TOBACCO SMOKE FILTER

Abstract

A stand alone tobacco smoke filter or filter element for use with a smoking article comprising a wrapper engaged around a longitudinally extending core of tobacco smoke filtering material, wherein at least one end of the wrapper extends beyond the end of the core around which it is engaged, to define a cavity at the end of the filter which faces the smoking article in use.

Claims

1. A method of forming a smoking product, the method comprising: providing a stand-alone tobacco smoke filter or filter element comprising a wrapper engaged around a longitudinally extending core of tobacco smoke filtering material; providing a smoking article; extending at least one end of the wrapper beyond an end of the core around which the wrapper is engaged to define a cavity at an end of the filter or filter element; and inserting the smoking article into the cavity; wherein the wrapper is paper of basis weight from 30 to 80 g/m.sup.2; and wherein the smoking article has a circumference of 16 to 17 mm.

2. The method according to claim 1, wherein the cavity is of a length sufficient to provide a good interference fit between a radially inner face of the wrapper which defines the cavity and an outer face of the smoking article.

3. The method according to claim 1, wherein the end of the wrapper extends beyond the end of the core around which the wrapper is engaged by a length of 3 to 14 mm.

4. The method according to claim 1, wherein the at least one end of the wrapper is a first wrapper end and the end of the core around which the first wrapper end of the wrapper is engaged is a first core end, a second wrapper end of the wrapper extending beyond a second core end of the core to define a cavity at each end of the filter.

5. The method according to claim 4, wherein the first and second wrapper ends of the wrapper extend beyond the first and second core ends of the core by a length of 3 to 14 mm.

6. The method according to claim 5, wherein the first and second wrapper ends of the wrapper extend beyond the first and second core ends of the core by a length of 5 to 12 mm.

7. The method according to claim 1, wherein the at least one end of the wrapper is a first wrapper end, the end of the core around which the first wrapper end of the wrapper is engaged is a first core end, and the wrapper has a second wrapper end flush or substantially flush with a second core end of the core.

8. The method according to claim 1, wherein the wrapper is printed or coated with a pattern and/or the wrapper is hydrophobic and/or has a hydrophobic coating and/or further includes a further wrapper and/or includes perforations around a periphery thereof and/or the filtering material is a cellulose acetate tow.

9. The method according to claim 1, wherein the smoking article is a tapered smoking article.

10. The method according to claim 1, further comprising a flavoring agent.

11. The method according to claim 1, wherein the smoking article is a kretek cigarette.

12. The method according to claim 1, wherein the wrapper is a single wrapper.

13. The method according to claim 1, wherein the paper is of basis weight of about 50 g/m.sup.2.

14. The method according to claim 1, further including engaging the wrapper around at least a part of a smoking article placed adjacent to and in register with the longitudinally extending core of tobacco smoke filtering material, wherein the end of the wrapper extends beyond the end of the core around which the wrapper is engaged by a length of 3 to 14 mm.

15. The method according to claim 1, further including engaging the wrapper around at least a part of a smoking article placed adjacent to and in register with the longitudinally extending core of tobacco smoke filtering material, wherein the at least one end of the wrapper is a first wrapper end and the end of the core around which the first wrapper end of the wrapper is engaged is a first core end, a second wrapper end of the wrapper extending beyond a second core end of the core to define a cavity at each end of the filter.

16. A method of forming a smoking product, the method comprising: providing a stand-alone tobacco smoke filter or filter element comprising a longitudinally extending core of tobacco smoke filtering material and a wrapper which is attached thereto; providing a smoking article; engaging the wrapper around the longitudinally extending core of tobacco smoke filtering material and at least a part of a smoking article placed adjacent thereto and in register therewith; fixing the wrapper in place when the wrapper is engaged around the longitudinally extending core of tobacco smoke filtering material and the part of the smoking article placed adjacent thereto to thereby hold the core of tobacco smoke filtering material in register with the smoking article; wherein the wrapper is paper of basis weight from 30 to 80 g/m.sup.2; wherein the smoking article has a circumference of 16 to 17 mm; and wherein the step of engaging the wrapper around the longitudinally extending core of tobacco smoke filtering material and at least the part of the smoking article placed adjacent thereto and in register therewith comprises: extending at least one end of the wrapper beyond an end of the core around which the wrapper is engaged to define a cavity at an end of the filter or filter element; and inserting the smoking article into the cavity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will now be illustrated with reference to the following Examples and the attached drawings.

[0034] FIG. 1 schematically illustrates a recess filter according to an example of the invention in use.

