US20220400743A1

US20220400743A1 - Tobacco smoke filter

Info

Publication number: US20220400743A1
Application number: US17/779,368
Authority: US
Inventors: Patrick Meredith; Michael Gregg; Sudirman Widiarto; Arief RAHMAN; Wuryanto; Robert Whiffen
Original assignee: Essentra Filter Products Development Co Pte Ltd
Current assignee: Essentra Filter Products Development Co Pte Ltd
Priority date: 2019-11-29
Filing date: 2020-11-27
Publication date: 2022-12-22
Also published as: EP3880010A1; CN218457261U; HUE062360T2; CN217161063U; WO2021105427A1; LT3880010T; EP3880010B1; KR20220110232A; PL3880010T3; JP2023503488A

Abstract

A tobacco smoke filter or filter element comprising: a longitudinally extending core which includes first and second longitudinally extending rods of tobacco smoke filtering material, wherein the first rod of tobacco smoke filtering material is distanced longitudinally from the second rod of tobacco smoke filtering material; a wrapper engaged around the first and second longitudinally extending rods such that the wrapper defines a cavity between the first and second rods of tobacco smoke filtering material; and at least one receptacle for an additive located in the cavity, wherein the maximum width or diameter of the receptacle for an additive is less than half the maximum diameter of the cavity and the void space remaining in the cavity is greater than 50% of the volume of the cavity, the receptacle being free to move within the cavity.

