US20220378088A1

US20220378088A1 - Filter element, mouthpiece and cooling element

Info

Publication number: US20220378088A1
Application number: US17/755,695
Authority: US
Inventors: Michael Gregg; Arief RAHMAN; Rosi Ana QOLBI; Sudirman Widiarto; Wuryanto BAKIN; Sulistyo WIDODO
Original assignee: Essentra Filter Products Development Co Pte Ltd
Current assignee: Essentra Filter Products Development Co Pte Ltd
Priority date: 2019-11-06
Filing date: 2020-11-06
Publication date: 2022-12-01
Also published as: EP4054358A1; CN219108721U; WO2021090012A1; JP2023501329A

Abstract

There is disclosed a mouth piece, filter element or cooling element 100 comprising: a longitudinally extending core of filtering material 102; one or more channels 104 extending longitudinally from an end of the core 102; wherein the or each channel 104 has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis I of the mouth piece, filter element or cooling element 100.

Description

The use of tube filter elements and tube mouth pieces in smoking articles is well known in the art. Typically, a tube filter element includes a cylindrical core of filtering material which includes a channel that extends longitudinally from an end of the cylindrical core. A tube filter element is usually included as part of a multi segment filter and the tube filter element is usually positioned at the mouth end of the smoking article to provide a distinctive end appearance. When incorporated into a smoking article a tube filter may, during use, cause the smoke to leave the filter in a concentrated stream directed at the tongue of the user.
In recent years, non-combustible smoking products have become increasingly popular. Such products include heated tobacco products, also known as tobacco heating products or heat-not-burn products. Heated tobacco products generally include tobacco, a heating element and a power source. The heating element heats the tobacco to generate an aerosol which is delivered to the user via a mouthpiece. The mouthpiece may act to mimic the sensory aspects of a traditional smoking article filter. Additionally, some heat not burn products include a cooling element which cools the aerosol before it reaches the mouthpiece.
According to a first aspect of the present invention there is provided a mouth piece or filter element comprising: a longitudinally extending core of filtering material; and one or more channel(s) extending longitudinally from an end of the core; wherein the or each channel has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the mouth piece or filter element, for example the longitudinal axis that extends along the centre of the channel.
The or each channel is configured such that its transverse cross section at a first point along the length of the longitudinally extending core of filtering material may be rotated with respect to an adjacent point along the length of the longitudinally extending core of filtering material. It will be appreciated that the transverse cross section of the or each channel may rotate by more or less than 360 degrees along the length of the or each channel.
The applicant has found that during use, smoke which passes through the mouth piece or filter element is caused to take a non-linear, for example helical or spiral path, through the or each channel. It has been found that, in use, the mouth piece or filter element of the present invention leads to a different smoking sensation in which the smoke feels more dispersed within the mouth as compared to a standard tube filter element or mouthpiece. Without wishing to be bound by theory, it is thought that the non-linear, for example helical or spiral path taken by the smoke leads to these differences in sensory properties. Furthermore, the applicant has found that when the filter element of the present invention is incorporated into a smoking article containing tobacco smoking material which includes clove (e.g. a Kretec tobacco blend), the tobacco smoke has a spicier flavour as compared to a smoking article including a standard tube filter element or mouth piece. Additionally, the applicant has found that when assembled into a tobacco smoking article such as a cigarette, the filter element of the present invention leads to a reduction in the total amount of nicotine free dry particulate matter in the smoke that passes through the filter as compared to a standard tube filter. The applicant has also found that the filter elements of the present invention lead to an increased nicotine free dry particulate matter retention and a greater nicotine retention compared to standard tube filters.
The or each channel may have a transverse cross section which is a modified circle having one or more protuberant portions extending from the edge of the circle towards the centre of the circle. The channel transverse cross section may be a modified circle having two diametrically opposed protuberant portions extending from the edge of the circle towards the centre of the circle. Alternatively, the or each channel may have a cross shaped or substantially rectangular transverse cross section.
The or each channel may include an inner surface which comprises one or more ridges which extend helically (for example along the inner surface of the or each channel) about a longitudinal axis of the mouth piece or filter element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel. The one or more ridges protrude from the inner surface of the or each channel. The one or more ridges may be formed in the inner surface of the or each channel.
In the case of the or each channel having a transverse cross section which is a modified circle having one or more protuberant portions extending from the edge of the circle towards the centre of the circle, then the or each channel has a substantially cylindrical shape in which the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the mouth piece or filter element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
In the case of the or each channel having a transverse cross section which is a cross shape, the or each channel has a substantially cylindrical shape, in which the inner surface of the or each channel comprises four ridges which extend helically about a longitudinal axis of the mouth piece or filter element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
The mouth piece or filter element may comprise: a longitudinally extending core of filtering material; one or more channel(s) extending longitudinally from an end of the core, the or each channel having an inner surface; wherein the inner surface of the or each channel may comprise one or more ridges which extend helically (for example along the inner surface of the or each channel) about a longitudinal axis of the mouth piece or filter element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel. The one or more ridges protrude from the inner surface of the or each channel. The one or more ridges may be formed in the inner surface of the or each channel.
The applicant has found that in use the presence of one or more ridges extending helically about a longitudinal axis of the mouth piece or filter element leads to a different and improved smoke mouth feel compared to a standard tube mouth piece or filter element which has a constant transverse cross section in the longitudinal direction.
The applicant has found that during use, smoke which passes through the mouth piece or filter element is caused to take a helical or spiral path through the or each channel. It has been found that, in use, the mouth piece or filter of the present invention leads to a different smoking sensation in which the smoke feels more dispersed within the mouth as compared to a standard tube filter element or mouthpiece. Without wishing to be bound by theory, it is thought that the helical path taken by the smoke leads to these differences in sensory properties. Furthermore, the applicant has found that when the filter element of the present invention is incorporated into a smoking article containing tobacco smoking material which includes clove (e.g. a Kretec tobacco blend), the tobacco smoke has a spicier flavour as compared to a smoking article including a standard tube filter element or mouth piece.
The applicant has also found that the inclusion of one or more ridges which extend helically about the longitudinal axis of the or each channel may lead to improved filtration as compared to a filter element which includes a channel having a uniform transverse cross section in the longitudinal direction. The one or more ridges may increase the surface area of the inner surface of the or each channel, which leads to an increased surface area for adsorption. The applicant has found that when assembled into a smoking article such as a cigarette, the filter element of the present invention leads to a reduction in the total amount of nicotine free dry particulate in the smoke that passes through the filter as compared to a standard tube filter.
It will be appreciated that the longitudinally extending core of filtering material has an outer surface and an inner surface. The inner surface of the longitudinally extending core of filtering material may define the or each channel. The distance between the outer surface and the inner surface of the core is known as the wall thickness.
Preferably, the longitudinally extending core of filtering material is substantially cylindrical. The longitudinally extending core of filtering material may have a circumference from 14 mm to 25 mm. The filtering material may be a material conventionally employed for tobacco smoke filter manufacture, for example a filamentary material, fibrous material, web material or extruded material. The filtering material may be natural or synthetic filamentary tow, for example cotton or polymers such as polyethylene, polypropylene or cellulose acetate tow.
