated by a smoking article in use. The method comprises in a first step, determining one or more first lateral regions at which, when the smoking article is in use, the smoke constituent is present at a first concentration, and one or more second lateral regions at which, when the smoking article is in use, the smoke constituent is present at a second concentration which is lower than the first concentration. In a second step, the method comprises producing a smoking article in which the smoke constituent reducing technology is targeted to reduce the concentration of the smoke constituent present at the one or more first lateral regions.

Description

Smoking Article

Technical Field

The invention relates to smoking articles and methods for making smoking articles.

Background

Smoke produced when smoking articles, such as cigarettes, are combusted is known to contain many different constituents. Smoking articles frequently comprise a filter to remove constituents from the smoke that is drawn from the smokeable material.

Summary

According to a first aspect, a method of making a smoking article is provided. In use, the smoking article generates smoke having a smoke constituent. The smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of the smoke constituent. The method comprises:

1) determining one or more first lateral regions at which, when the smoking article is in use, the smoke constituent is present at a first

concentration, and one or more second lateral regions at which, when the smoking article is in use, the smoke constituent is present at a second

concentration which is lower than the first concentration; and,

2) producing a smoking article in which the smoke constituent reducing technology is targeted to reduce the concentration of the smoke constituent present at the one or more first lateral regions.

According to a second aspect, a method of reducing the concentration of a smoke constituent in the smoke produced by a smoking article is provided. The smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of the smoke constituent in smoke. The method comprises:

l) determining one or more first lateral regions at which, when the smoking article is in use, the smoke constituent is present at a first

concentration which is lower than the first concentration; and,

The smoke constituent reducing technology may be located in the one or more first lateral regions. The smoke constituent reducing technology may or may not also be located in the one or more second lateral regions.

The amount of smoke constituent reducing technology located in the one or more first lateral regions may be greater than the amount located in the one or more second lateral regions.

The smoke constituent reducing technology may be included in any suitably appropriate amount sufficient to ensure that the concentration of the target smoke constituent in smoke is reduced. For example, the relative amounts of smoke constituent reducing technology located in the first and second regions may be proportional to the relative first and second concentrations of the smoke constituent. In other embodiments, the relative amounts of smoke constituent reducing technology and concentrations of the smoke constituent may not be proportional.

The smoking article may comprise a rod of smokeable material, and in this case, the first and second lateral regions may be regions of the rod of smokeable material. The rod of smokeable material may be generally cylindrical in shape and in this case, the first and second lateral regions may be located on a diametrical line across the width of the cylinder.

The smoke reducing technology may be located at the one or more first and/or second lateral regions. In addition, or alternatively, the smoke reducing technology may be located in a region of the smoking article which is away from the one or more first and/or second lateral regions. For example, the smoking article may comprise a filter and in this case, the smoke constituent reducing technology may be located within the filter to reduce the concentration of the smoke constituent present at the one or more first lateral regions. The filter may comprise a smoke reducing technology to reduce the concentration of the smoke constituent generated at the one or more first lateral regions. In addition, or alternatively, the filter may contain a plurality of smoke reducing technologies, targeted to reduce concentrations of the smoke constituent or smoke

constituents generated in both the first and second lateral regions.

The rod of smokeable material and/or the smoking article filter may comprise portions of varying density to create controlled pressure drop regions to control airflow through the smoking article. The smoking article may comprise a plurality of different smoke constituent reducing technologies. For example, there may be two different smoke constituent reducing technologies included in the smoking article. In this case, the two different smoke constituent reducing technologies may be located in the same one or more first lateral regions. Alternatively, the two different smoke constituent reducing technologies may be located in different lateral regions, which may include the first and/or second lateral regions, and/or alternative regions.

For example, it may be desirable to reduce smoke constituent levels in both the one or more first and second lateral regions. To achieve this, smoke constituent reducing technologies, which may be the same or different technologies, may be included at the one or more second lateral regions in addition to the one or more first lateral regions. The plurality of different smoke constituent reducing technologies may be directed towards the same or different smoke constituents.

The smoking article may comprise a co-axial rod comprising an outer rod of smokeable material circumscribed by an outer wrapper, the outer rod comprising an inner rod of smokeable material circumscribed by an inner wrapper. The inner wrapper may be permeable or impermeable to the passage of smoke constituents.

The inner wrapper may comprise the smoke constituent reducing technology.

The smokeable material of the inner and / or outer rod may comprise the smoke constituent reducing technology.

The outer wrapper may be permeable or impermeable to the passage of smoke constituents.

The outer wrapper may comprise the smoke constituent reducing technology.

The inner and/or outer rods may be wrapped in a plurality of wrappers, one or more of which may comprise the smoke constituent reducing technology. For example, particulate sorbent material may be adhered to one or more surfaces of one or more of the wrappers. The particulate sorbent material may cover the entire surface or surfaces, or may be present in one or more discrete patches on the surface or surfaces of the one or more wrappers. In addition, or alternatively, particulate sorbent material may be present within the structure of the wrapper material itself.

One of the inner or outer rods may have a higher density relative to the other rod to create a region of controlled pressure drop to control airflow through the smoking article.

The inner rod may comprise a further inner rod of smokeable material

circumscribed by a further inner wrapper, thus forming a triple core co-axial rod. The smoking article may comprise a thread. For example, the smoking article may comprise a rod of smokeable material and the thread may extend

continuously within the smokeable material along the whole length of the rod of smokeable material. The smoking article may comprise a plurality of threads, such as 2, 3, 4, 5, 6, or more threads. The thread or threads may extend along the rod of smokeable material in one or more lateral regions corresponding to the one or more first lateral regions at which, when the smoking article is in use, the target smoke constituent has been found to occur in a higher concentration.

The smoking article may comprise particles that may be concentrated in a longitudinal region extending along the rod of smokeable material. The smoking article may comprise a plurality of lateral regions in which particulate material is concentrated, such as 2, 3, 4, 5, 6, or more regions.

The region or regions of particulate material may extend along the rod of smokeable material in one or more lateral regions corresponding to the one or more first lateral regions at which, when the smoking article is in use, the target smoke constituent has been found to occur in a higher concentration.

The smoking article may comprise both a thread and longitudinally disposed granular material in the same or different one or more lateral regions, targeted to the same or to different smoke constituents.

The smokeable material may be circumscribed by a wrapper and the particles may be adhered to the inner surface of the wrapper. The smokeable material may be circumscribed by a plurality of wrappers, one or more of which may comprise the smoke constituent reducing technology. For example, particulate sorbent material may be adhered to one or more surfaces of one or more of the wrappers, covering the entire surface or surfaces, or present in one or more discrete patches on the surface or surfaces. In addition, or alternatively, particulate sorbent material may be present within the structure of the wrapper material itself.

The smoke constituent reducing technology may be in particulate or granular form. The smoke constituent reducing technology may comprise an additive. The additive may be a sorbent or a catalyst.

The smoke constituent reducing technology may comprise a diluent.

The smoke constituent reducing technology may comprise a smokeable material which in use generates a concentration of the smoke constituent which is lower than the concentration that is produced by tobacco. According to a third aspect, a smoking article is provided. In use, the smoking article generates smoke having a smoke constituent. The smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of the smoke constituent. In use, the smoke constituent is present at a first concentration in one or more first lateral regions of the smoking article. The smoke constituent is present at a second concentration which is lower than the first concentration in one or more second lateral regions of the smoking article. The smoke constituent reducing technology is targeted to reduce the concentration of the smoke constituent present at the one or more first lateral regions.

The smoke constituent reducing technology may be located at the one or more first lateral regions.

The smoke constituent reducing technology may additionally be positioned at the one or more second lateral regions.

The smoking article may comprise a rod of smokeable material, and in this case, the first and second lateral regions may be regions of the rod of smokeable material. The rod of smokeable material may be generally cylindrical in shape and in this case, the first and second lateral regions may be located on a diametrical line across the width of the cylinder. According to a fourth aspect, a smoking article, which is obtainable by the method of the first aspect, is provided.

Brief Description of Drawings

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings (not to scale), in which:

Figure la is a perspective view of a smoking article according to one aspect of the present invention, showing in particular the co-axial construction of the rod of smokeable material, wherein the inner wrapper comprises a smoke constituent reducing additive;

Figure lb is transverse cross-sectional view of the body of the co-axial smoking article of Figure la, showing in particular, the inner wrapper comprising a smoke constituent reducing additive targeted to a lateral region of the rod of smokeable material;

Figure 2a is a perspective view of a smoking article according to one aspect of the present invention, showing in particular, a thread comprising a smoke constituent reducing additive located along a longitudinal axis of a rod of smokeable material;

Figure 2b is transverse cross-sectional view of the body of the smoking article of Figure 2a, showing in particular, a thread comprising a smoke constituent reducing additive targeted to a central lateral region of the rod of smokeable material;

Figure 3a is a perspective view of a smoking article according to one aspect of the present invention, showing in particular, particulate smoke constituent reducing additive located along a longitudinal axis of a rod of smokeable material; Figure 3b is transverse cross-sectional view of the body of the smoking article of Figure 3a, showing in particular, particulate smoke constituent reducing additive targeted to a central lateral region of the rod of smokeable material; Figure 4 shows a number of graphs illustrating gas concentration profiles (%v/v) along the central axis of a cigarette; and,

Figures 5-10 show gas concentration (%v/v) and temperature distributions in a smoking article at different time points.

Detailed Description

As used herein, the term "smoking article" includes smokeable products such as cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat- not-burn products and other devices capable of generating and delivering an aerosol. Such smoking articles may be provided with a filter.

As used herein, the term "smoke constituent" includes any compound that may be found in the smoke produced by the combustion and/or pyrolysis of tobacco.

The smoke arising from a smoking article comprising tobacco is a complex, dynamic mixture of more than 5000 identified compounds. The constituents are present in the mainstream smoke (MS), which exits the mouth end of the cigarette, and are also released between puffs as constituents of sidestream smoke (SS).

Smoking articles such as cigarettes and their formats are often named according to the cigarette length: "regular" (typically in the range 68 -75 mm, e.g. from about 68 mm to about 72 mm), "short" or "mini" (68 mm or less), "king-size" (typically in the range 75 - 91mm, e.g. from about 79 mm to about 88 mm),

"long" or "super-king" (typically in the range 91-105 mm, e.g. from about 94 mm to about 101 mm) and "ultra-long" (typically in the range from about 110 mm to about 121 mm). Cigarettes are also named according to their circumference: "regular" (about 23- 25 mm), "wide" (greater than 25 mm), "slim" (about 22-23 mm), "demi-slim" (about 19-22 mm), "super-slim" (about 16-19 mm), and "micro-slim" (less than about 16 mm). Accordingly, a cigarette in a king-size, super-slim format will, for example, have a length of about 83 mm and a circumference of about 17 mm. Cigarettes in the regular, king-size format, namely with a circumference of from 23 to 25 mm and an overall length of from 75 to 91 mm, are one of many formats commercially manufactured.