Description

The present invention relates to tobacco smoke filters or filter elements for smoking articles such as cigarettes.
Tobacco smoke filters which include a frangible capsule, or a plurality of frangible capsules, embedded in the tobacco smoke filtering material are well-known. These capsules contain an additive (typically a liquid flavouring agent). The smoker applies pressure to the filter to break the capsule therein to release the flavouring agent. The smoker would usually break the capsule immediately prior to smoking, although they may choose to break it at any stage of the smoking process (or not at all). Such capsule filter products are consequently known as ‘flavour-on-demand’, indicating that the smoker chooses when, and if, he requires the release of flavour contained within the capsule.
Tobacco smoke filters which contain a central cavity, surrounded by tobacco smoke filtering material, have been previously described by the applicant e.g. Cavitec® filter. The central cavity is filled with one or more sepiolite granular additives (e.g. a flavourant) with high levels of additive loading. The cavity optimises the effect of the additive providing the user with a consistent flavour level and a cigarette that is always flavoured, including when the pack is first open. However, with these filters the smoker does not have a choice when (if at all) to release the flavour and there is no extra interactive or sensory experience.
According to the present invention there is provided a tobacco smoke filter or filter element comprising: a longitudinally extending core which includes first and second longitudinally extending rods of tobacco smoke filtering material, wherein the first rod of tobacco smoke filtering material is distanced longitudinally from the second rod of tobacco smoke filtering material; a wrapper engaged around the first and second longitudinally extending rods such that the wrapper defines a cavity between the first and second rods of tobacco smoke filtering material; and at least one receptacle for an additive located in the cavity, wherein the maximum width or diameter of the receptacle for an additive is less than half the maximum diameter of the cavity and the void space remaining in the cavity is greater than 50% of the volume of the cavity, the receptacle being free to move within the cavity.
The phrase “being free to move within the cavity” means the receptacle is not fixed or adhered (e.g. with adhesive) within the cavity and has sufficient space to move in all directions (e.g. up, down, forward, back, left, right) in the cavity. When the filter element is moved or shaken the receptacle may move freely in any direction within the cavity. The movement of the receptacle is audible and palpable. It can be sensed (e.g. heard or felt as a vibration) by the user. Herein the term “audible” means within the accepted human hearing range for pitch (Hz) and loudness (dB) i.e. 20 to 20,000 Hz and 0 to 85 dB. Herein the term “palpable” means able to be touched or felt.
The applicants have found that tobacco smoke filter and filter elements of the invention may provide a unique and enhanced sensory experience for the smoker. Inclusion of a freely moving capsule or capsules within the cavity, capable of moving in all directions within the cavity, creates an audible and palpable rattle when the filter is moved, and an audible and palpable ‘pop’ when the capsule is broken. These features provide the smoker with both aural and haptic sensations for an enhanced sensory experience when smoking. The movement of the capsule or capsules in all directions within the cavity generates vibrations, the frequencies of which can vary depending on the number, size and composition of capsules as well as the length and circumference of the cavity and the weight, opacity and composition of the wrapper engaged around the cavity. The vibrational frequencies provide the smoker with a new and different feel compared with a conventional filter. The vibrational frequencies of the freely moving capsules may be in particular use in combating anti-counterfeiting, a major problem in the cigarette industry. The vibrational frequencies and audible rattle created by the free movement of the capsule or capsules within the cavity are distinctive and could help to deter counterfeiting of the brand.
The longitudinally extending core may be substantially cylindrical (including at least the first and second rods of tobacco smoke filtering material and the cavity therebetween). In other words the core is formed from two spaced rods of tobacco smoke filtering material, rather than a single rod of tobacco smoke filtering material. The first rod of tobacco smoke filtering material is distanced longitudinally from the second rod of tobacco smoke filtering material leaving a space therebetween. Preferably the space between the first rod of tobacco smoke filtering material and the second rod of tobacco smoke filtering material is of length 3.5 mm to 32 mm e.g. 3.5 to 26 mm, e.g. 4 to 22 mm, e.g. 5 to 21 mm, e.g. 7 to 14 mm. The first rod of tobacco smoke filtering material and the second rod of tobacco smoke filtering material may be of the same length or of different length.