The filtering material may be a thermoplastic or otherwise spinnable polymer, for example polypropylene, polyethylene terephthalate or polyactide. It may be, for example, natural or synthetic staple fibres, cotton wool, web material such as paper (usually creped) and synthetic non-wovens, and extruded material (e.g. starch, synthetic foams). Preferably, the filtering material is a material which can be hardened using a plasticiser. Preferably the filtering material comprises cellulose acetate filamentary tow.
The total denier of the filtering material may be from around 20,000 to 100,000 g per 9000 m, for example 20,000 to 80,000 g per 9000 m, for example 20,000 to 50,000 g per 9000 m.
In the case of the filtering material being formed from a single bale of tow, the total denier of the filtering material may be from around 20,000 to 50,000 g per 9000 m for example from 30,000 g to 40,000 g per 9000 m, for example from 30,000 g to 38,000 g per 9000 m, for example 30,000 g, 32,000 g, 33,000 g, 37,000 g or 40,000 g per 9000 m.
In the case of the filtering material being formed from two bales of tow, the total denier of the filtering material may be from around 40,000 to 100,000 g per 9000 m for example from 60,000 g to 80,000 g per 9000 m, for example from 60,000 g to 76,000 g per 9000 m, for example 60,000 g, 64,000 g, 66,000 g, 74,000 g or 80,000 g per 9000 m.
The filament denier may be from 5 g to 9 g per 9000 m, for example 5 g, 7.3 g, 8 g or 9.0 g per 9000 m.
Filtering material is typically described by reference to the filament denier, the total denier and the fibre cross section. For example, the filtering material may comprise tow having the following denier: 8.0Y40, 8.0Y32, 7.3Y33, or 9.0Y37. For example, filtering material having a denier of 8.0Y40 means that the filament denier is 8.0 g per 9000 m, the total denier is 40000 g per 9000 m and the filaments have a Y shaped cross section.
The filtering material may comprise a plasticiser. The filtering material may include a plasticiser in an amount of from about 12% to 24% by weight of the filtering material and plasticiser, for example about 14% to 22%, for example about 16% to 20%, for example about 17 to 19%, for example about 18% of the weight of the filtering material and plasticiser.
The amount of plasticiser present in the mouthpiece or filter element is calculated as a percentage of the total weight of the filtering material and plasticiser via the general equation presented below.
$Percentage of plasticiser % = \frac{amount of plasticiser (g)}{amount of plasticiser (g) + amount of filtering material (g)} \times 100$
In the case of fibrous filtering material such as filamentary tow, the plasticiser acts to harden the fibres of the filtering material. Hardening the fibres of the filtering material may improve the shape definition of the filter element, and in particular the definition of the or each channel. For example, the filtering material may comprise plasticised fibres, for example plasticised tow, for example plasticised cellulose acetate tow. The formation of plasticised tow is well known in the art. The plasticiser may be, for example, triacetin, triethyleneglycol diacetate (TEGDA) or polyethylene glycol (PEG). The plasticiser may be applied to the filtering material by spraying onto the surface of the filtering material using methods known in the art.
The filtering material may optionally include a binder material. The filtering material may optionally include a water soluble binder material. Examples of water soluble materials include water soluble polymer materials such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, starches, polyethylene glycols and polypropylene glycols; blends of water soluble binders with plasticisers such as triacetin, triethyleneglycol diacetate (TEGDA), or polyethylene glycol (PEG); and hot melt water soluble binders in particulate form. The inclusion of a water soluble binder material may further enhance the ability of the filter to be readily and swiftly degraded e.g. under environmental conditions.
The filtering material may include an additive. The additive may be a particulate additive. The particulate additive may be any particulate additive suitable for use in a smoke filter—e.g. activated carbon, zeolite, ion exchange resin (e.g. a weakly basic anion exchange resin), sepiolite, silica gel, alumina, molecular sieves, carbonaceous polymer resins and diatomaceous earths. The particulate additive may be a mixture of two, or more, materials. The additive may be a pigment, for example a pearlescent pigment or a thermo-chromatic pigment.
The additive may include a smoke modifying agent (for example a flavourant). The flavouring agent may, for example, be menthol, spearmint, peppermint, nutmeg, cinnamon, clove, lemon, chocolate, peach, strawberry, vanilla etc. The smoke modifying agent (e.g. flavourant) may be applied to the filtering material in liquid form. The smoke modifying agent (e.g. flavourant) may be liquefied prior to application to the filtering material, for example by heating above the melting point, for example by mixing with a liquid carrier. The smoke modifying agent (e.g. flavourant) may be mixed with and applied with a plasticiser, for example by spraying the mixture of smoke modifying agent (e.g. flavourant) and plasticiser onto the filtering material. A preferred smoke modifying agent (e.g. flavourant) is menthol or clove. For example, the additive may be sepiolite granules to which menthol flavourant has been applied.
The mouth piece or filter element of the present invention may have a wall thickness which is not constant because of the presence of the one or more ridges on the inner surface of the or each channel. The wall thickness at the narrowest point may be from 0.6 mm to 2.3 mm, for example 1.8 to 2.3 mm.
The or each channel may be defined by a continuous extruded element, for example formed from a plastic material.
The or each channel may be surrounded by the filtering material.
Preferably, the or each channel is defined by the filtering material, for example such that the or each channel is surrounded by the filtering material. In this configuration, the longitudinally extending core of filtering material includes an outer surface and one or more inner surface, in which the or each inner surface defines the or each channel and the or each inner surface may comprise one or more ridges which extend helically (for example along the inner surface of the or each channel) about a longitudinal axis of the mouth piece or filter element (for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel), the one or more ridges being defined by the filtering material. The one or more ridges may protrude from the inner surface of the or each channel. The or each channel may be substantially cylindrical, although other shaped channels may be possible, for example a channel that is substantially semi-cylindrical. It will be appreciated that while the or each channel may be substantially cylindrical, the transverse cross section will not be circular, for example the transverse cross section may be cross shaped, rectangular or a modified circle which includes one or more protuberant portions extending from the edge of the circle towards the centre of the circle. The non-circular transverse cross section and the varying transverse cross section along the length of the or each channel provides a distinctive appearance which may be useful in combatting counterfeiting.
The or each channel may extend for part of the length of the core of filtering material. The or each channel may alternatively extend along the entire length of the core. Preferably the or each channel extends from the mouth end of the core of filtering material, such that the mouth end of the filter element or the mouth piece has an unusual visual appearance which may be useful in combatting counterfeiting while also providing an interesting visual appearance for the user.
The or each channel may have a diameter at its widest point of from 1.5 mm to, 6 mm for example 1.5 mm to 5 mm
In the case of the mouth piece or filter element having one channel, the channel may have a diameter at its widest point of from 2 mm to 6 mm, for example 3 mm to 5 mm, for example 3.4 mm to 4.8 mm, for example from 3.5 mm to 4.7 mm, for example 3.7 mm or 4.5 mm.
In the case of the mouth piece or filter element having two or more channels, the diameter of each channel at their widest point may be from 1.5 to 3 mm, for example 1.8 mm to 3.0 mm, for example 1.9 mm to 3.0 mm, for example 2 mm.
The one or more ridges may extend along part of the length of the inner surface of the or each channel. Preferably, the ridges extend along the full length of the inner surface of the or each channel. The ridges may have a width of 1.0 mm to 2 mm, for example 1.2 to 1.7 mm, for example 1.5 mm. The ridges may have a height of from 0.2 to 1.5 mm.
The inner surface of the or each channel may comprise one, two, three or four ridges extending helically about a longitudinal axis of the mouth piece or filter element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel. Preferably, the inner surface of the or each channel comprises two ridges extending helically about a longitudinal axis of the mouth piece or filter element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
The mouthpiece or filter element may comprise more than one channel, for example two, three or four channels extending longitudinally from an end of the core.
The outer circumference of the mouthpiece or filter element may be between 14 and 25 mm.
The length of the mouthpiece or filter element may be between 4.0 mm and 50 mm, for example between 5 mm and 32 mm.