Smoking articles may be manufactured in any of the above formats. The smoking article can, for instance, be from 70 to 100mm in length and from 14 to 25mm in circumference. Indeed, the smoking article may have any suitable size and shape as appropriate.

When a smoking article comprising a rod of smokeable material is in use, combustion and/or pyrolysis of the smokeable material may cause the

production of a number of smoke constituents. The concentration at which smoke constituents occur within the burning coal (the burning tip of the cigarette) may differ when the smoking article is used under smouldering versus puffing conditions. When a smoking article is in use the burning portion (burning coal) advances along the rod of smokable material. By inserting a miniature or micro-sampling probe into the smoking article in use, aerosol samples may be withdrawn without influencing the smoking, combustion, and/or pyrolysis processes occurring. In this way, the concentration of a particular smoke constituent at a specific location relative to the burning portion may be determined. By repeating this process using the probe to investigate different specific locations within the smoking article, a map of the concentration of the smoke constituent within the smoking article as it is used may be produced. The concentration of the smoke constituent may be determined as a function of smoking parameters such as the puff volume, puff length, and inter-puff duration. Measurements may be effected relative to a fixed position on the cigarette, such as the burn line.

The concentration of smoke constituents has been found to differ in different lateral regions across the rod of smokeable material. Regions of higher and lower concentration may be located on a diametrical line across the width of the cylindrical rod of smokeable material. As used herein, the "lateral" dimension of a smoking article or a rod of smokeable material refers to any diametric line across the width of a cylindrical rod of smokeable material, wherein the width is measured perpendicularly to the longitudinal axis of the rod.

Inclusion of smoke constituent reducing technology

In accordance with the disclosed method, in order to reduce the concentration of a particular smoke constituent in the smoke produced by a smoking article, the skilled person must first determine the concentration of the smoke constituent at different positions within the smoking article when the smoking article is in use. A smoke constituent reducing technology, which is capable of reducing the concentration of the smoke constituent of interest, may then be incorporated within the smoking article, targeted to reduce the concentration of the smoke constituent at the location at which the smoke constituent has been found to be present at a higher concentration.

This approach has a number of advantages over previous approaches to reducing the concentration of smoke constituents in smoke. By targeting the location of highest concentration, the greatest effect on the concentration of the constituent of interest within the smoke may be most effectively achieved. Moreover, the amount of smoke constituent reducing technology may be reduced because a lower amount of the technology may be used in areas in which the constituent is produced in the lowest concentration, albeit optionally at an inclusion level that effectively reduces the concentration of the smoke constituent in that location.

Also, smoke constituent reducing technologies, which are more effective at reducing a particular smoke constituent, or classes of constituents, in the aerosol, may be selected and positioned within the smoking article to target these constituents. For example, the smoke constituent reducing technologies may be positioned in the region of formation of the smoke constituent.

Positioning a smoke constituent reducing technology within the 'hot zones' of combustion and/or pyrolysis in the smoking article may be kinetically favourable to smoke constituent reducing technologies such as catalysts. The effectiveness of sorbents could also be enhanced in the hot zone, since a target smoke constituent, whilst in the solid or liquid phase at lower temperatures, may occur in the gaseous phase within this zone, and thus be more readily adsorbed. Such technologies, which demonstrate enhanced activity at elevated temperatures, may advantageously be targeted to the hot zones to enhance the removal or destruction of the target smoke constituents.

Conversely, other smoke constituent reducing technologies may operate more effectively at lower temperatures and thus may advantageously be targeted to cooler areas of the smoking article, such as the filter tip.

Since the burning portion advances along the rod as the smoking article is used, the lateral region at which the smoke constituent occurs at a higher

concentration will therefore also advance along the rod of smokeable material. Thus, to optimally target the particular smoke constituent, a smoke constituent reducing technology may be incorporated longitudinally throughout the length of the smoking article at a particular lateral region.

The smoke constituent reducing technology may be incorporated within the rod of smokeable material and/or the filter as appropriate. The smoke constituent reducing technology is targeted to reduce the concentration of a particular smoke constituent at a lateral position corresponding to a position in which the smoke constituent is found in a higher concentration. The smoke constituent reducing technology may be included in the smoking article at the one or more lateral regions at which the smoke constituent has been found to be produced at a higher concentration. The smoke constituent reducing technology may optionally also be included in a lower amount in a lateral region at which the smoke constituent is produced at a lower

concentration.

Location of the smoke constituent reducing technology

The smoke constituent reducing technology may be incorporated within the rod of smokeable material and/or the filter as appropriate. The smoke constituent reducing technology may be located at the one or more first lateral regions at which, in use, the smoke constituent has been found to be present at a higher concentration, relative to the concentration at another region of the smoking article.

The smoke constituent reducing technology may be located in a greater amount at a first lateral region at which, in use, the smoke constituent has been found to be present at a higher concentration, and, in a lesser amount, at a second lateral region at which, in use, the smoke constituent has been found to be present at a lower concentration.

The smoke reducing technology may be located in a region of the smoking article which is away from the one or more first lateral regions at which, in use, the smoke constituent has been found to be present at a higher concentration. In this case, the smoke constituent reducing technology may be targeted to reduce the concentration of the smoke constituent at the one or more first lateral regions at which, in use, the smoke constituent has been found to be present at a higher concentration, relative to the concentration at another region of the smoking article.

The smoke reducing technology may be located in a region of the smoking article which is away from the one or more second lateral regions at which, in use, the smoke constituent has been found to be present at a lower concentration. Several different smoke reducing technologies may be used in a smoking article, positioned in the same or different lateral regions.

It has now been discovered that the incorporation of smoke constituent reducing technologies longitudinally in different lateral positions within a smoking article reduces the level of target smoke constituents generated in use in the smoke.

Depending on the particular smoke constituent reducing technology, the technology may be included in the rod of smokeable material, in the smoking article filter, or in both the rod of smokeable material and the smoking article filter. A number of smoke constituent reducing technologies may only be suitable for incorporation into the filter of the smoking article. Porous polymer resins have been designed for trapping volatile and semivolatile substances from air, for example Tenax TA^®. Other sorbent polymeric resins are available, for example, molecularly imprinted polymers, and commonly used ion exchange or chelating resins, such as Diailon^® CR-20. These materials are unsuitable for use within the smoking material, due to their thermal instability and potential degradation in the 'hot zone' of the smoking article. Smoke constituents

In some embodiments, reductions in mainstream smoke constituents may include, but are not restricted to, one or more of the substances known in the art as 'Hoffmann analytes'. This term relates to a group of constituents of mainstream smoke generated from a smoking article, and includes: aromatic amines; phenols; carbonyls; polycyclic aromatic hydrocarbons; acrylonitrile; volatile hydrocarbons such as isoprene, styrene, benzene, and 1,3-butadiene; nitrogen heterocyclics such as pyridine; quinoline; tobacco specific nitrosamines (TSNAs) such as N'- nitrosoanabasine (NAB), N'- nitrosoanatabine (NAT), 4- (methylnitrosamino)-i-(3-pyridyl)-i-butanone (NNK) and iV'- nitrosonornicotine (NNN); inorganic compounds such as ammonia, hydrogen cyanide, nitric oxide and carbon monoxide; and heavy metals such as mercury, cadmium, lead, chromium and nickel.

The smoke constituents targeted by the smoke constituent reducing technology may include, but are not restricted to, one or a combination of : aromatic amines, such as i-aminonaphthalene, 2-aminonaphthalene, 3-aminobiphenyl, 4- aminobiphenyl; phenols, such as phenol, o-cresol, m-cresol, p-cresol, catechol, resorcinol, hydroquinone; carbonyls, such as formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, methyl ethyl ketone, butyraldehyde; polycyclic aromatic hydrocarbons such as benzo(a)pyrene, naphthalene; aromatic hydrocarbons such as, toluene, benzene; acrylonitrile; volatile hydrocarbons such as isoprene, styrene and 1,3-butadiene; nitrogen heterocyclics such as pyridine, quinoline; tobacco specific nitrosamines (TSNAs) such as N'- nitrosoanabasine (NAB), N'- nitrosoanatabine (NAT), 4- (methylnitrosamino)-i-(3-pyridyl)-i-butanone (NNK) and iV'- nitrosonornicotine (NNN); inorganic compounds such as ammonia, hydrogen cyanide, nitric oxide and carbon monoxide; and heavy metals such as mercury, cadmium, lead, chromium and nickel.

Smoke constituent reducing technologies

The smoke constituent reducing technology may comprise any technology that is capable of being incorporated into a smoking article and reducing the

concentration of a constituent of the smoke produced in use by the smoking article. The smoke constituent reducing technology may be specific for a particular smoke constituent. Alternatively, the smoke constituent reducing technology may have a broad capacity to interact with various smoke

constituents or classes of smoke constituents.

The smoke constituent reducing technology may comprise any technology that is capable of reducing the concentration of a smoke constituent in smoke. For example, the smoke constituent reducing technology may comprise an additive, such as a sorbent or a catalyst, a diluent, or a modified or synthetic smokeable material. By way of examples, a number of suitable smoke constituent reducing technologies are discussed below. Additives

The smoke constituent reducing technology may be a smoke constituent reducing additive. The smoke constituent reducing additive may be any additive that is capable of reducing the concentration of a smoke constituent in smoke. For example, the smoke constituent reducing additive may comprise a sorbent or a catalyst.

The additive may be in any suitable form. For example, the additive may be particulate or in a processed form, such as in the form of a monolith. The smoke constituent reducing technology may be a particulate additive, the particles of which are concentrated in one or more longitudinally extending regions within the filter material or the rod of smokeable material.

The smoke constituent reducing technology may be an additive which is incorporated into one or more of the paper wrappers of the smoking article. The additive may be adhered to one or more surfaces of one or more of the wrappers. The additive may cover the entire surface of one side of the wrapper, or the entire surface of both sides of the wrapper. Alternatively, the additive may be present in one or more discrete patches on the wrapper, which may be on one side of the wrapper, or on both sides of the wrapper. The one or more patch or patches may have any shape or configuration. For example, the patch or patches may be in the form of circumferential bands around the smoking article, or longitudinal stripes along the length of the smoking article. Such wrappers are discussed, for example, in WO 2007/104908.