The tobacco smoke filtering material of the first rod of tobacco smoke filtering material and the tobacco smoke filtering material of the second of rod tobacco smoke filtering material may be composed of the same or different filtering materials. Preferably the filtering materials are cellulose acetate (e.g. in the form of a crimped filamentary tow). However, cotton or plastics such as polyethylene or polypropylene, natural or synthetic staple fibres, cotton wool, a web material such as paper (usually creped), an (e.g. synthetic) non-woven material, and/or an extruded material (e.g. starch, synthetic foams, extruded foams) are also acceptable. The filtering materials may comprise carbon (e.g. activated carbon) to reduce vapour phase and semi-volatile components in mainstream smoke without the need for ventilation. The filtering material may be cellulose acetate to which a plasticiser has been applied (e.g. plasticised filamentary tow). Triacetin is well known in the art and is typically applied to cellulose acetate filters as a plasticiser (e.g. at around 6-8% w/w).
The tobacco smoke filter or filter element comprises one or more receptacles for an additive. Herein the term “receptacle for an additive” refers to the, or each receptacle for an additive where there is more than one receptacle. Preferably the receptacle for an additive is a capsule (e.g. a frangible capsule). Preferably the receptacle for an additive (e.g. capsule e.g. frangible capsule) includes an additive in the form of a flavourant. The flavourant may be any flavourant known or suitable for use in a smoking article such as a cigarette, for example menthol, spearmint, peppermint, fenugreek, clove etc. The receptacle for an additive may be coloured to identify the flavourant enclosed (e.g. a green capsule for menthol). The receptacle for an additive may comprise more than one flavouring agent (and may provide blends of different flavours). When there is one or more receptacles for an additive the receptacles may contain the same flavourant, or different flavourants. In this example, the user is able to vary the amount of flavourant they receive, and when they receive it, by breaking the required number of receptacles e.g. the user may break one receptacle for an additive at the beginning of smoking and one receptacle for an additive during smoking, allowing the user to vary the smoking experience e.g. provide a boost of flavour during smoking.
The receptacle for an additive (e.g. a capsule e.g. a frangible capsule) and/or the tobacco smoke filtering material may contain one or more additives, for example a flavourant and/or a liquid, solid or other material, such as activated carbon, e.g. to aid smoke filtration. The receptacle for an additive and/or tobacco smoke filtering material may further contain stimulants, water, tobacco extracts, smoke altering chemicals and/or agents to promote degradation of the filter. The receptacle for an additive (e.g. capsule e.g. frangible capsule) may be of maximum width 2 to 5 mm, e.g. 2.5 to 4 mm, e.g. 2.5 to 3.9 mm, e.g. 3.0 to 3.8 mm, e.g. 3.2 to 3.7 mm, e.g. 3.35 or 3.5 mm. The maximum width herein refers to the measurement across the receptacle at its broadest point, so for a spherical capsule or substantially cylindrical capsule it refers to the diameter. The receptacle for an additive may include from 5 to 30 mg flavourant, e.g. 7 to 25 mg, e.g. 10 to 25 mg, e.g. 10 to 20 mg.
The receptacle for an additive (e.g. a capsule e.g. a frangible capsule) is freely moveable within the central cavity. This means that the receptacle for an additive is not fixed or adhered (e.g. with adhesive) to the filter wrapper or the first and second rods of tobacco smoke filtering material. The maximum width or diameter (if spherical or substantially spherical) of the receptacle is less than half the maximum diameter of the cavity. The volume of the receptacle (e.g. the space the receptacle occupies) is such that the void space (e.g. the space the receptacle does not occupy) remaining in the cavity is greater than 50% of the volume of the cavity (e.g. 51 to 90%, e.g. 55 to 80% e.g. 60 to 75%). The receptacle for an additive is therefore free to move in all directions (e.g. longitudinally and latitudinally) within the void space in the cavity and in doing so creates an audible and palpable rattle when the filter is moved or shaken. The receptacle for an additive is not visible (to the smoker) at the mouth or buccal end of the filter or filter element, or at the mouth end of a cigarette including a filter of this aspect of the invention.
The applicants have surprisingly found that positioning of a free moving capsule within the cavity supplies a greater yield of flavourant to the user compared to positioning of the capsule embedded (and immovably) within the tobacco smoke filtering material. The menthol yield in the smoke is higher when the crushed capsule is positioned within the cavity (and is free to move within the cavity) thus the smoker experiences increased flavour delivery.
The wrapper is engaged around the longitudinally extending core and engaged around the first and second rods of tobacco smoke filtering material and defines a cavity between the first and second rods of tobacco smoke filtering material. The closest ends (e.g. the facing ends) of the first and second rods of tobacco smoke filtering material, together with the internal surface of the wrapper define the cavity. At least one receptacle for an additive is freely located in the cavity. Preferably the cavity is of length 3.5 mm to 32 mm e.g. 3.5 to 25 mm, e.g. 4 to 22 mm, e.g. 5 to 21 mm, e.g. 7 to 14 mm. The cavity may be of circumference from 14 to 28 mm, e.g. 16 to 26 mm, e.g. 16 to 25 mm, e.g. 16 to 19 mm, e.g. 24 to 25 mm. The cavity may have a maximum diameter from 5 mm to 10 mm, e.g. 5.3 mm to 7.8 mm. It will be appreciated that the circumference and diameter of the cavity will be substantially the same as the circumference and diameter of the filter or filter element. The cavity may vary in position within the longitudinally extending core, for example the cavity may be substantially central within the longitudinally extending core or positioned towards one end of the longitudinally extending core.