The mouth piece or filter element may be for use as part of a tobacco smoke filter or filter for a non-tobacco smokable material, for example marijuana. The mouthpiece or filter element of the present invention may be incorporated into a multi-segment filter as a single segment. This would allow for an increase in the number of features that could be incorporated into the filter. For example, a mouthpiece or filter element of according to any statement set out above may be joined with a further filter element containing an additive e.g. granular additive e.g. activated carbon granules. The mouthpiece or filter element of the present invention may be joined with a filter element containing a capsule e.g. a frangible capsule, e.g. a capsule containing a flavourant. The mouthpiece or filter element of the present invention may be joined with a filter element containing a flavourant e.g. (menthol) or multiple flavourants.
The mouth piece or filter element of the present invention may be incorporated into a smoking article, such as a cigarette, cigarillo, cigar and the like. The mouthpiece or filter element of the present invention may be incorporated into a tobacco heating product or an e-cigarette. The mouth piece or filter element may also be used alone or as part of a filter which is assembled by a user to form a smoking article, for example a roll-your-own smoking article.
In a further aspect of the present invention, there is provided a filter, for example a tobacco smoke filter, comprising a filter element according to any statement set out above. The filter, for example a tobacco smoke filter, may further comprise one or more further filter element(s). Such a filter which comprises more than one filter element may be referred to as a multi segment filter.
The one or more further filter elements may comprise a longitudinally extending core of filtering material as defined above. The one or more further filter elements may comprise an additive.
The one or more further filtering element may include fully enclosed (e.g. embedded) pocket(s) of additive embedded therein. The additive may be a particulate additive such as activated carbon (see above), which is for example enclosed within the filtering material as a discrete pocket or pod of particles of particulate additive which is substantially separate from, and fully enclosed within, the filtering material. In another example, the fully enclosed (e.g. embedded) pocket(s) of additive may be a frangible capsule or capsules, or one or a plurality of frangible microcapsules. The capsule(s) or microcapsule(s) may contain a variety of media—e.g. a smoke modifying agent such as a flavourant (such as those flavourants disclosed above) and/or a liquid, solid or other material e.g. to aid smoke filtration. The use of capsules or microcapsules is well known in the art.
The one or more further filter elements may include a flavourant provided in and/or on a thread. “Flavour Thread” filter elements are well known in the art. Such filter elements incorporate a thread or tape element, typically longitudinally aligned therein, the element carrying a smoke modifying agent such as a flavourant.
The filter may comprise an outer wrapper, for example plugwrap, which surrounds the filter element or one or more filter elements. The wrapper may be paper, for example an air permeable paper. The wrapper may have a weight from 20 to 50 grams per square metre, for example from 27 to 35 grams per square metre. Particulate additives such as those discussed above may be applied to the wrapper or plugwrap surrounding the filter material, for example as described in GB 2261152. The further filter element may be wrapped by an outer wrapper, for example a plugwrap, which surrounds the further filter element. The filter element as defined according to any statement set out above and the further filter element may together be wrapped by an outer wrapper, such as a plug wrap. The outer wrapper may function to join the filter elements and secure them in place.
The filter may comprise a first filter element and a second filter element, the first filter element comprising a longitudinally extending core of filtering material; one or more channels extending longitudinally from an end of the core; wherein the or each channel has a cross shaped transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the mouth piece or filter element. The second filter element may comprise a longitudinally extending core of filtering material (for example as defined above), and a capsule (for example a frangible capsule) that is fully enclosed within the core of filtering material. The capsule may comprise a smoke modifying agent such as a flavourant, for example menthol, spearmint, peppermint, nutmeg, cinnamon, clove, lemon, chocolate, peach, strawberry, vanilla or the like. The filter may comprise a plugwrap which surrounds the first and second filter elements. A further plugwrap may individually surround the second filter element.
In a further aspect of the present invention there is provided a smoking article comprising a filter, filter element or mouthpiece as described above. The smoking article may include a filter as set out above that is joined to a wrapped rod of smoking material such as tobacco smoking material. Generally, in the case of a smoking article comprising marijuana smoking material, the smoking article includes a mouth piece according to any statement set out above. The smoking article may further comprise a tipping wrapper, for example a tipping paper. The tipping wrapper joins the wrapped rod of smoking material to the filter or mouthpiece by engaging around the adjacent ends of the filter or mouthpiece and the wrapped rod of smoking material. The tipping wrapper may be configured to leave some of the outer surface of the filter/mouthpiece or filter wrapper exposed. The filter may be joined to the wrapped rod of smoking material by a full tipping wrapper which engages around the full filter or mouthpiece length and the adjacent end of the rod of smoking material.
The mouthpiece, filter element, filter or smoking article according to the invention may be unventilated, or may be ventilated by methods well known in the art, e.g. by use of a pre-perforated or air-permeable filter wrapper (plugwrap) or tipping wrapper (tipping paper), and/or laser perforation of the filter wrapper and/or tipping wrapper. The mouthpiece, filter, filter element or smoking article according to the invention may be ventilated by laser perforation of the longitudinally extending core of filtering material (as well as wrapper(s) (plugwrap) and tipping wrapper (tipping paper) if present). A ventilating full tipping wrapper (tipping paper) may likewise be inherently air-permeable or may be provided with ventilation holes, and for ventilated products where both filter wrapper (plugwrap) and tipping wrapper (tipping paper) are present, ventilation through the tipping wrapper (tipping paper) will usually be in register with that through the filter wrapper (plug wrap). Ventilation holes through a filter wrapper (plugwrap), or through a tipping wrapper (tipping paper), or through both simultaneously, may be made by laser perforation during mouthpiece, filter or filter element production.
In a further aspect of the present invention there is provided a multiple rod comprising a plurality of mouthpieces or filter elements according to the invention arranged end-to-end in a mirror image relationship.
In a further aspect of the present invention, there is provided a cooling element comprising a longitudinally extending core of filtering material; one or more channel(s) extending longitudinally from an end of the core; wherein the or each channel has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the cooling element, for example the longitudinal axis that extends along the centre of the channel.
The or each channel is configured such that its transverse cross section at a first point along the length of the longitudinally extending core of filtering material may be rotated with respect to an adjacent point along the length of the longitudinally extending core of filtering material. It will be appreciated that the transverse cross section of the or each channel may rotate by more or less than 360 degrees along the length of the or each channel.
The applicant has found that in use an aerosol which is generated from heating tobacco is cooled as the aerosol passes through the or each channel. The applicant has found that the or each channel causes the aerosol to take a non-linear, for example helical or spiral, path through the or each channel, which has the effect of cooling the aerosol.
The or each channel may have a transverse cross section which is a modified circle having one or more protuberant portions extending from the edge of the circle towards the centre of the circle. The or each channel transverse cross section may be a modified circle having two diametrically opposed protuberant portions extending from the edge of the circle towards the centre of the circle. Alternatively, the or each channel may have a cross shaped or substantially rectangular transverse cross section.
The or each channel may include an inner surface which comprises one or more ridges which extend helically (for example along the inner surface of the or each channel) about a longitudinal axis of the cooling element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel. The one or more ridges protrude from the inner surface of the or each channel. The one or more ridges may be formed in the inner surface of the or each channel.
In the case of the or each channel having a transverse cross section which is a modified circle having one or more protuberant portions extending from the edge of the circle towards the centre of the circle, then the or each channel has a substantially cylindrical shape in which the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the cooling element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
In the case of the or each channel having a transverse cross section which is a cross shape, the or each channel has a substantially cylindrical shape, in which the inner surface of the or each channel comprises four ridges which extend helically about a longitudinal axis of the cooling element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