In addition, or alternatively, particulate additive material may be present within the structure of the wrapper material itself, as described, for example, in WO 2010/043475. For example, the additive may be a particulate sorbent material such as active carbon which is incorporated into the structure of the paper during manufacture of the paper. The sorbent may carry a further smoke constituent reducing technology, for example, the sorbent may be impregnated with a diluent, and/or the sorbent may serve as a carrier for a catalyst.

The wrapper material may be a paper material. Alternatively, the wrapper may comprise a reconstituted tobacco material. The reconstituted tobacco material may comprise particulate additive material. The additive may be applied to the reconstituted tobacco material using the same approaches as described above in respect of paper wrappers. For example, the additive may be applied to the surface of the material, and/or the additive may be incorporated within the structure of the reconstituted tobacco material itself. Such a material is described, for example, in WO 99/38396.

The additive may be adhered to one or more threads which extend longitudinally along the length of the smoking article filter and/or rod of smokeable material. Such threads are described, for example, in WO 96/14762, WO 2009/010380,

The smoke constituent reducing additive may be coated or otherwise contained in a protective environment to prolong shelf life. For example, the smoke constituent reducing additive may comprise an encapsulated additive. The protective environment utilised to prolong shelf life of the smoke constituent reducing additive should not inhibit the activity of the material, which may be capable of being released or activated by mechanisms encountered during the smoking process. For example, the additive may be activated by heat or by interaction with a smoke constituent such as water.

Sorbents

A "sorbent" is a substance that can condense or hold molecules of other substances on its surface, and/or can take up other substances, i.e., through penetration of the other substances into its inner structure, or into its pores. Accordingly, the term "sorbent" as used herein refers to an adsorbent, an absorbent, or a substance that can function as both an adsorbent and an absorbent. The sorbent may be any relatively high surface area material to which the smoke constituent may adsorb, and which is thereby capable of reducing the concentration of a smoke constituent in smoke.

The smoke constituent reducing additive may include one or a combination of any suitable sorbents, including, for example, carbon (such as activated carbon), zeolite, silica gel, silica, silicates, alumino-silicates, sepiolite, clay, aluminium oxide.

In particular, the smoke constituent reducing additive may be an activated carbon material. The activated carbon material may be derived from vegetable matter (such as coconut shells), as described, for example, in WO 2012/032349. Alternatively, the activated carbon material may be derived from a resin (such as a phenolic resin), for example, as described in WO 2006/103404.

The activated carbon material may be surface modified to improve the specificity of the material for a particular smoke constituent or class of smoke constituents. The presence of particular chemical groups on the surface of the porous carbon material may affect the adsorption properties of the material. For example, activated carbon material prepared using a nitrogen-donating agent may enhance the selective adsorption of smoke constituents including low molecular weight aldehydes and HCN, as described in WO 2012/098405. Likewise, activated carbon material prepared using magnesium carbonate may enhance the selective adsorption of acrolein, formaldehyde and HCN, as described in WO 2012/160354. The hydrophobicity and/or hydrophilicity of the surface of the sorbent material may be modified to provide further control of the sorbent properties and improve the specificity of the material for a particular smoke constituent or class of smoke constituents. The sorbent may comprise micropores (<2nm pore diameter), mesopores (2- 50nm diameter), and/or macropores (diameters greater than 50nm). The sorbent may be modified to adjust the pore structure, such as to increase the mesoporosity, as described, for example, in WO 2010/103323 and WO

The sorbent may be present in the smoking article in granular or particulate form, for example, as described in WO 2006/103404.

The sorbent may be a carbonaceous dried gel, for example of the type described in WO 2011/030151. Such dried gels are porous, solid-state materials obtained from gels or sol-gels whose liquid component has been removed and replaced with a gas, which have then been pyrolysed and/or carbonized. They can be classified according to the manner of drying and include carbon xerogels, aerogels and cryogels.

Xerogels are typically formed using an evaporative drying stage under ambient pressure conditions. They generally have a monolithic internal structure, resembling a rigid, low density foam having, for example, 60-90 % air by volume. Aerogels, on the other hand, can be produced using other methods such as supercritical drying. They contract less than xerogels during the drying stage and so tend to have an even lower density (90-99 % air by volume for example). Cryogels may be produced using freeze drying techniques.

The sorbent may comprise carbon material in the form of carbon nanotubes and/or graphene.

The sorbent may comprise a Metal Organic Framework (MOF).

The sorbent may be coated. For example, the sorbent may comprise an alginate- coated porous carbon material. In addition, or alternatively, the sorbent may carry a diluent, for example as described in WO 2010/125386. The sorbent may be in a processed form. In particular, the sorbent may be in the form of a monolith, for example as described in WO 2012/168699. The sorbent may comprise an adsorption promoter. A suitable adsorption promoter may comprise a hydrophilic organic substance and both a hydrogen bond donor and acceptor. Such an adsorption promoter may increase the affinity of the sorbent for phenol, as discussed in WO 2011/015861. Catalysts

The smoke constituent reducing additive may be a catalyst. A "catalyst" is a substance that modifies and increases the rate of a chemical reaction without being consumed in the process. The catalyst may be capable of promoting the conversion of a smoke constituent into one or more different substances. In addition, or alternatively, the catalyst may convert a compound, which would otherwise be a precursor of the target smoke constituent, into an alternative compound, thus preventing the formation of the smoke constituent.

Catalysts may comprise, for example, metals, such as transition metals or rare earth metals, metal salts, or metal oxides. In some embodiments, a catalyst capable of facilitating the oxidation of CO to C0₂ may be used. Suitable CO catalysts include metals, such as transition metals or rare earth metals, metal salts, metal oxides or combinations thereof. In particular, a catalyst capable of facilitating the oxidation of CO to C0₂ may comprise iron oxide and/or a hopcalite (copper manganese oxide).

The catalyst may be placed on a support or carrier made of graphite, activated carbon, copper oxide, alumina or titania, for example. The carrier may be uniformly coated with the catalyst, the loading being from about 0.1% to about 10%, based on the total dry weight of the coated support or carrier.

The catalyst may be provided in the form of coarse, fine or ultrafine particles. Coarse particles are particles having a diameter of about 2.5μπι to about 200μπι. Fine particles are particles having a diameter of about loonm to about 2.5μπι. Ultrafine particles are particles having a diameter of less than about loonm. Typically, the particles have an average particle size of between about inm and ιοομηι, for example, between about lonm to about ιομπι. Particles of catalyst may be obtained commercially.

Molecularly imprinted polymers

The additive may comprise a molecularly imprinted polymer (MIP).

The MIP may be specific for one or more than smoke constituents. For example the MIP may be capable of specifically binding tobacco specific nitrosamines, as described, for example, in WO 2008/068153.

Diluents

The smoke constituent reducing technology may comprise a diluent. A "diluent" acts as a direct replacement of a smoke constituent, and thereby reduces the concentration of the smoke constituent in the smoke.

The diluent may be included in the smokeable material. For example, the diluent may be bound to the smokeable material and/or incorporated within the cellular structure of the material, as described in WO 03/092416 and WO 2012/010880. The diluent may be incorporated into the wrapper of the smokeable material. For example, the diluent may be carried by a sorbent material which is incorporated into the wrapper. Such wrappers are described, for example, in WO

The diluent may be impregnated into particulate porous material, as described, for example, in WO 2010/125386.

The diluent may be in the form of particles of diluent encapsulated with a barrier material, as discussed, for example, in WO 2010/125385.

Suitable diluents include aerosol forming means utilising a wide range of classes of substances known to those skilled in the art. For example, polyhydric alcohols, such as glycerol, propylene glycol, sorbitol and triethylene glycol; esters, such as diacetin, triethyl citrate, isopropyl myristate or triacetin, high boiling point hydrocarbons, or lactic acid. A combination of diluents may be used, in equal or differing proportions. Other additives

The smoke constituent reducing technology may comprise a chemical reactant which may reduce the concentration of a smoke constituent by reacting with the constituent. The reaction mechanism may comprise a chemical combination and/or a chemical combination followed by a decomposition.

The smoke constituent reducing technology may comprise an additive which adjusts the temperature of combustion of the smokeable material.

For example, the additive may act to either decrease the thermal energy produced during the smoking process by passively absorbing energy, or it may actively influence smoking thermal energy by itself undergoing an endothermic promoted change (wherein thermal energy may be taken out of the smoking process) or an exothermic promoted change (wherein thermal energy may be contributed to the smoking process). In this way, due to the adjusted

temperature, the chemical reactions occurring as the smokeable material combusts or pyrolyses may be adjusted, and different smoke constituents may be produced, and as a result, the concentration of target smoke constituents, or classes of constituents, may be reduced.

An example of a material that may be used to increase the temperature is a carbon material such as particulate charcoal material. Similarly, other additives may be used to change the conditions within the smokeable material and thus adjust the chemical reactions occurring. Suitable examples may include oxidising and reducing agents.

Ceramic wrapper materials

The smoke constituent reducing technology may comprise a ceramic-based wrapper. The ceramic-based wrapper may be capable of trapping smoke constituents. In addition, or alternatively, the ceramic-based wrapper may be thicker than a conventional wrapper and thus displace a proportion of the smokeable material. Ceramic-based wrappers are discussed, for example, in WO OI/4159O. The ceramic-based wrapper may comprise a smoke constituent reducing additive which is capable of reducing the concentration of a smoke constituent in smoke. The additive may be incorporated together with the ceramic filler into the structure of the wrapper. In addition, or alternatively, the additive may be applied to the surface of the wrapper.

The ceramic-based wrapper may comprise a proportion of a ceramic filler of predefined shape, a binder, optionally a burn additive and optionally an ash improver.

The predefined shape of the ceramic filler is such that the wrapper has a porous self-sustaining structure and when combusted the wrapper loses its structural integrity. For example, the ceramic filler may be spherical or substantially spherical, oval or substantially oval, or another irregular shape approximating thereto.

Advantageously the ceramic filler has a particle size in the range of 2-9θμπι, more preferably 2-75μπι and even more preferably 25-7θμπι, such as about 5_θμπι.

The ceramic filler may be an insoluble or low solubility metal oxide or metal salt, and may be a thermally stable metal oxide or metal salt. The ceramic filler may be one or more of alumina, silica, an alumino-silicate, silicon carbide, stabilised or un-stabilised zirconium oxide, zircon, garnet, feldspar, or other materials known to the skilled man and having the necessary particle size or other suitable ceramic materials having been milled to the necessary size or shape.

The ceramic filler may be present at greater than 40% by weight of the dry materials in the slurry producing the wrapper, and is more preferably present in the range of 50-95%, and more preferably 70-90%.