Adhesive is applied to the wrapper in register with the plugs of tobacco smoke filtering material but not in register with the space between plugs. In other words, the region of the cavity is free of adhesive and only the first and second rods of tobacco smoke filtering material are adhered to the wrapper. This allows the capsule to move freely in the central cavity. The adhesive may be any conventional filter wrapper adhesive known in the art and may be applied by methods well known in the art.
In a further example, the wrapper may be coloured (e.g. green) and/or transparent providing further visual differentiation from conventional filters. A transparent wrapper provides a window into the cavity allowing the smoker to see the freely moveable receptacle for an additive. The user can establish whether or not the capsule has been broken by looking through the window or identify the flavourant in the receptacle (e.g. a green capsule for menthol). The use of a window may also be used as an anti-counterfeiting measure as this distinct appearance may deter manufacture of counterfeits. The colour of the wrapper (e.g. a green wrapper for menthol) may also be used to identify the flavour provided by the receptacle for an additive.
The wrapper may be a paper, e.g. plugwrap. The wrapper may be coated to minimise absorption of liquids released from the ruptured capsule, as is well-known in the art. The wrapper may be standard or porous depending on ventilation requirements. The wrapper may be air permeable filtering paper (e.g. corrugated air permeable filtering paper) or a wrapper of cellulose acetate (e.g. crimped air permeable cellulose acetate). The weight of the inner wrapper may be from 23 grams per square meter to 100 grams per square meter, e.g. 80 grams per square meter. The wrapper may include a still further flavouring agent located thereon, which may be any flavouring agent known for use in tobacco smoke filters or filter elements (e.g. the flavouring agent may be menthol, spearmint, peppermint, nutmeg, cinnamon, clove, lemon, chocolate, peach, strawberry, vanilla etc.). The wrapper may be opaque, with an opacity of 71% or more (e.g. 71% to 100%, e.g. 71% to 80%, e.g. 80% to 90%, e.g. 90% to 100%). Herein the term “opacity” means a value measured according to ISO 2471:2008 Paper and board—Determination of opacity (paper backing)—Diffuse reflectance method). The weight and opacity of the wrapper may influence the vibrational frequencies generated by the movement of the capsule or capsules in all directions within the cavity. Further the weight and opacity of the wrapper may affect the aural and haptic sensations experienced by the user when the filter or filter element is moved or shaken.
The tobacco smoke filter or filter element may be of length 10 to 45 mm, e.g. 15 to 35 mm e.g. 11 to 25 mm, e.g. 12 to 16 mm, e.g. 20 to 30 mm. The filter or filter element may be of circumference from 14 to 28 mm, e.g. 16 to 26 mm, e.g. 16 to 25 mm, e.g. 16 to 19 mm, e.g. 24 to 25 mm. The filter or filter element may have a maximum diameter from 5 mm to 10 mm, e.g. 5.3 mm to 7.8 mm. The tobacco smoke filter or filter element may be used in smoking articles (e.g. a cigarette, e.g. a tobacco heat product) in a variety of different circumferences (e.g. microslim e.g. superslim, e.g. slim, e.g. standard, e.g. king size).
The present invention provides a smoking article (e.g. cigarette, e.g. tobacco heat product) comprising a tobacco smoke filter or filter element according to the invention. The tobacco smoke filter or filter element of the present invention is suitable for use with all varieties of tobacco blends. In a filter smoking article according to the invention, a filter of the invention (or a filter which includes a filter element of the invention) is joined to a wrapped tobacco rod with one end of the filter towards the tobacco. The filter may be joined to the wrapped tobacco rod by ring tipping [which engages around just the adjacent ends of the (wrapped) filter and rod to leave much of the filter wrap exposed]. The filter may be joined by a full tipping overwrap (which engages around the full filter length and the adjacent end of the tobacco rod).
The invention includes (e.g. double and higher) length filter rods (and/or filter element rods), including a plurality of filter rods (filter element rods), e.g. joined end to end. The tobacco smoke filter or filter element may also be incorporated into a multi-segment filter as a single segment.
The invention provides a method of making a tobacco smoke filter or filter element comprising: a longitudinally extending core which includes first and second longitudinally extending rods of tobacco smoke filtering material, wherein the first rod of tobacco smoke filtering material is distanced longitudinally from the second rod of tobacco smoke filtering material; a wrapper engaged around the first and second longitudinally extending rods such that the wrapper defines a cavity between the first and second rods of tobacco smoke filtering material; and at least one receptacle for an additive located in the cavity, the receptacle being free to move within the cavity. The method comprises the steps of:

