Smoking article filter including degradable filter component

Abstract

A filter for a smoking article includes a filter component formed from a solution of cellulose acetate and a degradable polymer in aceton, the degradable polymer being soluble in acetone and degrading in the presence of water. In a first aspect of the invention, the filter component is a filter segment (16) formed of a plurality of fibers formed from the degradable solution. In a second aspect of the invention, the filter component is a wrapper (39) circumscribing at least a segment of the filter.

Claims

1. A filter for a smoking article, the filter including a filter component formed from a solution of cellulose acetate and a degradable polymer in acetone, the degradable polymer being soluble in acetone and degrading in the presence of water, wherein the degradable polymer is polylactic-co-glycolic acid.

2. A filter according to claim 1 wherein the filter component is a segment of fibrous filtration material comprising a plurality of fibres formed of the solution comprising cellulose acetate and the degradable polymer.

3. A filter according to claim 1 wherein the solution of cellulose acetate and the degradable polymer in acetone comprises between 10 percent and 75 percent by weight of the degradable polymer, based on total dry weight.

4. A filter according to claim 2 wherein the segment of fibrous material further comprises at least one plasticiser applied to the plurality of fibres.

5. A filter according to claim 4 wherein the plasticiser is selected from the group consisting of triacetin, triethyl citrate and polyethylene glycol.

6. A filter according to claim 2 comprising a plurality of spun fibres of the solution comprising cellulose acetate and the degradable polymer.

7. A filter according to claim 6 wherein the fibres are formed by dry solvent spinning.

8. A filter according to claim 2 further comprising at least one of a rod end segment upstream of the segment of fibrous filtration material and a mouth end segment downstream of the fibrous filter segment.

9. A filter according to claim 1 wherein the filter component is a wrapper formed of the solution comprising cellulose acetate tow and the degradable polymer, the wrapper circumscribing at least a portion of the filter.

10. A filter according to claim 9 wherein the composition forming the wrapper comprises between 10 percent and 50 percent by weight of the degradable polymer, based on total dry weight.

11. A filter according to claim 9 wherein the wrapper is substantially transparent.

12. A filter according to claim 11 wherein the substantially transparent wrapper is a plug wrap and wherein the filter further comprises an outer wrapper overlying the plug wrap, the outer wrapper including a cut-out.

13. A smoking article comprising: an aerosol-forming substrate; and a mouthpiece secured in axial alignment with the aerosol-forming substrate, the mouthpiece comprising a filter according to claim 1.

14. A smoking article according to claim 13 comprising a tobacco rod attached to the filter.

Description

(1) The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 shows a smoking article comprising a filter in accordance with the first aspect of the present invention with the filter unwrapped; and

(3) FIG. 2 shows a smoking article comprising a filter in accordance with the second aspect of the present invention with the filter unwrapped.

(4) The filter cigarette 10 shown in FIG. 1 comprises a wrapped rod 12 of tobacco cut filler which is attached at one end to an axially aligned filter 14 according to the first aspect of the invention comprising a single filter segment 16 which has been wrapped with a plug wrap 18. The wrapped tobacco rod 12 and the filter 14 are joined by an outer wrapper 20 formed of tipping paper, which circumscribes the entire length of the filter 14 and an adjacent portion of the tobacco rod 12.

(5) The filter segment 16 comprises a plurality of fibres formed of a composition comprising 50 percent by weight of cellulose acetate and 50 percent by weight of polylactic-co-glycolic acid. A plasticiser comprising triacetin has been applied to the fibres in the conventional manner.

(6) The plurality of fibres are formed in a dry solvent spinning process as described above and the filter segment 16 may be produced from the fibres in a conventional manner. To form the filter cigarette 10 the filter 14 is produced and then joined to the wrapped tobacco rod 12, which is produced in a conventional manner, by the tipping paper 16 using known filter cigarette making equipment.

(7) FIG. 2 shows a filter cigarette 30 comprising a wrapped rod 32 of tobacco cut filler which is attached to an axially aligned filter 34 in accordance with the second aspect of the invention comprising three filter segments in abutting end-to-end relationship: a mouth end segment 36, distant from the wrapped tobacco rod 32; a flavour release segment 38, located upstream of the mouth end segment 36; and a rod end segment 40 adjacent to and abutting the wrapped tobacco rod 32 and located upstream of the first flavour release segment 38.

(8) The mouth end segment 36 comprises a plug of cellulose acetate tow of low filtration efficiency. The flavour release segment 38 comprises a plug of cellulose acetate tow through which particles of a suitable flavourant have been dispersed, such as cut peppermint leaf. The rod end segment 40 comprises a plug of cellulose acetate tow of medium to low filtration efficiency loaded with an additive, such as activated carbon. The mouth end segment 36, the flavour release segment 38 and the rod end segment 40 are each wrapped with a segment plug wrap 37, 39, 41. The plug wrap 39 of the flavour release segment 38 is formed of a substantially transparent sheet material comprising 80 percent by weight cellulose acetate and 20 percent by weight polylactic-co-glycolic acid.

(9) The wrapped tobacco rod 32 and the wrapped filter 34 are joined by an outer wrapper 42 formed of tipping paper, which circumscribes the entire length of the filter 34 and an adjacent portion of the tobacco rod 32. The outer wrapper 42 comprises a circular cut-out portion 44 having a diameter of approximately 5 mm which is positioned over the flavour release segment 38, approximately halfway along the length of the segment. The underlying substantially transparent plug wrap 39 is exposed through the cut-out portion 44 in the outer wrapper 42 and an area of the flavour release segment 38 including the cut peppermint leaf is therefore visible through the cut-out portion 44.

(10) To produce the multi-component filter 34 of the filter cigarette 30 shown in FIG. 2, separate continuous rods comprising multiple units of each segment 36, 38, 40 of the multi-component filter. 34 are produced in a known manner. The segments 36, 40 are wrapped in a conventional plug wrap material and the segment 38 is wrapped in a transparent plug wrap formed of a composition comprising cellulose acetate and polylactic-co-glycolic acid. The assembled filter is joined to the wrapped tobacco rod 32 by the outer wrapper 42 with the pre-formed cut-out portion 44.