[0035] FIG. 2 schematically illustrates a recess filter according to another example of the invention.

[0036] FIG. 3 illustrates a stand-alone filter according to a further example of the invention and its use.

DETAILED DESCRIPTION

[0037] FIG. 1 shows an assembled cigarette, not to scale, incorporating a filter according to an example of the invention. The filter tip comprises a cylindrical plug 1 of cellulose acetate wrapped in a plugwrap (not shown) of 27 g/m.sup.2 weight. The length of this plug (dimension x) is 18 mm. The tip is overwrapped in a stiff plugwrap 2 of 100 g/m.sup.2 weight that extends beyond one end of the core around which it is engaged, to define a tubular cavity, or hollow tube 3, at that end of the filter. The stiff plugwrap has been printed on its outer surface with a cork effect. The length of hollow tube 3 (dimension y) is 9 mm, which corresponds to the length of the recess, thereby giving an overall tip length of 27 mm. The internal diameter of the tube 3 (dimension z) is 8 mm, corresponding to a circumference of 25 mm. A non-filtered tapered kretek cigarette 4 is inserted into the tube. The outer circumference of the kretek at around 7 mm from its narrower end is around 25 mm. Thus, a good interference fit between the tip and the kretek is achieved.

[0038] FIG. 2 shows a filter tip according to a further example of the invention. The filter tip comprises a plug 3 of cellulose acetate wrapped in a plugwrap (not shown) of 27 g/m.sup.2 weight. The length of this plug is 11 mm. The tip is overwrapped in a stiff plugwrap 2 of 100 g/m.sup.2 weight that extends beyond the plug in both directions to form hollow tubes 1a and 1b each of length 8 mm. The stiff plugwrap has been printed on its outer surface with a cork effect. The overall tip length is 27 mm and the internal diameter of each tubular section (recess) is 8 mm. The smoker is able to insert a non-filtered tapered smoking article, e.g. kretek, into either end of the tip, corresponding to a circumference of 25 mm.

[0039] In the example tips shown in FIGS. 1 and 2, the (or each) radially inner face of the plugwrap 2 which extends beyond the end of the plug around which it is engaged to form the hollow tubes (3 in FIG. 1, 1a, 1b in FIG. 2) may optionally have an adhesive, for example a contact adhesive, applied thereto. It will be appreciated that the use of an adhesive may be required to hold e.g. a non-tapered smoking article in place, if the interference fit between the untapered article and the inner face of the recess alone is insufficient. Adhesive may be applied to the (e.g. inner face of the) wrapper by methods well known in the art.

[0040] FIG. 3 shows filter tip 30 according to a still further example of the invention. The filter tip 30 comprises a core in the form of a cylindrical plug 31 of cellulose acetate attached to a wrapper 32 formed of a sheet of plugwrap of 45 g/m.sup.2 weight. As seen in FIG. 3, the wrapper 32 is a rectangle of plugwrap which is longer that the plug 31 in the longitudinal direction of the plug. One end of the wrapper 32 is substantially flush with one end 33 of the plug 31, while the other end of the wrapper 32 extends beyond the other end 34 of plug 31. The wrapper is attached to the plug 31 with adhesive along the portion 35 of the longitudinal edge 36 which is in contact with the plug 31; the wrapper has (further) fixing means in the form of gum along its other longitudinal edge 37 (along the edge which is opposite to the edge 36 which is attached to the core). It will be appreciated that for storage, packaging and sale etc the wrapper 32 may be wrapped or furled around the plug 31, but not fixed in engagement around the plug (i.e. the adhesive is not activated).

[0041] The filter tip 30 is used as shown in FIG. 3. The smoker takes the stand-alone filter tip 30 and unfurls the wrapper 32 from around the plug 31. He then places one end 46 of a smoking article (bidi, kretek, unfiltered cigarette) 45 adjacent to and in register with the end 34 of the plug 31 which has the overlapping wrapper. It will be appreciated that in general the end 46 of smoking article 45 will be butted up to and in contact with end 34 of plug 31. The wrapper 32 is then engaged (wrapped) around both plug 31 and the adjacent part of the smoking article 45 so as to encircle and surround both the plug and the end section of article 45. The fixing means (gum) on the inner face of edge 37 of the wrapper 32 is then fixed (stuck) to the radially outer face of the smoking article 45 and the plug 1 (or wrapper 32) to hold the wrapper 32 in engagement around plug 32 and smoking article 45, thereby providing a filtered smoking article.

[0042] It will be appreciated that the filters of the invention may be made by methods known in the art.