- (a) arranging plugs of tobacco smoke filtering material on a filter wrapper (e.g. garniture) longitudinally at intervals so as to leave spaces between plugs;
- (b) applying adhesive to the filter wrapper in register with the arranged plugs, so there is no adhesive in register with the spaces between the plugs;
- (c) gathering the wrapper and plugs together such that the adhesive will be in register with the plugs but not in register with the spaces between plugs;
- (d) inserting receptacles for an additive (e.g. a capsule, e.g. a frangible capsule) into spaces between the plugs of tobacco smoke filtering material (e.g. as the wrapper and plugs are gathered together);
- (e) securing the wrapper around the plugs of tobacco smoke filtering material (e.g. using further adhesive applied to the edge of the wrapper) to form a continuous rod of alternating wrapped plugs and cavities, such that no adhesive is present in the cavities; and optionally;
- (f) cutting the resulting continuous product rod to form individual filters or filter elements.

The method of production of the present invention allows for use of standard cellulose acetate tow items for example NWA (non-wrapped acetate) filtering plugs. It will be appreciated that other materials that are well known in the art may be used to form the tobacco smoke filter material, wrapper and receptacle for an additive.
The method of production of the present invention requires a combiner machine and an additional capsule inserter kit (known in the art). The filters are produced via the production of a multiple length rod. The machine tow processing is set to arrange plugs of cellulose acetate tow on to a filter wrapper (garniture) longitudinally at intervals so as to leave spaces between plugs. A segment anchorage adhesive is applied to filter wrapper at equivalent intervals to the plugs so there is no adhesive in the spaces between plugs. The wrapper and plugs are brought together ensuring adhesive is in register with the plugs but not in register with the spaces between plugs. The capsule inserter kit is then set to insert capsules into the spaces between the plugs of cellulose acetate tow by means of a capsule drum. A filter containing two or more capsules may also be produced. The wrapper, with adhesive applied to the edge, is gathered and secured around the plugs to form a continuous rod of alternating wrapped plugs and cavities, such that no adhesive is present in the cavities. The adhered wrapper forms a continuous rod of alternating wrapped plugs and cavities with one or more receptacles for an additive enclosed in each cavity. An optional step of cutting the resulting continuous product rod to form individual filters or filter elements may then be executed.
The continuous rod may be cut through each plug of tobacco smoke filtering material. Cutting may occur at any position through the plug of tobacco smoke filtering material to produce variations in size of the first and second plugs of tobacco smoke filtering material and cavity position within the longitudinally extending core. For example, cutting longitudinally through the centre of the plugs of tobacco smoke filtering material will create individual tobacco smoke filter or filter elements with first and second longitudinally extending rods of tobacco smoke filtering material of equal size surrounding a centrally located cavity. Cutting at other positions will create individual tobacco smoke filter or filter elements with first and second longitudinally extending rods of tobacco smoke filtering material of different size surrounding an off-centre cavity. The filter or filter element length will not be affected by variation in cutting, and the performance (e.g. the pressure drop) of the final filter will be consistent.
According to the present invention there is also provided a tobacco smoke filter or filter element comprising: a longitudinally extending core which includes first and second longitudinally extending rods of tobacco smoke filtering material, wherein the first rod of tobacco smoke filtering material is distanced longitudinally from the second rod of tobacco smoke filtering material; a wrapper engaged around the first and second longitudinally extending rods such that the wrapper defines a cavity between the first and second rods of tobacco smoke filtering material; and at least one receptacle for an additive located in the cavity, the receptacle being free to move within the cavity.
The present invention will now be illustrated by way of an example with reference to the accompanying drawing.

FIG. 1 shows a perspective view, not to scale, of a tobacco smoke filter or filter element according to an example of the invention.

FIG. 2 shows a cross-section, not to scale, view of FIG. 1 when cut along the filter's longitudinal axis.

FIG. 3 shows a birds-eye-view of a cross section, not to scale, of the of the method of production of a multiple length rod according to an example of the invention.

FIG. 4 shows a perspective view, not to scale, of a tobacco smoke filter or filter element according to a second example of the invention.