The cooling element may comprise: a longitudinally extending core of filtering material; one or more channel(s) extending longitudinally from an end of the core, the or each channel having an inner surface; wherein the inner surface of the or each channel may comprise one or more ridges which extend helically (for example along the inner surface of the or each channel) about a longitudinal axis of the cooling element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel. The one or more ridges protrude from the inner surface of the or each channel. The one or more ridges may be formed in the inner surface of the or each channel.
The applicant has found that during use, heated aerosol which passes through the cooling element is caused to take a helical or spiral path through the or each channel. Without wishing to be bound by theory, it is thought that the helical path taken by the heated aerosol cools the aerosol.
It will be appreciated that the longitudinally extending core of filtering material has an outer surface and an inner surface. The inner surface of the longitudinally extending core of filtering material may define the or each channel. The distance between the outer surface and the inner surface of the core is known as the wall thickness.
Preferably, the longitudinally extending core of filtering material is substantially cylindrical. The longitudinally extending core of filtering material may have a circumference from 14 mm to 25 mm. The filtering material may be a material conventionally employed for tobacco smoke filter manufacture, for example a filamentary material, fibrous material, web material or extruded material. The filtering material may be natural or synthetic filamentary tow, for example cotton or polymers such as polyethylene, polypropylene or cellulose acetate tow.
The filtering material may be a thermoplastic or otherwise spinnable polymer, for example polypropylene, polyethylene terephthalate or polyactide. It may be, for example, natural or synthetic staple fibres, cotton wool, web material such as paper (usually creped) and synthetic non-wovens, and extruded material (e.g. starch, synthetic foams). Preferably, the filtering material is a material which can be hardened using a plasticiser. Preferably the filtering material comprises cellulose acetate filamentary tow.
The total denier of the filtering material may be from around 20,000 to 100,000 g per 9000 m, for example 20,000 to 80,000 g per 9000 m, for example 20,000 to 50,000 g per 9000 m.
In the case of the filtering material being formed from a single bale of tow, the total denier of the filtering material may be from around 20,000 to 50,000 g per 9000 m for example from 30,000 g to 40,000 g per 9000 m, for example from 30,000 g to 38,000 g per 9000 m, for example 30,000 g, 32,000 g, 33,000 g, 37,000 g or 40,000 g per 9000 m.
In the case of the filtering material being formed from two bales of tow, the total denier of the filtering material may be from around 40,000 to 100,000 g per 9000 m for example from 60000 g to 80000 g per 9000 m, for example from 60000 g to 76000 g per 9000 m, for example 60,000 g, 64000 g, 66000 g, 74000 g or 80000 g per 9000 m.
The filament denier may be from 5 g to 9 g per 9000 m, for example 5 g, 7.3 g, 8 g or 9.0 g per 9000 m.
Filtering material is typically described by reference to the filament denier, the total denier and the fibre cross section. For example, the filtering material may comprise tow having the following denier: 8.0Y40, 8.0Y32, 7.3Y33, or 9.0Y37. For example, filtering material having a denier of 8.0Y40 means that the filament denier is 8.0 g per 9000 m, the total denier is 40000 g per 9000 m and the filaments have a Y shaped cross section.
The filtering material may comprise a plasticiser. The filtering material may include a plasticiser in an amount of from about 12% to 24% by weight of the filtering material and plasticiser, for example about 14% to 22%, for example about 16% to 20%, for example about 17 to 19%, for example about 18% of the weight of the filtering material and plasticiser.
The amount of plasticiser present in the cooling element is calculated as a percentage of the total weight of the filtering material and plasticiser via the general equation presented below.
$Percentage of plasticiser % = \frac{amount of plasticiser (g)}{amount of plasticiser (g) + amount of filtering material (g)} \times 100$
In the case of fibrous filtering material such as filamentary tow, the plasticiser acts to harden the fibres of the filtering material. Hardening the fibres of the filtering material may improve the shape definition of the cooling element, and in particular the definition of the or each channel. For example, the filtering material may comprise plasticised fibres, for example plasticised tow, for example plasticised cellulose acetate tow. The formation of plasticised tow is well known in the art. The plasticiser may be, for example, triacetin, triethyleneglycol diacetate (TEGDA) or polyethylene glycol (PEG). The plasticiser may be applied to the filtering material by spraying onto the surface of the filtering material using methods known in the art.
The filtering material may optionally include a binder material. The filtering material may optionally include a water soluble binder material. Examples of water soluble materials include water soluble polymer materials such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, starches, polyethylene glycols and polypropylene glycols; blends of water soluble binders with plasticisers such as triacetin, triethyleneglycol diacetate (TEGDA), or polyethylene glycol (PEG); and hot melt water soluble binders in particulate form. The inclusion of a water soluble binder material may further enhance the ability of the cooling element to be readily and swiftly degraded e.g. under environmental conditions.
The cooling element of the present invention may have a wall thickness which is not constant because of the presence of the one or more ridges on the inner surface of the or each channel. The wall thickness at the narrowest point may be from 0.6 mm to 2.3 mm, for example 1.0 to 2.3 mm.
The or each channel may be defined by a continuous extruded element, for example formed from a plastic material.
The or each channel may be surrounded by the filtering material.
Preferably, the or each channel is defined by the filtering material, for example such that the or each channel is surrounded by the filtering material. In this configuration, the longitudinally extending core of filtering material includes an outer surface and an inner surface, in which the inner surface defines the or each channel and the inner surface may comprise one or more ridges which extend helically (for example along the inner surface of the or each channel) about a longitudinal axis of the cooling element (for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel), the one or more ridges being defined by the filtering material. The one or more ridges may protrude from the inner surface of the or each channel. The or each channel may be substantially cylindrical, although other shaped channels may be possible, for example a channel that is substantially semi-cylindrical. It will be appreciated that while the or each channel may be substantially cylindrical, the transverse cross section will not be circular, for example the transverse cross section may be cross shaped, rectangular or a modified circle which includes one or more protuberant portions extending from the edge of the circle towards the centre of the circle.
The or each channel may extend for part of the length of the core of filtering material. The or each channel may alternatively extend along the entire length of the core. Preferably the or each channel extends from the mouth end of the core of filtering material.
The or each channel may have a diameter at its widest point of from 1.5 mm to, 6 mm for example 1.5 mm to 5 mm.
In the case of the cooling element having one channel, the channel may have a diameter at its widest point of from 2 mm to 6 mm, for example 3 mm to 5 mm, for example 3.4 mm to 4.8 mm, for example from 3.5 mm to 4.7 mm, for example 3.7 mm or 4.5 mm.
In the case of the cooling element having two or more channels, the diameter of each channel at their widest point may be from 1.5 to 3 mm, for example 1.8 mm to 3.0 mm, for example 1.9 mm to 3.0 mm, for example 2 mm.
The one or more ridges may extend along part of the length of the inner surface of the or each channel. Preferably, the ridges extend along the full length of the inner surface of the or each channel. The ridges may have a width of 1.0 mm to 2 mm, for example 1.2 to 1.7 mm, for example 1.5 mm. The ridges may have a height of from 0.2 to 1.5 mm.
The inner surface of the or each channel may comprise one, two, three or four ridges extending helically about a longitudinal axis of the cooling element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel. Preferably, the inner surface of the or each channel comprises two ridges extending helically about a longitudinal axis of the cooling element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
The cooling element may comprise more than one channel, for example two, three or four channels extending longitudinally from an end of the core.
The length of the cooling element may be from 5 to 50 mm, for example from 10 to 30 mm, for example 8 to 24 mm, for example 15 to 20 mm, for example 18 mm.
The circumference of the cooling element may be from 12 to 30 mm, for example 15 to 28 mm, for example 17 to 25 mm, for example 18 to 25 mm, for example 20 to 24 mm, for example 22 to 24 mm, for example 23 mm, for example 22 mm. The length of the cooling element may be between 4.0 mm and 50 mm, for example between 5 mm and 32 mm.
