TOBACCO SMOKE FILTER

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.

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: 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, 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.

Description

[0032] FIG. 1 shows a perspective view, not to scale, of a tobacco smoke filter or filter element according to an example of the invention.

[0033] FIG. 2 shows a cross-section, not to scale, view of FIG. 1 when cut along the filter's longitudinal axis.

[0034] 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.

[0035] 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.

[0036] 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).

[0037] 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).

[0038] 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.

[0039] 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.

[0040] 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

[0041] 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.

[0042] 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-US-00001 TABLE 1 Menthol on pad/mg Filter A 1.19 Filter B 0.75

[0043] 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.