The binder functions to cement the particles of ceramic filler together. The binder may be an organic binder, and may be one or more of an alginate, (such as calcium alginate or propylene glycol alginate), a gum, a cellulose (modified or natural), a pectin or pectinaceous binder, starch, or the Group I or II metal salts of these binders, such as sodium carboxymethyl cellulose or sodium alginate. In addition or alternatively, the binder may be an inorganic binder, and may be one or more of activated alumina, aluminium silicate, magnesium silicate or an inert clay. A burn additive may be included in the ceramic-based wrapper to improve the burn characteristics of the wrapper. The burn additive may be present in the range of 1-15% by weight of the dry materials in the slurry used to produce the wrapper and is more preferably < io% and even more preferably <5%, such as in the range of 2-5%. The burn additive is a burn promoter. Suitable burn additives may be selected from one or more of salts of Group I or II metals such as acetates, citrates and other burn promoters known to the skilled person.

An ash improver may be included in the ceramic-based wrapper to provide bridging means or packing improvement means between the ceramic filler particles. The wrapper should burn down and ash in a manner similar to that of a conventional combustible smoking article. The components of the wrapper, and in particular the ceramic filler and ash improver, have a particle size and/or shape such that their combination provides the necessary strength in the wrapper before combustion but loses such strength during combustion in order to provide acceptable ashing of the combusted products.

The inorganic ash improver suitably has a platelet morphology and materials that have the appropriate platelet morphology compared to the more rounded shape of the ceramic filler, include one or more of mica, chalk, perlite, clays, such as, for example, vermiculite; kaolinites and talcs. The ash improver may in addition or alternatively be a material with a very small particle size such that particles thereof bridge the voids between the larger ceramic filler particles.

In some embodiments, the ceramic-based wrapper may be produced using known manufacturing techniques. In particular, ceramic-based wrappers may be formed by producing a thick slurry of the wrapper components, coating the slurry about a rotating mandrel, and removing excess moisture by physical or chemical means. Alternatively, the slurry may be cast as a sheet on a drum or band caster, or extruded as a hollow tube, through a "torpedo" die-head, for example, which has a solid central section, or extruded as a sheet material. The ceramic-based wrapper may have a thickness of o.i-4mm, and may preferably be 1.5-3.5mm, such as 2.1-2.8mm in thickness.

Smokeable materials

The smoke constituent reducing technology may comprise the use of an alternative or modified smokeable material. For example, some smokeable materials may generate lower amounts of a smoke constituent than others and the smoke constituent reducing technology may comprise a smokeable material that is known to generate a low amount of a particular smoke constituent. Thus, a smokeable material that is known to generate a low amount of a smoke constituent may be incorporated into specific lateral regions of a rod of smokeable material. Smokeable materials, including tobacco and tobacco reconstituted materials, and tobacco-free materials, which generate low amounts of a smoke constituent, may be used.

The smoke constituent reducing technology may comprise a modified tobacco material. The tobacco may be modified to reduce the amount of smoke constituent produced upon combustion or pyrolysis of the tobacco. The tobacco may be modified by addition of modifying agents. For example, salts such as inorganic salts may be added to tobacco to alter the type and concentrations of smoke constituents produced upon combustion or pyrolysis of the material. Suitable metal salts include zinc chloride and magnesium chloride.

The tobacco may be modified by the addition of smoke diluents on its surface and/or within its cellular structure, as described for example in WO

2012/010880. The tobacco may comprise a diluent and be coated with a barrier material, as described for example, in WO 2010/125287.

The smoke constituent reducing technology may comprise a tobacco substitute material such as a smokeable filler material. The smokeable filler material may comprise no tobacco, and may comprise for example, a filler such as chalk, and a binder. The smokeable filler material may be a foamed smokeable filler material. Such a material is described, for example, in WO 2005/044026. The smoke constituent reducing technology may comprise a smokeable material such as tobacco that is heated to cause the volatilisation of the low boiling point components but avoiding pyrolysis or combustion of the material or volatiles, and thereby reducing the concentration of smoke constituents.

Materials comprising no tobacco, such as chalk particles bound together with a suitable binder such as sodium alginate to form a sheet or extrudate, which may be subsequently cut or shredded may also be used as a smoke constituent reducing technology. These materials may also contain other ingredients which act as aerosol forming substances that are released on combustion or by thermal means. Such sheets are described, for example, in WO 03/092416.

The smoke constituent reducing technology may be added to, and/or carried by, a smokeable element comprising a porous material such as a porous carbon material. The technology may be carried within the pores of the porous material and may be released or activated when the smoking article is in use. The technology may be released by any suitable means, for example, the temperature, pH, moisture content, or other property of the smoke or combustion of the smokeable material may induce the release and/or activation of the technology. Such a material is described, for example, in WO 2013/045944. Any of the smoke constituent reducing technologies may be used in combination with another smokeable material, which may be another smoke constituent reducing technology.

The smokable material may comprise tobacco material. The tobacco material may comprise one or more of stem, lamina, and tobacco dust. The tobacco material may comprise one or more of the following types: Virginia or flue-cured tobacco, Burley tobacco, Oriental tobacco, reconstituted tobacco, and expanded tobacco. The smokable material may comprise a blend of tobacco material, and may, for example, comprise Virginia tobacco, Burley tobacco, Oriental tobacco, reconstituted tobacco, expanded tobacco, such as dry ice expanded tobacco, and stem. The smokable material may comprise processed tobacco materials, such as volume expanded or puffed tobacco, processed tobacco stems, such as cut-rolled or cut-puffed stems, reconstituted tobacco materials, blends thereof, and the like. The smokable material may comprise a humectant. The humectant may comprise, for example, glycerol, tri ethylene glycol and/or propylene glycol.

The smokable material may further comprise a colourant and/or a flavourant. As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers. The colourant may be used to darken the material and the flavourant may be used to impart a particular flavour. Finely ground, granulated or homogenised tobacco may be used. Industry approved food colourants may also be used, such as Eisoa (caramel), E151 (brilliant black BN), E153 vegetable carbon or E155 (brown HT). Suitable flavourants include menthol and vanillin, for example.

Control of smoke flow

The smoking article may be configured such that different internal regions offer different levels of resistance to the passage of smoke, thereby providing different levels of pressure drop in the different regions. This may be achieved for example, by the use of different smokeable materials, having different inherent densities, or different packing densities, in different regions of the smoking article. In use, a greater pressure drop will be established as smoke is drawn through the region of higher density, as described, for example, in WO

It may be advantageous to arrange smoking articles in this way because smoke that is drawn through the region of greater pressure drop may move more slowly and therefore may be subject to an increased action from the smoke constituent reducing technology within that region. This may be particularly effective in embodiments in which the smoke constituent reducing technology comprises an additive such as a sorbent or a catalyst.

Furthermore, different combinations of smoke constituents may be produced under different pressures. Thus, the use of compartments having different pressure drops may directly reduce the level of production of the smoke constituent. Specific embodiments

A description of a suitable methodology to determine distribution concentrations of smoke constituents with respect to lateral and longitudinal regions of a smoking article is given in the Examples.

The concentration of smoke constituents can be measured by inserting a miniature or micro-sampling probe into the smoking article at known spatial positions. Smoke samples may then be collected without influencing the smoking, combustion, and/or pyrolysis processes that are occurring as the smoking article is used. The concentration of smoke constituents may thus be determined in real time, for example, by mass spectrometry as described in the Examples.

Smoke constituents have been found to be produced at different concentrations in different regions of the smoking article when the smoking article is in use. In accordance with the disclosed method, a smoke constituent reducing technology, which is capable of reducing the concentration of the smoke constituent, is targeted to reduce the concentration of the smoke constituent present at the one or more first lateral regions. For example, the smoke constituent reducing technology may be incorporated within the smoking article at a lateral position corresponding to the location at which the smoke constituent has been found to be present at a higher concentration relative to the concentration at another lateral region. The smoke constituent reducing technology may be incorporated into a smoking article using any suitable method. A number of approaches, which have been found to be suitable, are shown in the accompanying Figures and discussed below. Figure la, lb is a schematic illustration of a smoking article 101 according to an embodiment of the invention.

In the embodiment shown in Figure la, lb, the smoke constituent reducing technology is targeted to a lateral region, which is an intermediate annular region, located between the centre and the circumferential surface of the rod of smokeable material. Figure la, lb shows a smoking article 101 comprising a filter 102 and a rod of smokeable material 103. The filter 102 is at the mouth end of the smoking article 101. The rod of smokeable material 103 is in the form of a cylindrical rod, and the circumferential surface of the smokeable material 103 is wrapped in a wrapping material 104, such as a cigarette paper.

The filter 102 comprises a substantially cylindrical plug of filter material 105 wrapped in a plugwrap 106 around its circumferential surface. The wrapped rod of smokeable material 103 is aligned with the filter 102, such that the end of the rod of smokeable material abuts the end of the filter 102. The rod of smokeable material 103 is j oined to the filter 102 by tipping material 107 which overlays the filter 102 and partially overlays the wrapping material 104. In the embodiment shown, the smoke constituent reducing technology 109 is located within the rod of smokeable material 103. In other embodiments, a smoke constituent reducing technology, which may be the same or a different technology, may in addition or alternatively be located within the filter 102 of the smoking article 101.

The rod of smokeable material 103 is of co-axial construction and has an inner rod 110, an inner wrapper 111, and an outer rod 112. The outer rod is wrapped in the wrapping material 104. The inner rod 110 of the co-axial arrangement contains a first smokeable material 114, which in the embodiment shown is cut tobacco material, and may in general comprise any suitable smokeable material or blend.

The inner rod 110 is circumscribed by the inner wrapper 111, as shown in Figure ia, lb. The inner wrapper 111 is, in the present example, a cigarette paper.

The inner rod 110 and inner wrapper 111 are circumscribed by the outer rod 112, as shown in Figure ia, lb. In the embodiment shown, the outer rod 112

comprises a second smokeable material 115, comprising cut tobacco material, which is combusted during use. The second smokeable material 115 may in general comprise any suitable smokeable material or blend. As shown in Figure la, lb, the outer rod 112 is circumscribed by the outer wrapper 104. In the embodiment shown, the outer wrapper 104 is a cigarette paper.

The construction of the inner rod 110, inner wrapper 111, outer rod 112 and outer wrapper 104, may for example, be achieved through existing co-axial cigarette manufacturing technology. In use, combustion of the inner and outer rods 110, 112 generates smoke which is drawn through the smoking article 101.

The rod of smokeable material comprises a smoke constituent reducing technology 109 which is capable of reducing the concentration of a particular target smoke constituent in smoke. In other embodiments, the smoke

constituent reducing technology may be capable of reducing the concentration of several target smoke constituents.