The cooling element of the invention may be for use as part of a heated aerosol generating system, for example which may form part of a heated tobacco product.
In a further aspect of the present invention, there is provided a heated aerosol generating system comprising the cooling element as described by any statement above.
The heated aerosol generating system may include a rod of tobacco material, a heating element, a power source, one or more cooling elements according to any statement set out above and a mouthpiece. The one or more cooling elements may be positioned downstream from the heating element and tobacco rod. In use, the tobacco rod is heated to thereby generate a heated aerosol. The heated aerosol then passes through the one or more cooling elements which act to cool the aerosol before it passes through the mouthpiece and into the user's mouth.
In a further aspect of the present invention there is provided a multiple rod comprising a plurality of cooling elements according to the invention arranged end-to-end in a mirror image relationship.
In a further aspect of the present invention there is provided a method of making a mouthpiece, filter element or cooling element comprising: drawing filtering material through a shaping element to form a longitudinally extending core of filtering material, wherein the shaping element comprises a rotating rod having a non-circular transverse cross section, the or each rotating rod forming one or more longitudinally extending channel within the core of filtering material, wherein the or each channel has a transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the mouthpiece, filter element or cooling element.
The or each rod may be substantially cylindrical and include one or more grooves, the one or more grooves forming one or more ridges on the inner surface of the or each channel, the one or more ridges extending helically about a longitudinal axis of the mouthpiece, filter element or cooling element, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
The or each rod may have a cross shaped transverse cross section or the or each rod may have a rectangular transverse cross section.
The shaping element may comprise a chamber into which the or each rotating rod protrudes. The chamber may be cylindrical. As the filtering material passes into the chamber, the walls of the chamber shape the filtering material into a longitudinally extending core of filtering material, for example into a cylindrical rod. As the filtering material passes through the chamber, the filtering material passes around the or each protruding rotating rod to thereby form one or more channel within the filtering material. The rotation of the or each rod causes the transverse cross section of the or each channel to vary in the longitudinal direction by rotating about a longitudinal axis of the longitudinally extending core.
In the case of a rod which includes one or more grooves, the one or more grooves lead to the formation of one or more ridges on the inner surface of the channel. As the rod rotates and as the filtering material passes around the rod and into the one or more grooves in the rod, one or more ridges are formed on the inner surface of the channel that extend helically about the longitudinal axis of the longitudinally extending core of filtering material.
In the case of a rod which has a cross shaped transverse cross section, the channel that is formed has a cross shaped transverse cross section. The rotation of the rod defines a channel that is substantially cylindrical, in which four ridges are formed on the inner surface of the channel that extend helically about a longitudinal axis of the core of filtering material, for example about a longitudinal axis of the channel, for example about the central longitudinal axis of the channel.
It will be appreciated that the diameter of the or each channel at its widest point will be determined by the diameter of the or each rod at the widest point. The size and shape of any grooves in the one or more rod may determine the size and shape of ridges formed on the inner surface of the or each channel. Additionally, the number of grooves present in the or each rod may determine the number of ridges formed on the inner surface of the channel. The helical pitch of the ridges may be determined by the rotational speed at which the rod rotates together with the speed at which the filtering material is drawn through the shaping element.
The filtering material may comprise a plasticiser. The filtering material may include a plasticiser in an amount of from about 12% to 24% by weight of the filtering material and plasticiser, for example about 14% to 22%, for example about 16% to 20%, for example about 17 to 19%, for example about 18% of the weight of the filtering material and plasticiser. The plasticiser may be, for example, triacetin, triethyleneglycol diacetate (TEGDA) or polyethylene glycol (PEG). The plasticiser may be applied to the filtering material before it enters the shaping element, for example the plasticiser may be sprayed onto the filtering material before it enters the shaping element.
The filtering material may be a thermoplastic or otherwise spinnable polymer, for example polypropylene, polyethylene terephthalate or polyactide. It may be, for example, natural or synthetic staple fibres, cotton wool, web material such as paper (usually creped) and synthetic non-wovens, and extruded material (e.g. starch, synthetic foams). Preferably, the filtering material is a material which can be hardened using a plasticiser. Preferably the filtering material comprises cellulose acetate filamentary tow.
The total denier of the filtering material may be from around 20,000 to 100,000 g per 9000 m, for example 20,000 to 80,000 g per 9000 m, for example 20,000 to 50,000 g per 9000 m.
In the case of the filtering material being formed from a single bale of tow, the total denier of the filtering material may be from around 20,000 to 50,000 g per 9000 m for example from 30000 g to 40000 g per 9000 m, for example from 30000 g to 38000 g per 9000 m, for example 30,000 g, 32000 g, 33000 g, 37000 g or 40000 g per 9000 m.
In the case of the filtering material being formed from two bales of tow, the total denier of the filtering material may be from around 40,000 to 100,000 g per 9000 m for example from 60,000 g to 80,000 g per 9000 m, for example from 60,000 g to 76,000 g per 9000 m, for example 60,000 g, 64,000 g, 66,000 g, 74,000 g or 80,000 g per 9000 m.
The filament denier may be from 5 g to 9 g per 9000 m, for example 5 g, 7.3 g, 8 g or 9.0 g per 9000 m.
Filtering material is typically described by reference to the filament denier, the total denier and the fibre cross section. For example, the filtering material may comprise tow having the following denier: 8.0Y40, 8.0Y32, 7.3Y33, or 9.0Y37. For example, filtering material having a denier of 8.0Y40 means that the filament denier is 8.0 g per 9000 m, the total denier is 40000 g per 9000 m and the filaments have a Y shaped cross section.
The filtering material may optionally include a binder material. The filtering material may optionally include a water soluble binder material. Examples of water soluble materials include water soluble polymer materials such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, starches, polyethylene glycols and polypropylene glycols; blends of water soluble binders with plasticisers such as triacetin, triethyleneglycol diacetate (TEGDA), or polyethylene glycol (PEG); and hot melt water soluble binders in particulate form. The inclusion of a water soluble binder material may further enhance the ability of the filter to be readily and swiftly degraded e.g. under environmental conditions.
According to methods for making a mouthpiece or filtering element, the filtering material may include an additive. The additive may be a particulate additive. The particulate additive may be any particulate additive suitable for use in a smoke filter—e.g. activated carbon, zeolite, ion exchange resin (e.g. a weakly basic anion exchange resin), sepiolite, silica gel, alumina, molecular sieves, carbonaceous polymer resins and diatomaceous earths. The particulate additive may be a mixture of two, or more, materials. The additive may be a pigment, for example a pearlescent pigment or a thermo-chromatic pigment.
The additive may include a smoke modifying agent (for example a flavourant). The flavouring agent may, for example, be menthol, spearmint, peppermint, nutmeg, cinnamon, clove, lemon, chocolate, peach, strawberry, vanilla etc. The smoke modifying agent (e.g. flavourant) may be applied to the filtering material in liquid form. The smoke modifying agent (e.g. flavourant) may be liquefied prior to application to the filtering material, for example by heating above the melting point, for example by mixing with a liquid carrier. The smoke modifying agent (e.g. flavourant) may be mixed with and applied with a plasticiser, for example by spraying the mixture of smoke modifying agent (e.g. flavourant) and plasticiser onto the filtering material. A preferred smoke modifying agent (e.g. flavourant) is menthol or clove. For example, the additive may be sepiolite granules to which menthol flavourant has been applied.
The method may include the application of heat to the filtering material as it passes through the shaping element. The application of heat cures the plasticised filtering material causing the filtering material to harden and thereby maintain the shape formed by the shaping element. The heat may be applied to the filtering material by applying steam, for example superheated steam. The steam may applied via an inlet in the shaping element such that the filtering material is heated as it passes through the shaping element.
The method may comprise a step of applying cooling air to the filtering material after it has passed through the shaping element. The cooling air may have a temperature from 20 C to 26 C, for example 22 to 25 C, for example 22 C to 24.5 C.

