Tobacco smoke filter

Abstract

A tip for a smoking article such as a cigar is disclosed. The tip comprises a longitudinally extending element comprising a plurality of bicomponent fibers which define at least one channel extending longitudinally of the element.

Claims

1. A tip for a smoking article, the tip comprising a longitudinally extending element comprising a plurality of bicomponent fibres which define at least one channel extending longitudinally of the element, wherein each of the at least one channel extends along the full length of the element, wherein the plurality of bicomponent fibres have a bonded fibre density of 0.20 to 0.44 g/cc, and wherein the longitudinally extending element is smoke impermeable.

2. A tip according to claim 1 wherein the longitudinally extending element is cylindrical and/or wherein the longitudinally extending element is of annular cross section.

3. A tip according to claim 1 wherein the plurality of bicomponent fibres define two or more channels extending longitudinally of the element.

4. A tip according to claim 1 wherein the longitudinally extending element is of uniform cross section.

5. A tip according to claim 1 wherein the longitudinally extending element has a hardness of 96%.

6. A tip according to claim 1 wherein the bicomponent fibres include a core of a first component surrounded by a sheath of a second component.

7. A tip according to claim 1 which further comprises a wrapper engaged around the longitudinally extending element.

8. A tip according to claim 1 wherein the cross-sectional area of each of the at least one channel is 2.5 to 25% of the cross-sectional area of the longitudinally extending element.

9. A tip according to claim 1 wherein each of the at least one channel is of circular cross section.

10. A tip for a smoking article, the tip comprising a wrapper engaged around a longitudinally extending element comprising a plurality of bicomponent fibres which define at least one channel extending longitudinally of the element; wherein at least one end of the wrapper extends beyond the end of the element around which the wrapper is engaged, to define a cavity at the end of the tip, wherein each of the at least one channel extends along a full length of the element, and wherein the plurality of bicomponent fibres have a bonded fibre density of 0.20 to 0.44 g/cc, and wherein the longitudinally extending element is smoke impermeable.

11. A tobacco smoke filter or filter element comprising: an upstream filter element including a tobacco smoke filtering material; and a downstream tip comprising a tip according to claim 1.

12. A tobacco smoke filter or filter element comprising: an upstream filter element including a tobacco smoke filtering material; and a downstream tip comprising a longitudinally extending element comprising a plurality of bicomponent fibres which define at least one channel extending longitudinally of the element, wherein each of the at least one channel extends along the full length of the longitudinally extending element of the downstream tip, and wherein the plurality of bicomponent fibres have a bonded fibre density of 0.20 to 0.44 g/cc.

13. A tobacco smoke filter or filter element according to claim 12, wherein the upstream element further comprises a frangible capsule or frangible microcapsules.

14. A tobacco smoke filter or filter element according to claim 12, which further comprises a wrapper engaged around the upstream filter element and downstream tip.

15. A tobacco smoke filter or filter element according to claim 14 comprising a further wrapper which extends beyond the end of the upstream filter element around which the wrapper is engaged, to define a cavity at the upstream end of the filter or filter element.

16. A tip according to claim 10, wherein the wrapper is printed or coated on an outer surface thereof; and/or wherein the wrapper is hydrophobic.

17. A tobacco smoke filter or filter element according to claim 14, wherein the wrapper is printed or coated on an outer surface thereof, and/or wherein the wrapper is hydrophobic.

18. A smoking article comprising a tip according to claim 1, the tip being joined to a wrapped tobacco rod with one end of the tip towards the tobacco rod.

19. A tobacco smoke filter or filter element according to claim 12, the filter or filter element being joined to a wrapped tobacco rod with one end of the tip towards the tobacco rod.

20. A tip according to claim 1 wherein no smoke can pass through walls of the longitudinally extending element.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The present invention will now be illustrated with reference to the following Examples and the attached drawing in which FIG. 1 schematically illustrates (not to scale) a tip according to an example of the invention.

DETAILED DESCRIPTION

(2) FIG. 1 shows a tip for a smoking article, according to an example of the invention. The tip (1) comprises a longitudinally extending element (2) of length 30 mm which is an annulus of outer diameter 10 mm, and which is formed from a plurality of bicomponent fibres. The bicomponent fibres which form the inner walls of the annular longitudinally extending element (2) define a single hollow cylindrical channel (3) of circular cross section which extends longitudinally through the element. The single hollow cylindrical channel (3) has a circular cross section of diameter 3 mm (not shown to scale). A wrapper (4) of plugwrap paper is engaged around the longitudinally extending element (2).

(3) The annular element (1) is formed using the process described in U.S. Pat. No. 5,607,766. A nonwoven web comprising melt blown bicomponent fibres having a polypropylene core surrounded by a sheath of polyethylene terephthalate was made. This web was formed into an annular rod using apparatus similar to that known for the manufacture of plasticized cellulose acetate cigarette filter elements. The annular rod was then wrapped in a non-porous plugwrap paper, again as outlined in U.S. Pat. No. 5,607,766. The annular rod so produced was cut into discrete product rods, in this case of length 120 mm, which were then each cut into four individual tips (1) of 30 mm length.

(4) The mean weight of each 120 mm product rod was 2.6 g. This gave a bonded fibre density in the longitudinally extending element (2) of 0.30 g/cc, which is around double the density of conventional porous cigarette filters. This higher density ensures that the longitudinally extending element (2) does have any filtering effect and provides sufficient hardness to the final tip (1). The hardness of the tip was around 99% [as measured on a Filtrona Hardness Tester (Manual) Model DHT200 (Fidus Instrument Co., Richmond, Va.)]; distinctly harder than conventional cigarette filter tips (e.g. maximum 95% hardness).

(5) As can be seen in FIG. 1, the tip (1) is connected to a wrapped tobacco column (5) of a cigar having the same diameter as tip (1), to provide a smoking article (cigar) of the invention. The tip (1) is joined to the wrapped tobacco rod by ring tipping [which engages around just the adjacent ends of the wrapped tip and rod to leave much of the filter wrap exposed (ring tipping not shown), as is well known in the art.