In the embodiment shown in Figure la, lb, the smoke constituent reducing technology comprises particles of a smoke constituent reducing additive 109. The additive 109 is capable of adsorbing a target smoke constituent from smoke.

Specifically, the inner wrapper 111 comprises a smoke constituent reducing additive 109, as shown in Figure lb. In this case, the additive is particulate activated carbon material, and is adhered to, and completely covers, both surfaces of the wrapper 111. Due to being adhered to the inner wrapper 111, the additive 109 is targeted to a position within the rod of smokeable material 103 corresponding to an intermediate annular region. The targeted region may be varied by adjusting the position of the inner wrapper 111, for example, by adjusting the relative diameters of the inner and outer rods 110, 112.

In the embodiment shown, the additive 109 is adhered to the wrapper 111 as described in WO 2007/ 104908 and is present on both faces of the inner wrapper 111. Any suitable method may be used to apply the additive to the wrapper 111. In other embodiments, the additive 109 may in addition, or alternatively, be incorporated within the structure of the wrapper m, as described in WO

The inner wrapper 111 is a paper wrapper material. In other embodiments, however, the wrapper 111 may comprise an alternative material, such as a reconstituted tobacco material, which may comprise particulate sorbent material as described in WO 99/38396.

By means of the arrangement shown in Figure 1, a smoke constituent reducing additive may be targeted to specific lateral regions with the rod of smokeable material 103. Specifically, the inner and outer rods 110, 112, may be constructed so that the inner wrapper 111 substantially coincides with the lateral regions at which a particular smoke constituent has been found to occur at a concentration which is higher than the concentration found in another lateral region.

In use, combustion of the rod of smokeable material 103 generates smoke which is drawn through the smoking article 101. Due to the targeted positioning of the smoke constituent reducing additive 109 within the smoking article 101, the concentration in the smoke of a particular smoke constituent, which has previously been found to be produced at a high concentration in the lateral region of the smokeable material 103 targeted by the inner wrapper 111, may be reduced.

In some embodiments, the inner wrapper 111 may comprise reconstituted tobacco sheet material. The reconstituted tobacco sheet material may have a similar thickness to a paper wrapper, or may be of a different thickness, such as, for example, thicker. In embodiments in which the wrapper is thicker than a paper wrapper, the reconstituted tobacco sheet material 111 may function as a smoke constituent reducing technology by displacing a proportion of the first and/or second smokeable material 114, 115. In addition, or alternatively, due to the composition of the reconstituted tobacco sheet material 111, the material may produce a reduced amount of the smoke constituent when combusted or pyrolysed. For example, the reconstituted tobacco sheet material may comprise a sorbent, as described in WO 99/38396. The wrapper may also be modified in other ways in order to reduce the concentration of a specific smoke constituent. For example, the wrapper may comprise a diluent, as described in WO 2010/043475. The inner rod wrapper 111 may be permeable to smoke and smoke constituents, or may be impermeable, and may prevent the passage of smoke and smoke constituents.

In some embodiments, for example, where it is desired to target smoke constituents in other lateral regions of the smoking article, the smokeable material of the inner rod 110 and/or outer rod 112 may comprise a smoke constituent reducing technology.

For example, in some embodiments, in addition to, or as an alternative to being applied to one or more faces of the inner wrapper 111, or dispersed throughout the body of the wrapper material, the additive 109 may be applied to the smokeable material 114, 115 of the inner and/or outer rod 110, 112. The additive may be bound to the smokeable material or simply distributed within the smokeable material, for example, as described in WO 2011/033121. In these embodiments, the inner wrapper 111 may serve to segregate lateral regions of the rod of smokeable material, wherein different lateral regions may comprise different concentrations of additive 109.

In addition, or alternatively, the inner rod 110 and/or outer rod 112 may comprise different smokeable materials or different blends of smokeable material. Upon combustion, the different smokeable materials in the inner and outer rods 110, 112, may give rise to different quantities of a particular smoke constituent. One or both of the smokeable materials 110, 112, may comprise a smoke constituent reducing technology, which may be selected to produce a lower concentration of the particular target smoke constituent. In addition, or alternatively, a smoke constituent reducing additive 109 may be applied to one or both of the different smokeable materials.

For example, in some embodiments, the inner rod 110 may comprise one or more tobacco substitute materials such as a smokeable filler material. Such tobacco substitute materials may in use generate reduced levels of a target smoke constituent and may thereby constitute a tobacco constituent reducing technology, which is targeted to a lateral region which is a central region of the smoking article, by means of the co-axial construction of the rod of smokeable material.

In other embodiments, the outer rod 112 may in addition, or alternatively, contain one or more tobacco substitute materials such as a smokeable filler material. Such tobacco substitute materials may in use generate reduced levels of a target smoke constituent and may thereby constitute a tobacco constituent reducing technology, which is targeted to a peripheral lateral region by means of the co-axial construction of the rod of smokeable material.

The smokeable filler materials that may be used in the inner rod 110 and/or outer rod 112 may comprise an inorganic filler, such as described in WO

03/092416. The smokeable filler material may in addition, or alternatively, be a foamed smokeable filler material, such as described in WO 2005/044026.

The inner or outer rod 110, 112 may comprise a smokeable material other than tobacco or a tobacco substitute material. For example, the smokeable material of the inner or outer rod 110, 112 may comprise a smokeable element. A suitable smokeable element may comprise particles of a porous carrier material, bound together by means of a binder, wherein the binder is a combustible binder. The smokeable element may further comprise an agent, which may be a flavourant, such as a tobacco extract, carried by the porous carrier material. Such a smokeable element is described in WO 2013/045944.

In addition, or alternatively, the smoking article 101 may be arranged such the first or second smokeable material is heated to cause volatilisation of low boiling point components within the smokeable material, while avoiding pyrolysis or combustion of the smokeable material or volatile smokeable material

constituents. Such an arrangement is described, for example in WO

To improve the targeting of the smoke constituent reducing technology to the one or more lateral regions at which the particular smoke constituent is concentrated, the inner rod 110 may be symmetrical or asymmetrical. For example, in cross-section, the inner rod no may be circular, or may have any non-circular shape, such as for example, oval, square, rectangular, or triangular. In addition, or alternatively, the inner rod no may be positioned off-centred within the outer rod 112, such that the longitudinal axes of the two rods 110, 112 do not coincide.

In some embodiments, the inner rod 110 comprises one or more further inner rod(s). In this way, smoke constituent reducing technologies can be targeted towards an increased number of lateral locations within the smoking article.

In some embodiments, the smoking article is configured such that the inner and outer rods 110, 112, offer different levels of resistance to the passage of smoke. Thus, there are different levels of pressure drop in the different compartments. This may be achieved for example, by constructing one of the inner and outer rods at a higher density than the other rod. This will create a (greater) pressure drop in the rod of higher density. Smoke drawn through the compartment which has a greater pressure drop may move more slowly and therefore may be subject to an increased action from the smoke constituent reducing technology within that compartment. This may be particularly effective in embodiments in which the smoke constituent reducing technology comprises an additive such as a sorbent or a catalyst.

Furthermore, different combinations of smoke constituents may be produced under different pressures. Thus, the use of compartments having different pressure drops may directly reduce the level of production of the smoke constituent.

In some embodiments, the outer wrapper 104 may comprise the smoke constituent reducing technology. This may be in addition, or as an alternative, to the use of a smoke constituent reducing technology in the first and/or second smokeable materials 114, 115, and/or the inner wrapper 111. Such an

arrangement may be particularly suitable for targeting smoke constituents that have been found to be produced at a higher concentration in peripheral regions, nearer to the circumferential surface of the outer wrapper 104 of the smoking article 101. For example, the outer wrapper 104 may comprise a smoke constituent reducing technology in the form of an additive, such as a sorbent or a catalyst, adhered to the inner face of the wrapper 104, such as described in WO 2007/104908. In addition, or alternatively, the outer wrapper 104 may comprise reconstituted tobacco sheet material, as described above in respect of the inner wrapper 111, and in WO 99/38396.

In some embodiments the smoking article 101 may comprise a ceramic-based wrapper, such as described in WO 01/41590. The ceramic-based wrapper may be capable of trapping smoke constituents. In addition, or alternatively, the ceramic-based wrapper may be thicker than a conventional wrapper and thus displace or replace a proportion of the second smokeable material 115.

In some embodiments, the ceramic-based wrapper may comprise a smoke constituent reducing additive which is capable of reducing the concentration of a smoke constituent in smoke. In some embodiments, the additive may be incorporated together with the ceramic filler into the structure of the wrapper. In addition, or alternatively, the additive may be applied to the surface of the wrapper 104.

In accordance with embodiments of the type shown in Figure la, lb, the arrangement of two or more smoke constituent reducing technologies, which may be the same or different technologies, at two or more lateral positions in the smoking article may be used to facilitate reductions of smoke constituents at lateral positions where smoke constituents may be generated at both higher and lower concentrations. Specifically, the arrangement of the co-axial smoking article shown in Figure 1 allows the accurate incorporation of one or more different smoke constituent reducing technologies into specific location(s) in the smoking article. For example, as described above, the inner and/or outer wrappers 111, 104, and/or the first and/or second smokeable material 114, 115, or any combination of these parts, may comprise one or more smoke constituent reducing technologies. The location of the technologies may be easily and accurately controlled, by adjusting the materials used and the diameter of the inner rod 110, to target one or more smoke constituents based on prior measurements of the concentration of the smoke constituents present at different locations when the smoking article is in use. Figure 2a, 2b is a schematic illustration of a smoking article 201 according to a further embodiment of the invention. Corresponding reference numerals are used for features of the smoking article 201 which are the same as those of the smoking article 101 described with reference to Figure 1, unless otherwise stated below.

As shown in Figure 2a, 2b the smoking article 201 includes a filter 202 and a rod of smokeable material 203.

In the embodiment shown in Figure 2a, 2b, the smoke constituent reducing technology is targeted to a lateral region, which is a central region of the smoking article. The filter 202 comprises a substantially cylindrical plug of filter material 205 wrapped in a plugwrap 206 around its circumferential surface. The rod of smokeable material 203 is wrapped in a wrapping material 204. The rod of smokeable material 203 is connected longitudinally to the filter 202 by tipping material 207 overlaying the filter 202 and partially overlaying the wrapping material 204.

The rod of smokeable material 203 is circumscribed by a wrapping material 204, as shown in Figure 2a, 2b. The wrapping material 204 may be a cigarette paper. The rod of smokeable material 203 is connected longitudinally to the filter 202 by tipping material overlaying the filter 202 and partially overlaying the wrapping material 204.

The rod of smokeable material 203 comprises a smokeable material, in this case tobacco 208. The smokeable material 208 may in general comprise any suitable smokeable material or blend.

