Smoking article with flow restrictor adapted to promote filter degradation

Abstract

A smoking article comprises a tobacco rod and a filter component. The filter component comprises a first filter segment of filtration material having a diameter measured perpendicular to a longitudinal direction of the filter, and a flow restrictor embedded in the filter segment. At least one cross sectional dimension of the flow restrictor, measured in a transverse direction of the filter segment, is at least about 50 percent of the diameter of the filter segment. The flow restrictor is made from an air-impermeable, non-compressible and water-soluble or water-dissolvable material. Further, the flow restrictor comprises a composition that promotes degradation of the filtration material.

Claims

1. A smoking article comprising a tobacco rod and a filter component, the filter component comprising: a filter segment of filtration material having a diameter measured perpendicular to a longitudinal direction of the filter; and a flow restrictor embedded in the filter segment; wherein at least one cross sectional dimension of the flow restrictor, measured in a transverse direction of the filter segment, is at least about 50 percent of the diameter of the filter segment; wherein the flow restrictor is made from an air-impermeable, non-compressible and water-soluble or water-dissolvable material; and wherein the flow restrictor comprises a composition that promotes degradation of the filtration material; wherein the flow restrictor comprises a bead, the composition that promotes degradation of the filtration material at least partly coating the bead.

2. A smoking article according to claim 1, wherein the composition that promotes degradation of the filtration material comprises at least one of: one or more nutrients suitable for sustaining microbial growth; one or more compounds adapted to initiate or sustain enzymatic or acidic hydrolysis of the filtration material; one or more acids; one or more acid salts; and one or more bases.

3. A smoking article according to claim 2, wherein the one or more acid is selected from the group consisting of acetic, ascorbic, ascorbyl-2-phosphate, ascorbyl-2-sulfate, aspartic (aminosuccinic), cinnamic citric, folic, glutaric, lactic, malic (1-hydroxysuccinic), nicotinic (nician), oxalic, succinic, tartaric, boric, hydrochloric, nitric, phosphoric, sulphuric acid, and combinations thereof; or the one or more acid salt is selected from the group consisting of metal salts, where the metal is selected from aluminium, potassium, sodium or zinc, while the anion is selected from the group consisting of nitrates, dihydrogen phosphates, hydrogen phosphates, phosphates hydrogen sulphates, sulphates, and combinations thereof; or the one or more base is selected from the group consisting of metal hydroxides, calcium oxide (lime), urea, borax, sodium metasilicate, ammonium hydroxide, sodium carbonate, sodium phosphate tribasic, sodium hypochlorite, sodium hydrogen carbonate (sodium bicarbonate) and combinations thereof.

4. A smoking article according to claim 1, wherein the flow restrictor is surrounded on all sides by the filtration material.

5. A smoking article according to claim 1, wherein the flow restrictor is provided as a substantially spherical bead and the at least one cross sectional dimension of the bead measured in a transverse direction of the filter is the diameter of the substantially spherical bead.

6. A smoking article according to claim 1, wherein the flow restrictor is provided as a substantially cylindrical bead, the at least one cross sectional dimension of the bead measured perpendicular to a longitudinal direction of the filter being the diameter of the substantially cylindrical bead.

7. A smoking article according to claim 6, wherein the cylindrical bead has a length of less than about 90 percent of a length of the filter segment.

8. A smoking article according claim 1, wherein the flow restrictor has a compressive yield strength greater than about 8.0 kPa.

9. A smoking article according to claim 1, wherein the flow restrictor is at least about 6 millimeters from the downstream end of the filter.

10. A smoking article according to claim 1, comprising tipping material attaching the tobacco rod and the filter; wherein the tipping material includes a ventilation zone comprising perforations through the tipping material.

11. A smoking article according to claim 10, wherein the ventilation zone comprises at least one circumferential row of perforations located at least about 1 millimeter downstream of the centre of the flow restrictor.

12. A smoking article according to claim 4, wherein the flow restrictor is provided as a substantially spherical bead and the at least one cross sectional dimension of the bead measured in a transverse direction of the filter is the diameter of the substantially spherical bead, and the diameter of the substantially spherical bead is at least about 70 percent and less than about 95 percent of the diameter of the filter segment.