FIGS. 1 and 2 show a tobacco smoke filter or filter element of 27 mm length and 24.5 mm circumference comprising a longitudinally extending cylindrical core 1 which includes first and second longitudinally extending rods of tobacco smoke filtering material 2 and 3 in the form of NWA (non-wrapped acetate) crimped tow. The first rod of tobacco smoke filtering material 2 is distanced longitudinally from the second rod of tobacco smoke filtering material 3. Engaged around the first and second longitudinally extending rods 2, 3 (and the distance between) is a wrapper 4 of transparent air-permeable plugwrap which is held in place with an adhesive stuck seam along portions of its length. The wrapper 4 defines a cavity 5 of length 5 mm and diameter 7.8 mm between the first and second rods of tobacco smoke filtering material 2 and 3. A segment anchoring adhesive is applied to wrapper 4 in register with the first and second rods of tobacco smoke filtering material 2 and 3 (to hold rods 2 and 3 in place) but is not applied in register with the spaces between plugs, as such that no segment anchoring adhesive is present within the cavity 5. A receptacle for additive in the form of a frangible capsule 6 of diameter 3.5 mm, which includes a menthol flavouring agent, is fully enclosed within the cavity 5. Frangible capsule 6 has a diameter of less than 50% of the diameter of cavity 5. The void space in cavity 5 (e.g. the space not occupied by frangible capsule 6) is 88%. The dimensions of the frangible capsule 6 in relation to the dimensions of cavity 5 and the absence of adhesive within the cavity, mean that capsule 6 is free to move within the cavity 5. The wrapper 4 serves as a window into cavity 5 which may be used to identify the flavourant in the capsule 6 (e.g. a green capsule for menthol) and establish whether or not the capsule 6 has been broken. This wrapper 4 further differentiates the filter for anti-counterfeiting purposes. In other examples the wrapper 4 may be opaque with an opacity of 71% or more (measured according to ISO 2471:2008 Paper and board—Determination of opacity (paper backing)—Diffuse reflectance method).
It will be appreciated that the filter 1 may be joined to a wrapped tobacco rod to form a cigarette, by methods well known in the art. The filter may, for example, be joined to the wrapped tobacco rod by ring tipping [which engages around just the adjacent ends of the (wrapped) filter and rod to leave much of the filter wrap exposed]. The filter may, for example, be joined by a full tipping overwrap (which engages around the full filter length and the adjacent end of the tobacco rod).
FIG. 3 illustrates a birds-eye-view of a cross section of the of the method of production of a multiple length rod according to an example of the invention. The continuous rod of filters 7 comprises plugs of tobacco smoke filtering material 8, which are adhered to wrapper 9. No adhesive is present within the cavity 10 hence capsule 11 is able to move freely within the cavity. The continuous rod of filters 7 may be cut to create individual tobacco smoke filter or filter elements as in FIGS. 1 and 2 . It will be appreciated that cutting may occur at a range of positions through the plugs of tobacco smoke filtering material to create individual tobacco smoke filter or filter elements.
The method of production of the present invention requires a combiner machine and an additional capsule inserter kit (known in the art). The filters are produced via the production of a multiple length rod. The machine tow processing is set to arrange plugs of cellulose acetate tow 8 on to a filter wrapper 9 (garniture) longitudinally at intervals so as to leave spaces between plugs 8. A segment anchorage adhesive is applied to filter wrapper 9 at equivalent intervals to the plugs 8 so there is no adhesive in the spaces between plugs. Conventionally, segment anchorage gluing is a continual line of glue that hold the segments in place—so that when smoked the segment will not come out into the smokers mouth. The applicant has developed a method which uses pulses of spray adhesive to apply a discontinuous line of adhesive which is in register with the plugs but not in the cavity. The wrapper 9 and plugs 8 are brought together ensuring adhesive is in register with the plugs 8 but not in register with the spaces between plugs 8. The capsule inserter kit is then set to insert capsules 11 into the spaces between the plugs 8 of cellulose acetate tow by means of a capsule drum. The wrapper 9, with adhesive applied to the edge, is gathered and secured around the plugs 8 to form a continuous rod of alternating wrapped plugs 8 and cavities 10 (each cavity 10 containing a capsule 11), such that no adhesive is present in the cavities. The adhered wrapper forms a continuous rod of alternating wrapped plugs and cavities with one or more receptacles for an additive enclosed in each cavity. The resulting continuous product rod is cut to form individual filters or filter elements.
FIG. 4 shows a tobacco smoke filter or filter element of 27 mm length and 24.5 mm circumference comprising a longitudinally extending cylindrical core 101 which includes first and second longitudinally extending rods of tobacco smoke filtering material 102 and 103 in the form of wrapped acetate crimped tow. The first rod of tobacco smoke filtering material 102 is distanced longitudinally from the second rod of tobacco smoke filtering material 103. Engaged around the first and second longitudinally extending rods 102, 103 (and the distance between) is an opaque wrapper 104 of air-permeable plugwrap with an opacity of 71% or more (measured according to ISO 2471:2008 Paper and board—Determination of opacity (paper backing)—Diffuse reflectance method), which is held in place with an adhesive stuck seam along portions of its length. The wrapper 104 defines a cavity 105 of length 5 mm and diameter 7.8 mm between the first and second rods of tobacco smoke filtering material 102 and 103. A segment anchoring adhesive is applied to wrapper 104 in register with the first and second rods of tobacco smoke filtering material 102 and 103 (to hold rods 102 and 103 in place) but is not applied in register with the spaces between plugs, as such that no segment anchoring adhesive is present within the cavity 105. Engaged around the wrapper 104 is tipping paper 107, used to join the tobacco smoke filter or filter element 101 to a wrapped tobacco rod (although not shown in FIG. 4 ). A receptacle for additive in the form of a frangible capsule 106 of diameter 3.5 mm, which includes a menthol flavouring agent, is fully enclosed within the cavity 105. Frangible capsule 106 has a diameter of less than 50% of the diameter of cavity 105. The void space in cavity 105 (e.g. the space not occupied by frangible capsule 106) is 88%. The dimensions of the frangible capsule 106 in relation to the dimensions of cavity 105 and the absence of adhesive within the cavity 105, mean that capsule 106 is free to move within the cavity 105.