The rod of smokeable material 203 also comprises a smoke constituent reducing technology 209, which is capable of reducing the concentration of a smoke constituent in smoke. In the embodiment shown, the tobacco rod 203 comprises a smoke constituent reducing technology in the form of a thread 210 disposed within the tobacco material 208. The thread and its method of incorporation may be similar to that described in WO 96/14762 and WO 2010/032032.

The thread 210 is positioned along a central longitudinal axis of the rod 203.

The thread 210 extends continuously the whole length of the rod. In the embodiment shown, the thread 210 comprises carbon in fibrous form, such as carbon fibre or carbonised fibre materials, for example, carbonised polyester or polyamide, such as described in WO 96/14762.

The carbon fibre threads 210 are generally used as a continuous strand so as to be easily incorporable into the tobacco rod 203 as part of a continuous manufacturing operation.

The thread 210 may comprise a loosely assembled bundle or strand of typically 1 to 30 micrometres diameter or larger.

The presence of the carbon fibre thread 210 may itself reduce the concentration of the smoke constituent, but the thread may also be used as a carrier, for example of a smoke constituent reducing technology 209. Any suitable smoke constituent reducing technology 209 may be carried by the thread 210. For example, an additive 209 may be used, which may be a sorbent such as, for example, particulate activated carbon material, or a catalyst such as a metal catalyst. Metals which are suitable for plating onto the thread 210 include, in successive layers, first copper then silver; copper then gold; copper, silver then gold; copper, silver then platinum; copper, silver, gold then platinum or other suitable metals such as tin. Any other suitable metal or combination of metals may be used.

The additive 209 may be applied to the thread 210 by any suitable method. The smoke constituent reducing technology may be retained both by surface adsorption on the thread material and by interstitial retention between the fibres of the bundle.

The additive 209 is capable of adsorbing a particular target smoke constituent from smoke. The thread is positioned longitudinally along the centre of the smokeable material 208, and in this way, the additive 209 is targeted to a position within the rod of smokeable material 203 corresponding to the central lateral region of the smoking article. Smoking articles having this configuration may therefore be suitable for use when the target smoke constituent has been found to be present in a higher concentration in a central lateral region of the smoking article versus another lateral region.

When the smoking article 201 of Figure 2 is in use, combustion of the rod of smokeable material 203 generates smoke which is drawn through the smoking article 201. The smoke constituent may be produced at a higher concentration in the central lateral region and due to the targeted positioning of the smoke constituent reducing additive 209 the concentration of the smoke constituent may be reduced. The targeted region may be varied by adjusting the position of the thread 210 within the smokeable material 208. For example, where the smoke constituent has been found to be present at a higher concentration in a non-central lateral position, the thread 210 may be positioned extending longitudinally in a non- central lateral region of the tobacco rod 203. For example, the rod of smokeable material 203 may comprise one or more threads in a peripheral lateral region of the rod of smokeable material 203.

In other embodiments, for example where the smoke constituent has been found to be present at a higher concentration in more than one lateral position, the thread 210 may be positioned extending longitudinally in more than one lateral regions of the tobacco rod 203. For example, the rod of smokeable material may comprise one or more threads extending longitudinally along two, three, or four lateral regions of the rod 203. The plurality of threads may comprise different additives 209, targeted towards the same or different smoke constituents. By means of the arrangement shown in Figure 2, a smoke constituent reducing additive 209, 210 may be targeted to one or more specific lateral regions within the rod of smokeable material 203. Specifically, the position of the thread or threads 210 within the smokeable material 208 may be arranged to

substantially coincide with the lateral regions at which a smoke constituent has been found to occur at a higher concentration.

The arrangement of a plurality of smoke constituent reducing threads at several lateral positions in the requisite quantities, may be used to facilitate reductions of smoke constituents at lateral positions where smoke constituents may be generated at both higher and lower concentrations, hence further lowering smoke constituent concentrations generated at these positions.

In some embodiments, one or more threads may be used in combination with other smoke constituent reducing technologies as appropriate. For example, the wrapper 204 may be a wrapper comprising a smoke constituent reducing technology as described above in respect of the embodiment of Figure la, lb.

In accordance with embodiments of the type shown in Figure 2a, 2b, the arrangement of two or more smoke constituent reducing technologies, which may be the same or different technologies, at two or more lateral positions in the smoking article may be used to facilitate reductions of smoke constituents at lateral positions where smoke constituents may be generated at both higher and lower concentrations. Specifically, the arrangement of the smoking article shown in Figure 2 allows the accurate incorporation of one or more different smoke constituent reducing technologies into specific location(s) in the smoking article. For example, as described above, the one or more threads 210, the content of the smokeable material 208, and the wrapper 204, or any combination of these parts, may comprise one or more smoke constituent reducing technologies. The location of the technologies may be easily and accurately controlled, by adjusting the materials used and the position and number of threads 210, to target one or more smoke constituents based on prior measurements of the concentration of the smoke constituents present at different locations when the smoking article is in use. Figure 3a, 3b is a schematic illustration of a smoking article 301 according to a further embodiment of the invention. Corresponding reference numerals are used for features of the smoking article 301 which are the same as those of the smoking article 101 described with reference to Figure 1, unless otherwise stated below.

As shown in Figure 3a, 3b the smoking article 301 includes a filter 302 and a rod of smokeable material 303. In the embodiment shown in Figure 3a, 3b, the smoke constituent reducing technology is targeted to a lateral region, which is a central region of the smoking article.

The filter 302 comprises a substantially cylindrical plug of filter material 305 wrapped in a plugwrap 306 around its circumferential surface. The rod of smokeable material 303 is wrapped in a wrapping material 304. The rod of smokeable material 303 is connected longitudinally to the filter 302 by tipping material 307 overlaying the filter 302 and partially overlaying the wrapping material 304.

The rod of smokeable material 303 comprises a smokeable material, in this case tobacco 308. The smokeable material 308 may in general comprise any suitable smokeable material or blend. The rod of smokeable material 303 also comprises a smoke constituent reducing technology 309 which is capable of reducing the concentration of a smoke constituent in smoke. In the embodiment shown, the smoke constituent reducing technology comprises particles of a smoke constituent reducing additive 309. As shown in Figure 3a, 3b, the tobacco rod 303 comprises a plurality of particles of additive 309 disposed within the tobacco material 308, concentrated in a longitudinal region which extends continuously along the whole length of the rod 303 The particulate additive material 309 may be applied to the smokeable material by any suitable method. The additive 309 is capable of adsorbing a particular target smoke constituent from smoke. The additive is positioned longitudinally along the centre of the smokeable material 308, and in this way, the additive 309 is targeted to a position within the rod of smokeable material 303 corresponding to the central lateral region of the smoking article. Smoking articles having this configuration may therefore be suitable for use when the target smoke constituent has been found to be present in a higher concentration in a central lateral region of the smoking article versus another lateral region.

Other lateral regions of the rod of smokeable material 303, such as the peripheral lateral regions, may comprise a reduced amount of additive 309, such that the additive 309 is concentrated in the central lateral region. Alternatively, the other lateral regions of the rod of smokeable material 303 may comprise no additive 309.

In other embodiments, for example where the smoke constituent may be found to be present at a higher concentration in a non-central lateral position, particles of additive 309 are disposed within the tobacco material 308 extending longitudinally in a corresponding non-central position along the tobacco rod 303. For example, the rod of smokeable material may comprise additive in a peripheral lateral region of the rod of smokeable material 303.

In other embodiments, particles of additive 309 may additionally or

alternatively be located within the smoking article 301 by being incorporated into the wrapping material 304. For example, the additive 309 may be adhered to the inner surface of the wrapping material 304, or adhered to a second inner wrapping material positioned within the outer wrapper 304. The second wrapper material may be a web material, such as a cellulosic paper web, or reconstituted tobacco sheet material. The additive 309 may be adhered to the wrapper 304, or an inner wrapper, as described in WO 2007/104908 and may be present on both faces of the inner wrapper. Any suitable method may be used to apply the additive to the wrapper 304. In other embodiments, the additive 309 may in addition, or alternatively, be incorporated within the structure of the wrapper 304 or an inner wrapper, as described in WO 2010/043475. The wrapper(s) may comprise a paper wrapper material, or an alternative material, such as a reconstituted tobacco material. In addition, the wrapper(s) may comprise particulate sorbent material as described in WO 2010/043475 and wo 99/38396.

The second sheet may be coextensive with the first wrapper 304, or may only be provided at one or more discrete portions. The wrapping material 304 may comprise, in addition or as an alternative to particles of additive, a different type of smoke constituent reducing technology, such as a diluent. The diluent may, for example be carried by sorbent material within the wrapper, as described in

In other embodiments, for example where the smoke constituent has been found to be present at a higher concentration in more than one lateral position, particles of additive 309 are disposed within the tobacco material 308

extending longitudinally along more than one lateral region of the tobacco rod 303. For example, the rod of smokeable material may comprise two, three, or four longitudinally extending lateral regions of particulate material. In some embodiments, the additive 309 may comprise, instead or in addition to particulate material, portions of the carbon fibre thread material described above in respect of the embodiment shown in Figure 2a, 2b.

The additive 309 may be inserted into the smokeable material 308 during formation of the rod of smokeable material 303.

When the smoking article 301 of Figure 3 is in use, combustion of the rod of smokeable material 303 generates smoke which is drawn through the smoking article 301. The smoke constituent may be produced at a higher concentration in the central lateral region and due to the targeted positioning of the smoke constituent reducing additive 309 the concentration of the smoke constituent may be reduced.

In some embodiments, the particulate material 309 present in the rod of smokeable material are particles of a porous carbon material and the smoke constituent reducing additive is carried within the pores of the porous material. In some embodiments, heat from the combustion of the smokeable material causes the release of the additive from the porous particulate material. The porous material may also function as a smoke constituent reducing additive. Alternatively, or in addition, the particulate material 309 may be impregnated with one or metals such as silver or copper, which may be capable of acting as a catalyst to remove or reduce smoke constituents.

By means of the arrangement shown in Figures 3a, 3b, a smoke constituent reducing additive 309 may be targeted to specific lateral regions within the rod of smokeable material 303. Specifically, the additive 309 may be incorporated into the rod of smokeable material at one or more lateral regions which substantially coincide with the lateral regions at which a target smoke

constituent has been found to occur at a higher concentration.

The arrangement of one or a plurality of smoke constituent reducing additives in the smoking article may be controlled to reduce the concentration of the smoke constituent present at the one or more first lateral regions at which the constituent has been found to occur at a higher concentration. Optionally one or a plurality of smoke constituent reducing additives may also be included to target one or more second lateral regions in which the smoke constituent has been found to occur at a lower concentration.