13. A smoking article according to claim 10, wherein the flow restrictor is provided as a substantially spherical bead surrounded on all sides by the filtration material, and the ventilation zone comprises at least one circumferential row of perforations located at least about 1 millimeter downstream of the centre of the flow restrictor.

Description

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

(2) FIG. 1 illustrates a side sectional view of a smoking article in accordance with the present invention;

(3) FIG. 2 illustrates a bar graph of change in weight over time for samples of a first embodiment (Example 1) of filters for smoking articles according to the present invention compared to filters according to the prior art;

(4) FIG. 3 illustrates a bar graph of change in volume over time for samples of a first embodiment (Example 1) of filters for smoking articles according to the present invention compared to filters according to the prior art;

(5) FIG. 4 illustrates a bar graph of change in weight over time for samples of a second embodiment (Example 2) of filters for smoking articles according to the present invention; and

(6) FIG. 5 illustrates a bar graph of change in volume over time for samples of a second embodiment (Example 2) of filters for smoking articles according to the present invention.

(7) FIG. 1 shows a smoking article 10 in accordance with the present invention. The smoking article 10 comprises a rod 12 of tobacco cut filler circumscribed by a wrapper 13. The tobacco rod 12 is attached at one end to an axially aligned filter component 14. A band of tipping paper 16 circumscribes the filter 14 and a portion of the wrapped rod 12 of tobacco to join the filter component and the tobacco rod.

(8) The filter component 14 comprises a filter segment 18 of filtration material circumscribed by a plug wrap 20 and having a diameter DF measured perpendicular to a longitudinal direction of the filter component 14. Further, the filter component 14 comprises a flow restrictor 22 embedded in the filter segment. In particular, the flow restrictor 22 is surrounded on all sides by the filtration material. A row of ventilation perforations 24 is provided through the tipping paper 16 at a location downstream of the flow restrictor 22.

(9) In the embodiment of FIG. 1, the flow restrictor 22 is provided as a substantially spherical bead having a diameter DR. The diameter DR is about 80 percent of the diameter DF of the filter segment 18.

(10) The flow restrictor comprises a composition that promotes degradation of the filtration material. In practice, the flow restrictor is used as a chamber to incorporate substances which will enhance cellulose acetate biodegradation according to one of the mechanisms described above.

EXAMPLES

(11) Degradability of filters of smoking articles according to the invention was assessed in accordance with the CORESTA testing protocol for assessing the degradation of cigarette butts under natural conditions as described in Deutsch, Lance JCigarette Butt Degradability Task Force. Final ReportAugust, 2000CORESTAhttp://legacy.library.ucsf.edu/tid/qtg33a00.

(12) In more detail, several substantially identical specimens of a cigarette butt were placed outdoors in two separate 6-compartment metal cages arranged on concrete and on soil, respectively. For the purposes of the protocol, a cigarette butt is defined as the filter with its plug wrap plus the tipping overwrap. 10 specimens were placed in each compartment, and each compartment was provided with a tag for identification of the specimen type. The specimens were exposed to the action of the weather for a period of 6 months. Weather conditions, i.e. sun radiation, wind, precipitation, humidity and temperature were monitored and recorded for the whole duration of the tests. The specimens were examined at the start of the test. Specimens were collected and examined at predetermined time intervals, after 1, 3 and 6 months of exposure to weather conditions. In particular, the weight and bulk volume of the samples were measured in order to assess cellulose degradation over time. Further, visual comparisons were carried out on the samples.

Comparative Example

(13) As a reference, samples of butts from Marlboro Gold cigarettes were tested for cellulose degradation. These filters contain a conventional segment of cellulose acetate and no agent capable of promoting cellulose degradation.

Example 1

(14) A first set of cigarette butts in accordance with the present invention were prepared by including in a segment of cellulose acetate circumscribed by a paper wrapper and by tipping paper a restrictor bead comprising citric acid as the agent capable of promoting cellulose degradation. With the sole exception of the restrictor bead, the same materials found in butts of Marlboro Gold cigarettes were used. Each mouthpiece contained a restrictor bead with a core containing 70 percent by weight citric acid and 30 percent by weight microcrystalline cellulose and coated with ethylcellulose. The ethylcellulose coating accounted for 15 percent of the overall weight of the bead. Thus, the overall composition of the bead was 59.5 percent citric acid, 25.5 percent microcrystalline cellulose and 15 percent by weight ethylcellulose. The overall weight of the restrictor was of about 45 mg. The overall weight of the cigarette butt excluding the restrictor was about 202 mg. Thus, the composition promoting degradation of the filtration material accounted for about 0.22 mg per mg of combined weight of the filtration segment. Specimens prepared in accordance with Example 1 were placed in two separate 6-compartment metal cages arranged on concrete and on soil, respectively. 10 specimens were placed in each compartment. The specimens were exposed to the action of the weather for a period of 6 months from January to June 2014 (tests were carried out in Ghent, Belgium).