EXAMPLE 1

An experiment was performed in order to measure the effect the capsule in the cavity had on the menthol yield in the smoke. The filter A (according to FIG. 4 ) was made by the methods described above. Filter A was tested against a conventional filter B with a capsule embedded within the tobacco smoke filtering material well known in the art. The capsule of filter A and the capsule of filter B were crushed prior to smoking to release menthol flavourant.
The average menthol smoke yield smoke for filters A and B were measured by methods well known in the art (ISO 13110:2012 specifies a method for the gas-chromatographic determination of menthol in the total particulate matter (TPM) of mentholated cigarette smoke condensates). The results are illustrated in Table 1. The pad measurement data indicates the yield of menthol in the smoke.

	TABLE 1

	Menthol on pad/mg

	Filter A	1.19
	Filter B	0.75

The applicants have surprisingly found that positioning of a free moving capsule within the cavity supplies a greater yield of flavourant to the user compared to a capsule embedded within the tobacco smoke filtering material. The menthol yield in the smoke is higher when the crushed capsule is positioned within the cavity (and is free to move within the cavity) thus the user experiences increased flavour delivery.

Claims

1. A tobacco smoke filter or filter element comprising:

a longitudinally extending core which includes first and second longitudinally extending rods of tobacco smoke filtering material, wherein the first longitudinally extending rod of tobacco smoke filtering material is distanced longitudinally from the second longitudinally extending rod of tobacco smoke filtering material;

a wrapper engaged around the first and second longitudinally extending rods of tobacco smoke filtering material such that the wrapper defines a cavity between the first and second longitudinally extending rods of tobacco smoke filtering material; and

at least one receptacle for an additive located in the cavity, wherein a maximum width or diameter of the at least one receptacle for the additive is less than half a maximum diameter of the cavity and a void space remaining in the cavity is greater than 50% of a volume of the cavity, the at least one receptacle being free to move within the cavity.