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

FIG. 1 is an end view of a mouthpiece, filter element or cooling element according to the present invention.

FIG. 2 is a perspective view of a mouthpiece, filter element or cooling element according to the present invention.

FIG. 3 is a side view of a mouthpiece, filter element or cooling element according to the present invention.

FIG. 4 is a sectional view of the mouthpiece, filter element or cooling element shown in FIG. 3 .

FIG. 5 is a sectional view of a mouthpiece, filter element or cooling element shown in FIG. 3 .

FIG. 6 is sectional end view of a mouthpiece, filter element or cooling element according to the invention.

FIG. 7 is an end view of a mouthpiece, filter element or cooling element according to the invention.

FIG. 8 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

FIG. 9 is an end view of a mouthpiece, filter element or cooling element according to the invention.

FIG. 10 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

FIG. 11 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

FIG. 12 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

FIG. 13 is a perspective view of a multi-segment filter according to the invention.

FIG. 1 shows an end view of the mouthpiece, filter element or cooling element according to an embodiment of the present invention. The mouthpiece, filter element or cooling element 100 comprises a longitudinally extending core of filtering material 102. The core of filtering material is substantially cylindrical (as illustrated in FIG. 2 ). The core of filtering material comprises cellulose acetate tow comprising triacetin as a plasticiser in an amount of 18% by weight of the filtering material and plasticiser. The cellulose acetate tow has a filament denier of 7.3 g per 1000 m and a total denier of 36000 g per 1000 m (7.3Y36). The mouthpiece, filter element or cooling element 100 also includes a channel 104 which extends from an end of the core 102 longitudinally through the core 102. The channel 104 is defined by the filtering material which forms the core 102. The channel is surrounded by filtering material. As illustrated in FIGS. 1 and 2 , the channel 104 is positioned centrally with respect to the core 102 and is substantially cylindrical. The mouth piece or filter element has a circumference of 23.4 mm.

As shown in FIG. 2 , the mouth piece, filter element or cooling element includes an outer surface 106 which defines the longitudinally extending core 102. As shown in FIG. 2 , the core 102 extends along the longitudinal axis (I). The longitudinally extending core 102 includes an inner surface 108 which defines the channel 104. The channel 104 extends along the longitudinal axis I of the core 102. The distance between the outer surface 106 and the inner surface 108 is known as the wall thickness and is 1.2 mm. As shown in FIG. 1 , the inner surface 108 includes two ridges 110 which extend helically about the longitudinal axis (I) of the mouth piece, filter element or cooling element. The ridges 110 extend along the inner surface 108 of the channel 104, and the ridges 110 protrude from the inner surface 108 of the channel 104. The two ridges 110 are integral with the inner surface 108 and are defined by the filtering material that makes up the core 102.

FIG. 3 shows a side view of the filter element, mouthpiece or cooling element along the plane defined by the y and I axis shown in FIG. 2 .

FIG. 4 shows a sectional view of the mouthpiece, filter element or cooling element along line A-A, as shown in FIG. 2 . The channel transverse cross section shown in FIG. 4 includes a modified circle having two diametrically opposed protuberant parts which extend from the edge of the circle towards the centre of the circle. The diametrically opposed protuberant parts correspond to the ridges 110 which extend helically about the longitudinal axis of the mouth piece, filter element or cooling element. It will be appreciated that the irregular transverse cross section of the mouth piece and filter elements of the present invention may be useful in combatting counterfeiting. As shown in FIG. 4 , the transverse cross section of the channel 104 is rotated with respect to the channel cross section shown at the end of the filter element 100 as shown in FIG. 2 .

The ridges 110 extend helically with respect to the longitudinal axis (I) of the mouth piece, filter element or cooling element, so the position of the ridge with respect to the circumference of the channel varies along the length of the filter element, mouthpiece or cooling element. Such a non-uniform transverse cross section along the length of the filter element or mouth piece provides further anti-counterfeiting properties.

FIG. 5 shows a further sectional view of the mouthpiece, filter element or cooling element along line B-B as shown in FIG. 3 . As is shown in FIG. 5 , the transverse cross section of the channel 104 is rotated with respect to both the transverse cross section shown in FIG. 4 and the end cross section shown in FIG. 2 .

FIG. 6 shows a sectional view of a further filter element or mouth piece 200 according to the present invention. The filter element or mouthpiece 200 shown in FIG. 6 is similar to that shown in FIGS. 4 and 5 , but includes four ridges 210 extending along the inner surface of the channel 204 helically about the longitudinal axis of the mouth piece, filter element or cooling element.

FIG. 7 shows an end view and FIG. 8 shows a sectional view of a further filter element, mouthpiece or cooling element 300 according to the present invention. The filter element, mouthpiece or cooling element 300 shown in FIGS. 7 and 8 is similar to that shown in FIGS. 1 to 6 , but the filter element, mouthpiece or cooling element 300 shown in FIGS. 7 and 8 has a channel 304 having a rectangular transverse cross section. The transverse cross section of the channel varies in the longitudinal direction of the core by rotating about a longitudinal axis of the mouth piece, filter element or cooling element.

FIG. 9 shows an end view and FIG. 10 shows a sectional view of a further filter element, mouth piece or cooling element 400 according to the present invention. The filter element, mouthpiece or cooling element 400 shown in FIG. 10 is similar to that shown in FIGS. 1 to 8 , but the filter element, mouthpiece or cooling element 400 shown in FIGS. 9 and 10 has a channel 404 having a cross shaped transverse cross section. The transverse cross section of the channel varies in the longitudinal direction of the core by rotating about a longitudinal axis of the mouth piece, filter element or cooling element.

FIG. 11 shows a sectional view of a further filter element, mouth piece or cooling element 500 according to the present invention. The filter element, mouth piece or cooling element 500 shown in FIG. 11 is similar to those shown in FIGS. 1 to 5 , but includes two

channels

504 a and 504 b. Each

channel

504 a, 504 b includes ridges 510 a and 510 b which extend helically about a longitudinal axis of the mouth piece, filter element or cooling element.

FIG. 12 shows a sectional view of a further filter element, mouth piece or cooling element 600 according to the present invention. The filter element, mouth piece or cooling element 600 shown in FIG. 12 is similar to those shown in FIGS. 1 to 5 , but includes three

channels

604 a, 604 b and 604 c. Each

channel

604 a, 604 b, 604 c includes

ridges

610 a, 610 b and 610 c which extend helically about a longitudinal axis of the mouth piece, filter element or cooling element.

Any of the mouthpieces or filter elements illustrated in FIGS. 1 to 12 may form part of a multi segment filter which is included in a smoking article such as a cigarette. Some smoking articles, such as those containing marijuana, include a mouthpiece as described herein and do not include further filter elements such as those included in a multi-segment filter.

During use, smoke travels through the mouthpiece or filter element, and the smoke takes a helical path within the channel which means that smoke emerging from the mouthpiece or filter element will continues to follow a helical path, for example in the mouth of the user. The helical path taken by the smoke affects the mouthfeel of the smoke, as described in further detail in the examples that are set out below.

The cooling element may form part of a heated aerosol generating system which may form part of a non-combustible product, such a heated tobacco product. A heated aerosol generating system typically includes a heating element, a power source, a rod of tobacco, one or more cooling elements and a mouthpiece. The cooling element described herein may be incorporated into the heated aerosol generating system between the mouthpiece and the tobacco rod. During use, the heating element heats the rod of tobacco to form an aerosol. The aerosol then passes into the cooling element and is cooled by the cooling element. Due to the configuration of the channel, the aerosol takes a helically path through the cooling element which reduces the temperature of the aerosol.

The filter elements, mouthpieces and cooling elements shown in FIGS. 1 to 12 may be made by the following process.

Continuously advancing plasticised tow is drawn into a shaping element. The shaping element includes a substantially cylindrical chamber in which a rod (mandrel) protrudes.

The shape of the rod determines the cross sectional shape of the channel. For example, the rod used to make the mouthpiece, filter element or cooling element shown in FIGS. 1 to 5 is a cylinder which includes two diametrically opposed grooves which extend along the length of the cylindrical rod. The rod used to make the mouthpiece, filter element or cooling element shown in FIG. 6 is a cylinder having two pairs of diametrically opposed grooves. The rod used to make the mouth piece, filter element or cooling element shown in FIGS. 7 and 8 has a rectangular cross section, and the rod used to form the mouthpiece, filter element or cooling element shown in FIGS. 9 and 10 has a cross shaped cross section.

In the case of a mouthpiece, filter element or cooling element as shown in FIG. 11 , the shaping element includes two protruding mandrels. In the case of a mouthpiece, filter element or cooling element as shown in FIG. 12 , the shaping element includes three protruding mandrels.