In accordance with embodiments of the type shown in Figure 3a, 3b, the arrangement of two or more smoke constituent reducing technologies, which may be the same or different technologies, at two or more lateral positions in the smoking article may be used to facilitate reductions of smoke constituents at lateral positions where smoke constituents may be generated at both higher and lower concentrations. Specifically, the arrangement of the smoking article shown in Figure 3 allows the accurate incorporation of one or more different smoke constituent reducing technologies into specific location(s) in the smoking article. For example, as described above, the one or more additives 309, the content of the smokeable material 308, and the wrapper 304, or any combination of these parts, may comprise one or more smoke constituent reducing technologies. The location of the technologies may be easily and accurately controlled, by adjusting the materials used and the position and quantity of additive 309, to target one or more smoke constituents based on prior measurements of the concentration of the smoke constituents present at different locations when the smoking article is in use. In some embodiments, the smoking article may comprise a combination of different smoke constituent reducing technologies. Different smoke constituent reducing technologies may be used in combination as appropriate. For example, the wrapper 304 may be a wrapper comprising a smoke constituent reducing technology as described above in respect of the embodiment of Figure la, lb. In another example, a smoking article may comprise additive 309 in combination with one or more threads as described above in respect of the embodiment of Figure 2a, 2b. Alternatively, the co-axial arrangement of Figure la, lb may be used in combination with the particulate additive of Figure 3a, 3b, and/or with one or more threads as described above in respect of the embodiment of Figure 2a, 2b.

Without wishing to be bound by any theory, the effects of the smoke constituent reducing technologies when longitudinally positioned at different lateral regions in the smoking article may arise from a change in combustion and/or pyrolysis profile of the smoke components in the aerosols generated during the smoking process. This may be the result of the physical presence of these technologies in specific lateral locations within the smoking article, which may exert

physicochemical effects on thermal processes within the combustion and/or pyrolysis zones, resulting in reductions of several smoke constituents. For example, the smoke constituent reducing technology may inherently minimise or eliminate the generation of target smoke constituents, and means of targeting the smoke constituent may include catalysis, absorption or other physical means, chemical reaction, and exothermic or endothermic means. In smoking articles in which the smoke reducing technology is positioned distal from the coal, such as in the filter, the smoke constituent reducing technology may inherently minimise or eliminate the generation of target smoke

constituents. Means of targeting the smoke constituent may include catalysis, absorption or other physical means, and by means of chemical reaction. As discussed in the specific Examples, co-axial cigarette constructions where longitudinal smoke constituent reducing technologies are located at different lateral positions demonstrate reductions in the level of specific targeted smoke constituents in comparison to control smoking articles.

The methods and systems of the present disclosure, as described above and shown in the accompanying Figures, provide for improved smoking articles and techniques for making the same. It will be apparent to those skilled in the art that various modifications and variations can be made to the smoking article and method of the disclosed embodiments without departing from the spirit and scope of the disclosed embodiments. Thus, it is intended that the present disclosure includes modifications and variations that are within the scope of the subject disclosure and equivalents. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/ or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.

The following examples are provided to illustrate the present invention and should not be construed as limiting thereof. Examples

Experimental System and Procedure

A suitable experimental system for obtaining samples of gases from the burning portion of a smoking article at various times and at various locations within the smoking article, before, during and after a puff, is described below. Untipped tobacco rods were prepared, 70 mm long and 8 mm in diameter. The cigarette paper had a permeability of 180 cms min ¹ (10 cm²)-¹ (10 cm water and the tobacco was cut at 56 cuts per inch. The cigarettes were selected for weight (0.99 ± 0.02 g) and pressure drop (9.3 ± 0.5 cm water at an air flow of 17.5 cm³ s ¹), and were conditioned at 2i°c and 60% relative humidity.

The cigarettes were smoked in an atmosphere of 21% v/v oxygen/79% v/v argon inside a cubic Perspex chamber of 140 mm side. The gas mixture was passed vertically through the chamber at a flow rate of 250 cms equivalent to a linear velocity of 12.8 mm s ¹ or 0.18 miles per hour past the cigarette. This is equivalent to a Beaufort force o air condition ("calm air"). Under these conditions, the burn rates of the cigarette during the third puff, and in the preceding smoulder period were the same as when the cigarette was smoked in open air (1.29 and a mean 0.069 mm s ¹ respectively). Furthermore, no decrease in the bulk concentration of oxygen in the smoking chamber could be detected as the cigarette smouldered, or when puffs were taken. The puff by puff carbon monoxide deliveries were effectively the same in the smoking chamber as when smoked in open air. The smoke was withdrawn from the cigarette using a quartz probe/thermocouple mounted radially into the cigarette, filtered using a mini-Cambridge filter unit, and analysed using a quadrupole mass spectrometer.

The gas concentrations during the third puff in the smoking regime was determined, together with those during the smoulder period before and after that puff. The cigarette was smoked singly in the smoking chamber using a Cigarette Components Ltd. C.S.M.10 smoking machine, taking a 35 cms puff of 2 seconds duration, once per minute under restricted smoulder conditions. The pressure-time profile of the puff was square.

For a given position of the probe in the cigarette, at least four replicate experiments were performed. The mass spectrometer was systematically calibrated before each replicate experiment, using known gas mixtures. In successive experiments, the probe was inserted into the cigarette for distances of o, 1, 2, 3 and 3.5 mm from the central axis, and at distances of between -10 and +10 from the line of paper burn at the start of the puff (Table 1). Table 1

INITIAL POSITIONS OF PROBE FOR THE INTERNAL CONTOUR DETERMINATIONS*

* Axial positions in the unbumt tobacco rod are given as negative distances from the line of paper burn, the burn line is given the axial position of zero, and positions in the coal and ash are given as positive distances from the burn. line .

** The distance at the s tart of the third puff in the smoking regime.

During the puff , the paper burn line moves down the tobacco rod with a linear speed of 1. 29 mm s^{- 1} . For about 15 s af ter the end of the puf f , the paper burn line is stationary; it them moves with a linear speed of 0.069 mm. s^{_ i} .

Results of smoke constituent concentration determination

Example gas concentration profiles obtained before, during and following a 2- second puff for one position of the probe during the cigarette, are shown in Figure 4. The profiles shown in Figure 4 illustrates the gas concentration as a function of time, from the start of the puff, or axial distance from the burn line, for a given initial position of the probe in the cigarette. The 95% confidence limits of each mean point (mean of four replicates) are also shown. These depend on the quantity of gas and the position in the smoking cycle.

Example contour distributions of temperature, oxygen, carbon monoxide, carbon dioxide, hydrogen and propane inside the combustion coal of the cigarette, at various stages during and following the third puff are given in Figures 5-10.

In Figures 5-10, the x-axis is the distance from the line of paper burn (mm) and the y-axis is the diameter of the cigarette (which was 8mm). The gas concentration contour distributions shown in Figures 5-10

are obtained from a combination of many profiles for different initial probe positions, and show the gas concentration distribution throughout the coal at a given time point in the smoking cycle.

Alternate contours in each plot are marked with the value of the contour, and the serrated contours represent valleys. The sign convention of the axial distances used in these diagrams is defined in the first footnote to Table 1. The

temperature distributions were obtained using a thermocouple positioned at the end of the gas sampling probe.

The concentration of the measured analytes (smoke constituents) can be seen to vary considerably across the width of the smoking article. For example, during puffing, oxygen levels drop from about 20 %v/v to near zero near the axial middle of the coal area, whereas carbon monoxide levels generally are at their highest at this position. Carbon dioxide also tends to be high in the axial middle coal area.

Most of the incoming oxygen during the puff appears to be consumed before it can reach the centre of the coal.

Propane concentration seems to be highest in almost symmetrically off set positions axially relative to the coal (Figures 5-9). Figure 10 illustrates the concentration profiles of the analytes 6 seconds from the start of a 2 second puff, (i.e. 4 seconds into the inter-puff smouldering period). Again, oxygen levels approach zero axially in the middle coal area, with carbon monoxide and carbon dioxide tending to be at highest levels in a central lateral region. Propane concentration appears to be highest in symmetrically off set positions axially relative to the coal.

Smoke constituent reducing technologies

Following the observation that carbon monoxide levels are highest near the axial centre of the coal, it was hypothesised that smoke component reducing technologies directed towards carbon monoxide would be effective when longitudinally positioned in a central lateral region of a cigarette. Co-axial design cigarettes similar to those shown in Figure 1 were produced in which smoke constituent reducing technologies directed towards carbon monoxide were longitudinally positioned in central lateral regions of a cigarette. For the purpose of this work, the term 'Smoke Constituent Reducing Technology' is abbreviated to 'SCRT'.

Two different smoke constituent reducing technologies were investigated utilising a co-axial cigarette construction. The smoke constituent reducing technologies are described in Table 2.

Table 2: Smoke Constituent Reducing Technologies

These technologies were included longitudinally within a co-axial cigarette design, in central lateral positions. The effect on smoke chemistry was assessed by comparison with control co-axial cigarettes manufactured from control materials.

Co-axial cigarettes similar to those described above and shown in Figure ι were prepared. The cigarettes were constructed using either of two different types of cigarette paper as the inner wrapper (in), and either of two different types of smokeable material as the first (inner) smokeable material (114) in the inner rod (no). The inner rod was a super-slim cigarette construction, having a diameter of about 17mm. The outer diameter of the cigarettes was about 24-25mm. The coaxial cigarettes were manufactured utilising two cigarette making machines in series, the super-slim tobacco rod from the first machine being fed into the second to enshroud this with an outer annulus of smokeable material and apply the outer overwrap.

The filters (102) of the cigarettes were non-ventilated. According to Figure 1, the outer annulus of smokeable material corresponds to a second smokeable material (115) in the outer rod (112), which circumscribes the inner rod (110).

The co-axial cigarette design requires both an inner and an outer wrapper (see Figure 1, 111, 104). The outer wrapper used was the same for all of the cigarette samples studied, and consisted of 50 CU permeability paper with a basis weight of 23gsm. This paper is referred to as Cigarette Paper 2.

The inner rod wrapper (111) used was variable in different cigarette samples studied. The first type of wrapper, which was the control wrapper and referred to as Cigarette Paper 1, was a 25 CU permeability paper with a basis weight of 23gsm. This wrapper did not comprise a smoke constituent reducing technology.

The second type of wrapper, referred to as "Iron Oxide Paper", was a 45 CU permeability iron oxide type paper where the iron oxide is used as a filler, manufactured by a commercial cigarette paper manufacturer. The paper had a basis weight of 26gsm, with an iron oxide content equivalent to 16.2% w/w iron.