2. The tobacco smoke filter or filter element according to claim 1, wherein the at least one receptacle for the additive is a capsule.

3. The tobacco smoke filter or filter element according to claim 1, wherein the at least one receptacle for the additive includes the additive in the form of a flavourant.

4. The tobacco smoke filter or filter element according to claim 1, wherein the void space remaining in the cavity is 51 to 90% of the volume of the cavity.

5. The tobacco smoke filter or filter element according to claim 1, wherein the longitudinally extending core is a substantially cylindrical core.

6. The tobacco smoke filter or filter element according to claim 1, wherein the tobacco smoke filtering material of the first and/or second longitudinally extending rod of tobacco smoke filtering material comprises a natural or synthetic filamentary tow.

7. The tobacco smoke filter or filter element according to claim 1, wherein the tobacco smoke filtering material includes carbon.

8. The tobacco smoke filter or filter element according to claim 1, wherein the tobacco smoke filtering material of the first longitudinally extending rod of tobacco smoke filtering material and the tobacco smoke filtering material of the second longitudinally extending rod of tobacco smoke filtering material are different.

9. The tobacco smoke filter or filter element according to claim 1, wherein the longitudinally extending core is of perimeter or circumference 14 to 28 mm.

10. The tobacco smoke filter or filter element according to claim 1, wherein the wrapper is transparent.

11. The tobacco smoke filter or filter element according to claim 1, wherein the cavity is of length 3.5 mm to 32 mm.

12. The tobacco smoke filter or filter element according to claim 1, wherein a region of the cavity is free of adhesive.

13. The tobacco smoke filter or filter element according to claim 1, wherein the at least one receptacle for the additive is of width 2 to 5 mm.

14. The tobacco smoke filter or filter element according to claim 1, wherein a diameter of the longitudinally extending core is at least 0.7 mm greater than the maximum width of the at least one receptacle for the additive.

15. A smoking article comprising the tobacco smoke filter or the tobacco smoke filter including the filter element according to claim 1, joined to a wrapped tobacco rod with one end of the tobacco smoke filter towards the wrapped tobacco rod.

16. A multiple rod comprising a plurality of tobacco smoke filters or filter elements according to claim 1 integrally joined end-to-end.

17. The tobacco smoke filter or filter element according to claim 1, wherein the at least one receptacle for the additive supplies a greater yield of flavourant to a user.

18. The tobacco smoke filter or filter element according to claim 1, wherein the cavity has a diameter from 5 mm to 10 mm.

19. The tobacco smoke filter or filter element according to claim 1, wherein the wrapper is opaque with an opacity of 71% or more.

20. A method of making a tobacco smoke filter or filter element, the method comprising steps of:

(a) arranging plugs of tobacco smoke filtering material on a filter wrapper longitudinally at intervals so as to leave spaces between the plugs;

(b) applying adhesive to the filter wrapper in register with the arranged plugs, so there is no adhesive in register with the spaces between the plugs;

(c) gathering the wrapper and the plugs together such that the adhesive will be in register with the plugs but not in register with the spaces between the plugs;

(d) inserting receptacles for an additive into the spaces between the plugs of tobacco smoke filtering material; and

(e) securing the wrapper around the plugs of tobacco smoke filtering material to form a continuous rod of alternating wrapped plugs and cavities, such that no adhesive is present in the cavities.

21. The method according to claim 20 in which alternating plugs are made of first and second filtering materials.

22. The method according to claim 20 in which two or more receptacles are inserted into the spaces between the plugs of tobacco smoke filtering material.

23. A tobacco smoke filter or filter element comprising:

at least one receptacle for an additive located in the cavity, the at least one receptacle being free to move within the cavity.

24. The method according to claim 20, further including:

cutting the resulting continuous product rod to form individual filters or filter elements.