Example 2

(15) A second set of cigarette butts in accordance with the present invention were prepared by including in a segment of cellulose acetate circumscribed by a paper wrapper and by tipping paper a restrictor bead comprising sodium bisulphate as the agent capable of promoting cellulose degradation. With the sole exception of the restrictor bead, the same materials found in butts of Marlboro Gold cigarettes were used. Each mouthpiece contained a restrictor bead with a core containing 80 percent by weight sodium bisulphate and 20 percent by weight microcrystalline cellulose and coated with ethylcellulose. The ethylcellulose coating accounted for 15 percent of the overall weight of the bead core. Thus, the overall composition of the bead was 68 percent by weight citric acid, 17 percent by weight microcrystalline cellulose and 15 percent by weight ethylcellulose. The overall weight of the restrictor was of about 26 mg. The overall weight of the cigarette butt excluding the restrictor was about 202 mg. Thus, the composition promoting degradation of the filtration material accounted for about 0.13 mg per mg of combined weight of the filter segment. Specimens prepared in accordance with Example 2 were placed in two separate 6-compartment metal cages arranged on concrete and on soil, respectively. 10 specimens were placed in each compartment. The specimens were exposed to the action of the weather for a period of 6 months from February to July 2014 (tests were carried out in Ghent, Belgium).

(16) Weight Measurements

(17) FIGS. 2 and 4 illustrate, by means of bar graphs, the change in weight over time measured for the cigarette butts of Examples 1 and 2 and the Comparative Example.

(18) As can be seen from FIG. 2, the reduction in weight for the cigarette butts of Example 1 is always greater than the reduction in weight for the reference cigarette butts of the Comparative Example. In particular, after 6 months, a reduction in weight of about 40 percent was measured for the cigarette butts of Example 1 kept on soil, whereas a reduction in weight of less than 20 percent was measured for the cigarette butts of the Comparative Example kept on soil. As concerns samples kept on concrete, after 6 months a reduction in weight of more than 20 percent was measured for the cigarette butts of Example 1, whereas for the cigarette butts of the Comparative Example the reduction in weight was found to be slightly less than 10 percent. Thus, the experimental data would appear to suggest that, in general, the cellulose acetate degradation rate was approximately doubled for the cigarette butts of Example 1.

(19) As regards the filters of Example 2, as can be inferred from FIG. 4, the reduction in weight is also consistently greater than the reduction in weight measured for the reference cigarette butts of the Comparative Example, although the effect is less evident than with the cigarette butts of Example 1.

(20) Volume Measurements

(21) FIGS. 3 and 5 illustrate, by means of bar graphs, the change in weight over time measured for the cigarette butts of Examples 1 and 2 and the Comparative Example.

(22) As can be seen from FIG. 3, the reduction in volume for the cigarette butts of Example 1 is always greater than the reduction in weight for the reference cigarette butts of the Comparative Example. In particular, after 6 months, a reduction in volume of about 20 percent was measured for the cigarette butts of Example 1 kept on soil, whereas a reduction in weight of about 8 percent was measured for the cigarette butts of the Comparative Example kept on soil. As concerns samples kept on concrete, after 6 months a reduction in weight of about 5 percent was measured for the cigarette butts of Example 1, whereas for the cigarette butts of the Comparative Example the reduction in volume was found to be just about 2 percent. Thus, the experimental data would appear to confirm that, in general, the cellulose acetate degradation rate was approximately doubled for the cigarette butts of Example 1.

(23) As regards the cigarette butts of Example 2 (strong chemistry), as can be inferred from FIG. 5, the reduction in volume is also consistently greater than the reduction in volume measured for the reference cigarette butts of the Comparative Example although the effect is less evident than with the cigarette butts of Example 1.