The chamber also includes steam inlets for enabling superheated steam to pass into the chamber. The rod is connected to an external motor which causes the rod to rotate.

As the plasticised tow advances into the chamber, the tow is shaped into a longitudinally extending cylindrical core by the internal walls of the chamber. The chamber acts as a die. While the tow is being shaped by the internal walls of the chamber, the tow is forced around the rod, such that a channel is formed within the core, the channel being defined by the filtering material. The channel shape is defined by the rod as explained above. Rotation of the rod, as the filtering material passes through the chamber, forms a longitudinally extending channel in which the channel cross section varies in the longitudinal direction by rotating about the central longitudinal axis of the channel. In the case of a rod which includes grooves, such as used to make the mouthpiece, filter element or cooling element shown in FIGS. 1 to 6 , the grooves in the rod define ridges on the inner surface of the channel. The rotation of the rod and consequently the rotation of the grooves causes ridges to form on the inner surface of the channel, the ridges extend along the inner surface of the channel and follow a helical path about the longitudinal axis of the channel. It is possible to vary the helical pitch of the ridges by controlling the rotational speed of the rod and the speed at which the tow is drawn through the chamber. The depth and width of each ridge may be modified by varying the depth and width of each groove in the rod. If additional ridges are desired, then the rod may include additional grooves. For example, the mouth piece, filter element or cooling element shown in FIG. 6 makes use of a rod having four grooves.

In the case of a cross shaped rod, the rod forms a channel having a cross shaped cross section. As the rod rotates, a substantially cylindrical channel is formed within the core and the triangular gap between adjacent prongs of the cross shaped rod form ridges on the inner surface of the channel.

In the case of a rod having a rectangular cross section, rotation of the rod means that the cross section of the channel will vary in the longitudinal direction by rotation along the longitudinal length of the core.

The diameter of the channel at its widest point may be varied by changing the diameter of the rod at its widest point. Similarly, the diameter of the core of filtering material may be varied by modifying the diameter of the cylindrical chamber. If a channel is desired which does not include ridges extending along its entire length, then the rod can be modified to include grooves which do not extend along the entire length of the rod.

Superheated steam enters the chamber via the inlet and heats the plasticised tow. The action of heat acts to cure the plasticised tow and thereby hardens the filtering material, such that it retains its shape after leaving the shaping element.

The filtering material exits the shaping element in the form of a substantially cylindrical longitudinally extending core, which includes a longitudinally extending channel within the core. In the case of a rod which includes two grooves, the channel includes two ridges which extend helically along the inner surface of channel about the longitudinal axis of the channel.

The tow may be plasticised as part of the above process before the tow enters the shaping element, for example the continually advancing tow may be sprayed with plasticiser at a plasticising station positioned before the shaping element. Alternatively, the plasticiser may be pre-applied to the tow in a separate process.

The substantially cylindrical longitudinally extending core may be further treated with steam and then cooled by a series of air jets and the substantially cylindrical longitudinally extending core is cut to form a series of individual filter elements, mouth pieces or cooling elements.

FIG. 13 shows a multi-segment filter 700 which includes a filter element 400 which is similar to that shown in FIGS. 9 and 10 . The filter element 400 includes a longitudinally extending core of filtering material 402. The core is substantially cylindrical as shown in FIG. 13 . The filter element 400 also includes a channel 404 which extends from an end of the core 402 longitudinally along the entire length of the core 402. The channel 404 is defined by the filtering material which forms the core 402, and the channel is surrounded by filtering material. The channel 404 is positioned centrally with respect to the core 402. The channel 404 has a substantially cross shaped transverse cross section. As is shown in the cutaway view portion of FIG. 13 , the transverse cross section of the channel 404 varies in the longitudinal direction by rotating about a longitudinal axis of the filter element 400.

As is shown in the cutaway portion of FIG. 13 , the channel includes four ridges 410 which extend helically about the longitudinal axis of the filter element 400.

The multi-segment filter 700 also includes a second filter element 710. The second filter element 710 includes a longitudinally extending core of filtering material 720. As is shown in the second cutaway portion of FIG. 13 , the second filter element 710 includes a capsule 740 which is fully enclosed within the core of filtering material 720. The capsule may be a frangible capsule containing a smoke modifying agent such as a flavourant. It will be appreciated that other additives may be included in the core. The second filter element 710 is wrapped with a first plug wrap 750 and the first filter element 400 and second filter element 710 are together wrapped with a second plug wrap 760 which functions to hold the first filter element and the wrapped second filter element together.

The second filter element may be made according to standard methods known in the art. The first filter element and second filter element may be joined and wrapped using standard manufacturing methods known in the art.

EXAMPLES

Example 1

Four filtered cigarettes including a filter element according to the present invention were prepared along with four control filtered cigarettes. The filtered cigarettes according to the present invention were prepared based on a standard commercially available Kretec (clove flavoured) tobacco cigarette. The standard 27 mm mono cellulose acetate filter was removed from the cigarette and replaced with a multi-segment filter according to the present invention. The multi-segment filter of the present invention included a 20 mm section of the removed standard mono cellulose acetate filter joined to a filter element of the present invention which was 7 mm in length.
The control cigarettes included a multi-segment filter including a 20 mm mono cellulose acetate filter joined to a 7 mm standard tube filter.
The filtered cigarettes were smoked by four users. The users reported that compared to the control cigarette, the filtered cigarettes which included filter elements of the present invention produced tobacco smoke which had a spicier taste, and was more evenly dispersed in the mouth. The users reported that the control cigarettes, which included a standard tube filter element, produced smoke which was concentrated on the tongue.

Example 2

Filtered cigarettes were assembled which included a single filter element as shown in FIG. 1 . Further filtered cigarettes were assembled which included a single filter element as shown in FIGS. 7 and 8 .
Filtered cigarettes were assembled which included a single standard tube filter element which included a channel having a continuous transverse cross section.
Each type of filtered cigarette were tested by smoking under standard conditions and the total nicotine free dry particulate matter (NFDPM) yield was measured (according to standards ISOIS017025, IS03308, IS04387).
The applicant found that the cigarettes which included the filter elements of the invention had a lower NFDPM yield than the cigarettes that included a single standard tube filter element.

Example 3

Filtered cigarettes were assembled. The filtered cigarettes included a multi-segment filter including a single 7 mm standard tube filter element joined to a 20 mm mono-acetate filter. The standard tube filter included a channel having a continuous transverse cross section. The multi-segment filter was joined to a tobacco rod. Further filtered cigarettes were assembled and included a multi-segment filter including either filter element A, B or C. Each of filter element A, B or C was 7 mm in length.
Filter element A is a single filter element as shown in FIGS. 1-5 .
Filter element B is a single filter element as shown in FIGS. 7 and 8 .
Filter element C is a single filter element as shown in FIGS. 9 and 10 .
Total particulate matter (TPM) was measured for each of the tested filter elements. Total particulate matter in the mainstream smoke exiting the filter was measured by performing a smoking test under standard conditions using the method according to ISO 4387. Total particulate matter collected by the filter is measured using gravimetric analysis. The filter is also extracted using isopropanol and the extracted mixture analysed using gas chromatography coupled to a flame ionization detector (GC-FID) to determine the amount of nicotine. This analysis was carried out according to standard ISO10315. The extracted mixture was also analysed using gas chromatography coupled to a thermal conductivity detector (GC-TCD) to determine the amount of water. This analysis was carried out according to standard ISO10362.
The amount of Nicotine free dry particulate matter NFDPM (tar) is calculated by the following formula:
NFDPM=TPM−Nicotine−Water (mg/cig)
Tar and nicotine retention were calculated according to the following equations:
$Nicotine Retention (%) = \frac{Nicotine in filter (mg)}{Nicotine in mainstream smoke + Nicotine in filter (mg)} \times 100 %$ $NFDPM Retention (%) = \frac{NFDPM in filter (mg)}{NFDPM in mainstream smoke + NFDPM in filter (mg)} \times 100 %$
The amount of nicotine in the filter following smoking was measured according to the methods set out above. The amount of NFDPM in the filter following smoking was calculated as set out above.
The results of the NFDPM retention and Nicotine retention are summarised in table 1 below.