The first type of smokeable material, referred to as 'Blend 1', comprises a blend of defined tobacco materials in known proportions. This blend did not comprise a smoke constituent reducing technology.

The second type of smokable material, referred to as 'Diluent Blend', comprises a mixture of Blend 1 and a sheet material containing a chalk based band-cast sheet with the addition of substances to act as a smoke diluent ('Diluent Sheet'). The Diluent Sheet was blended at 50% inclusion by weight with 'Blend 1'. The Diluent Blend incorporating the Diluent Sheet is designed to dilute the tobacco smoke (and hence smoke constituents) with a smoke diluent - in this case the Diluent Sheet contained triacetin and glycerol to act as smoke diluents. The composition of the Diluent Sheet is presented in Table 3.

Table 3: Composition of the Diluent Sheet of the Diluent Blend

Co-axial cigarettes were constructed to study the effect of incorporating the smoke constituent reducing technologies longitudinally in central lateral positions within the co-axial construction. The following cigarette designs were manufactured, which facilitated a study of the technologies, individually and in combination, on smoke chemistry when compared to co-axial cigarettes made from control materials (control cigarettes). The co-axial cigarette design experimental matrix is given in Table 4.

Table 4: Co-axial Cigarette Design Experimental Matrix

Lateral Position Lateral Position

Cigarette

Comment Sample

Outer Outer

Inner Blend Inner Wrapper

Blend Wrapper

Cigarette

1 Blend l Blend l Cigarette Paper 1

Paper 2 Control Cigarette

(Control)

Cigarette

Blend l Blend l Iron Oxide Paper

2 Paper 2 SCRT-A

(SCRT-A)

Diluent Cigarette

Blend l Cigarette Paper 1

3 Blend Paper 2 SCRT-B

(SCRT-B)

Diluent Cigarette

Blend l Iron Oxide Paper

4 Blend Paper 2 SCRT-A and SCRT-B

(SCRT-A)

(SCRT-B) By comparing Cigarette 2 to Control l, the effect of SCRT-A (Iron Oxide Paper) may be ascertained. By comparing Cigarette 3 to Control 1, the effect of SCRT-B (Diluent Blend) may be ascertained.

By comparing Cigarette 4 to Control 1, the combined effect of SCRT-A (Iron Oxide Paper) and SCRT-B (Diluent Blend) may be ascertained.

A cellulose acetate filter was used on all cigarettes. The filter was not ventilated. The cigarettes were manufactured to a firmness of about 72% and not exceeding a pressure drop of i6ommWG. The cigarettes were smoked under ISO smoking regime, which is set out in Table 5·

Table 5: Smoking Regime

The amounts of carbon monoxide and NFDPM present in the mainstream smoke produced by the cigarettes were determined. The term 'NFDPM' is a term of art, determined utilising a test methodology as would be understood by a skilled person. It is defined as the weight of mainstream smoke particulate matter trapped on a high efficiency particulate filter, minus the weight of nicotine and water on the filter. It is usually expressed in weight units of milligrams per cigarette.

The carbon monoxide content of the smoke was calculated as the ratio of the amount of carbon monoxide to the amount of NFDPM, and is shown in Table 6. Table 6: Carbon Monoxide : NFDPM Ratio of Non-Tip Ventilated Cigarettes

It can be seen from Table 6 that for Cigarette Sample 2 incorporating SCRT-A (Iron Oxide Paper) compared to Control 1, the level of carbon monoxide is reduced relative to the level of NFDPM.

Likewise, for Cigarette Sample 3 incorporating SCRT-B (Diluent Blend) compared to Control 1, there is a reduction in the level of carbon monoxide relative to the level of NFDPM.

Finally, the reduction in the level of carbon monoxide relative to that of NFDPM is also demonstrated for Cigarette Sample 4, which incorporates SCRT-A and SCRT-B, compared to Control 1. Thus, the targeted incorporation of a smoke constituent reducing technology into a smoking article, based on the prior determination of the location of the greatest concentration of the smoke constituent, results in cigarette

constructions having an increased capacity to reduce target smoke constituents relative to NFDPM.

In conclusion, the concentration of carbon monoxide, as an exemplary smoke constituent, produced in a smoking article as it is in use was determined at various lateral positions and at various time points during puffing and between puffs. Carbon monoxide was found to be produced at the highest concentrations in the central lateral region of the smoking article. Smoking articles were therefore produced comprising one or a combination of two different smoke constituent reducing technologies positioned in substantially central lateral regions of the smoking articles to target carbon monoxide. The effect of the smoke constituent reducing technologies on the concentration of carbon monoxide was investigated. The first smoke constituent reducing technology was a wrapper comprising iron oxide, positioned in an intermediate annular region of the smokeable material, and the second smoke constituent reducing technology was the use of a diluent blend in the tobacco blend in a central lateral region of the smokeable material. The results obtained clearly show that the targeted positioning of smoke constituent reducing technologies within a smoking article reduced the concentration of carbon monoxide produced. This method provides a useful new tool to the smoking article designer.

Claims

1. A method of producing a smoking article which in use generates smoke having a smoke constituent, wherein the smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of the smoke constituent, and wherein the method comprises:

concentration, and one or more second lateral regions at which, when the smoking article is in use, the smoke constituent is present at a second concentration which is lower than the first concentration; and,

2. A method of reducing the concentration of a smoke constituent in the smoke produced by a smoking article, wherein the smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of the smoke constituent, and wherein the method comprises: l) determining one or more first lateral regions at which, when the smoking article is in use, the smoke constituent is present at a first

3. A method according to either of claims 1 or 2, wherein the smoke constituent reducing technology is located in the one or more first lateral regions.

4. A method according to claim 3, wherein a smoke constituent reducing technology is also located in the one or more second lateral regions, and the amount of smoke constituent reducing technology located in the one or more first lateral regions is greater than the amount located in the one or more second lateral regions.

5. A method according to any of claims 1-3, wherein the smoke constituent reducing technology is not located in the one or more second lateral regions.

6. A method according to any of claims 3-5, wherein the relative amounts of smoke constituent reducing technology located in the first and second regions is proportional to the relative first and second concentrations of the smoke constituent.

7. A method according to any of the preceding claims, wherein the smoking article further comprises a rod of smokeable material, and the first and second lateral regions are regions of the rod of smokeable material.

8. A method according to claim 7, wherein the rod of smokeable material is generally cylindrical in shape and the first and second lateral regions are located on a diametrical line across the width of the cylinder.

9. A method according to any of the preceding claims, wherein the smoking article further comprises a filter and the smoke constituent reducing technology is located within the filter to reduce the concentration of the smoke constituent present at the one or more first lateral regions.

10. A method according to any of the preceding claims, wherein the smoking article further comprises a filter and the filter comprises portions of varying density to create pressure drop regions to control airflow through the smoking article.

11. A method according to any of the preceding claims, wherein the smoking article comprises two different smoke constituent reducing technologies.

12. A method according to claim 11, wherein the two different smoke constituent reducing technologies are located in the same one or more first lateral regions.

13. A method according to claim 11 , wherein the two different smoke constituent reducing technologies are located in different lateral regions.

14. A method according to any of the preceding claims, wherein the smoking article further comprises a co-axial rod comprising an inner rod of smokeable material circumscribed by an inner wrapper, the inner rod being circumscribed by an outer rod of smokeable material circumscribed by an outer wrapper.

15. A method according to claim 14, wherein the inner wrapper is

impermeable to the passage of smoke constituents.

16. A method according to either of claims 14 or 15, wherein the inner wrapper comprises the smoke constituent reducing technology.

17. A method according to either of claims 14 or 15, wherein the smokeable material of the inner and / or outer rod comprises the smoke constituent reducing technology.

18. A method according to either of claims 14 or 15, wherein the outer wrapper comprises the smoke constituent reducing technology.

19. A method according to any of claims 14-18, wherein one of the inner or outer rods has a higher density relative to the other rod to create a pressure drop to control airflow through the smoking article.

20. A method according to any of claims 14-19, wherein the inner rod comprises a further inner rod of smokeable material circumscribed by a further inner wrapper.

21. A method according to any of the preceding claims, wherein the smoking article further comprises a thread.

22. A method according to claim 21, wherein the smoking article further comprises a rod of smokeable material and the thread extends continuously within the smokeable material along the whole length of the rod of smokeable material.

23. A method according to any of the preceding claims, wherein the smoking article comprises a rod of smokeable material, and wherein the smoke constituent reducing technology comprises particles disposed within the rod of smokeable material.

24. A method according to claim 23, wherein the particles are disposed within the smokeable material.

25. A method according to claim 24, wherein the particles are concentrated in a longitudinal region extending along the rod of smokeable material.

26. A method according to claim 23, wherein the smokeable material is circumscribed by a wrapper and the particles are adhered to the inner surface of the wrapper.

27. A method according to any of the preceding claims, wherein the smoke constituent reducing technology is in particulate or granular form.

28. A method according to any of the preceding claims, wherein the smoke constituent reducing technology comprises an additive.

29. A method according to claim 28, wherein the additive is a sorbent or a catalyst.

30. A method according to any of claims 1-27, wherein the smoke constituent reducing technology comprises a diluent.

31. A method according to any of claims 1-26, wherein the smoke constituent reducing technology comprises a smokeable material which in use generates a concentration of the smoke constituent which is lower than the concentration that is produced by tobacco.

32. A smoking article which in use generates smoke having a smoke constituent, wherein the smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of the smoke constituent, and wherein in use the smoke constituent is present at a first concentration in one or more first lateral regions, and the smoke constituent is present at a second concentration which is lower than the first concentration in one or more second lateral regions, and wherein the technology is targeted to reduce the concentration of the smoke constituent present at the one or more first lateral regions.

33. A smoking article according to claim 32, wherein the smoke constituent reducing technology is located at the one or more first lateral regions.

34. A smoking article according to either of claims 32 or 33, wherein the amount of smoke constituent reducing technology located in the one or more first lateral regions is greater than the amount located in the one or more second lateral regions.

35. A smoking article according to any of claims 32-34, wherein the smoking article further comprises a rod of smokeable material, and the first and second lateral regions are regions of the rod of smokeable material.

36. A smoking article according to any of claims 32-35, wherein the smoking article further comprises a rod of smokeable material, and wherein the smoke constituent reducing technology comprises particles disposed within the rod of smokeable material.

37. A smoking article according to claim 36, wherein the particles are concentrated in a longitudinal region extending along the rod of smokeable material.

38. A smoking article obtainable by the method as claimed in any of claims 1- 31.

39. A smoking article according to any of claims 32-38, wherein the smoking article further comprises a rod of smokeable material, and wherein the smoke constituent reducing technology comprises particles disposed within the smokeable material.