TABLE 2

	NFDPM	Nicotine
	retention	retention
Filter	%	%

Standard tube filter element	32	34
Filter element A	36.5	32.5
Filter element B	39.5	36
Filter element C	36	34

As shown in table 1 above, the filters of the present invention (including Filter elements A, B and C) exhibited much higher NFDPM retention as compared to the standard tube filter. Additionally with the exception of filer element A, the filter elements of the invention demonstrated similar or higher nicotine retention compared to the standard tube filter.

Example 4

A cooling element according to the invention was prepared. The cooling element had a configuration as illustrated in FIGS. 1-5 and as described above. The cooling element had a length of 18 mm and a circumference of 22.53 mm.
A comparative cooling element having a length of 18 mm was also formed from crimped polylactic acid (PLA) filter material.
The cooling element according to the invention and the comparative cooling element were each assembled into separate tobacco heated product devices and the devices were smoked using a linear smoking machine under conditions according to standard ISO20778.
The amount of hydroquinone, resorcinol and catechol in the vapour exiting the device was measured using high performance liquid chromatography (HPLC) with fluorescence detection (FLD).
The results from these tests are set out in table 2 below.

TABLE 2

		Comparative
	Cooling	cooling
Parameter	element A	element

Puffs	12	12
Hydroquinone/μg	2.53	4.03
Resorcinol/μg	0.77	0.90
Catechol/μg	4.67	11.09

As illustrated in table 2, the cooling element of the invention significantly reduced the quantities of hydroquinone, resorcinol and catechol present in the vapour exiting the device.

Claims

1. A mouth piece or filter element comprising: a longitudinally extending core of filtering material; one or more channels extending longitudinally from an end of the core; wherein the or each channel has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the mouth piece or filter element.

2. The mouthpiece or filter element according to claim 1, wherein the or each channel has a transverse cross section which is a modified circle having one or more protuberant portions extending towards the centre of the circle.

3. The mouthpiece or filter element according to claim 1, wherein the or each channel has a cross shaped or rectangular transverse cross section.

4. The mouth piece or filter element according to claim 1, wherein the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the mouth piece or filter element.

5. A mouth piece or filter element comprising: a longitudinally extending core of filtering material; and one or more channels extending longitudinally from an end of the core, wherein the or each channel has an inner surface; wherein the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the mouth piece or filter element.

6. The mouth piece or filter element according to claim 1, wherein the or each channel is defined by the filtering material.

7. The mouth piece or filter element according to claim 1, wherein the or each channel extends along the entire length of the core.

8. The mouth piece or filter element according to claim 4, wherein the one or more ridges extend along the entire length of the inner surface of the channel.

9. The mouth piece or filter element according to claim 4, wherein the one or more ridges are integrally formed with the inner surface of the channel.

10. The mouth piece or filter element according to claim 4, wherein the inner surface of the or each channel comprises two ridges.

11. The mouth piece or filter element according to claim 1, comprising two, three or four channels.

12. The mouth piece or filter element according to claim 1, wherein the circumference of the longitudinally extending core of filtering material is from 14 mm to 25 mm.

13. The mouth piece or filter element according to claim 1, wherein the longitudinally extending core of filtering material has a total denier from 20000 to 100000 g per 9000 m.

14. The mouth piece or filter element according to claim 1, wherein the filtering material comprises cellulose acetate.

15. The mouth piece or filter element according to claim 1, wherein the filtering material comprises a plasticiser.

16. A filter, comprising a filter element according to claim 1.

17. A filter according to claim 16, comprising a further filter element joined to the first filter element.

18. A filter according to claim 17, wherein the further filter element comprises an additive.

19. A filter according to claim 16, further comprising second filter element joined to the first filter element, wherein the second filter element comprises a longitudinally extending core of smoke filtering material and a capsule fully enclosed within the core of smoke filtering material, wherein the capsule comprises a smoke modifying agent.

20. A filter according to claim 16, wherein the or each channel has a cross shaped transverse cross section.

21. A multiple rod, comprising a plurality of mouthpieces or filter elements according to claim 1 joined end-to-end in a mirror image relationship.

22. A smoking article, comprising a mouthpiece or filter element according to claim 1, the mouthpiece or filter element being joined to a rod of smokable material.

23. A cooling element, comprising a longitudinally extending core of filtering material; and one or more channels extending longitudinally from an end of the core; wherein the or each channel has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the cooling element.

24. A cooling element comprising: a longitudinally extending core of filtering material; and one or more channels extending longitudinally from an end of the core, the or each channel having an inner surface; wherein the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the cooling element.

25. A heated aerosol generating system comprising the cooling element according to claim 23.

26. A method of making a mouthpiece, filter element or cooling element comprising: drawing filtering material through a shaping element to form a longitudinally extending core of filtering material, wherein the shaping element comprises one or more rotating rods having a non-circular transverse cross section, the or each rotating rod forming one or more channels within the core of filtering material, wherein the or each channel has a transverse cross section that varies in the longitudinal direction by rotating about a longitudinal axis of the mouth piece, filter element or cooling element.

27. The method according to claim 26, wherein the or each rod comprises one or more grooves which form one or more ridges on the inner surface of the or each channel, the one or more ridges extending helically about a longitudinal axis of the mouth piece, filter element or cooling element.

28. A method according to claim 26, wherein the filtering material comprises a plasticiser.

29. A method according to claim 26, wherein heat is applied to the filtering material as it passes through the shaping element.

30. The mouth piece or filter element according to claim 5, wherein the or each channel is defined by the filtering material.

31. The mouth piece or filter element according to claim 5, wherein the or each channel extends along the entire length of the core.

32. The mouth piece or filter element according to claim 5, wherein the one or more ridges extend along the entire length of the inner surface of the channel.

33. The mouth piece or filter element according to claim 5, wherein the one or more ridges are integrally formed with the inner surface of the channel.

34. The mouth piece or filter element according to claim 5, wherein the inner surface of the or each channel comprises two ridges.

35. The mouth piece or filter element according to claim 5, comprising two, three or four channels.

36. The mouth piece or filter element according to claim 5, wherein the circumference of the longitudinally extending core of filtering material is from 14 mm to 25 mm.

37. The mouth piece or filter element according to claim 5, wherein the longitudinally extending core of filtering material has a total denier from 20000 to 100000 g per 9000 m.

38. The mouth piece or filter element according to claim 5, wherein the filtering material comprises cellulose acetate.

39. The mouth piece or filter element according to claim 5, wherein the filtering material comprises a plasticiser.

40. A filter, comprising a filter element according to claim 5.

41. A filter according to claim 40, comprising a further filter element joined to the first filter element.

42. A filter according to claim 41, wherein the further filter element comprises an additive.

43. A filter according to claim 40, comprising a first filter element according to claim 5 and a second filter element joined to the first filter element, wherein the second filter element comprises a longitudinally extending core of smoke filtering material and a capsule fully enclosed within the core of smoke filtering material, wherein the capsule comprises a smoke modifying agent.

44. A filter according to claim 40, wherein the or each channel has a cross shaped transverse cross section.

45. A multiple rod, comprising a plurality of mouthpieces or filter elements according to claim 5 joined end-to-end in a mirror image relationship.

46. A smoking article, comprising a filter according to claim 16, the filter being joined to a rod of smokable material.

47. A smoking article, comprising a mouthpiece or filter element according to claim 5, the mouthpiece or filter element being joined to a rod of smokable material.

48. A smoking article, comprising a filter according to claim 40, the filter being joined to a rod of smokable material.