Multi-component filter providing multiple flavour enhancement

Abstract

A multi-component filter for a smoking article comprises: a mouth end segment; a first flavour release segment comprising plant leaf upstream of the mouth end segment; and a second flavour release segment comprising filtration material and a flavourant upstream of the first flavour release segment. The resistance to draw of the second flavour release segment is greater than the resistance to draw of the first flavour release segment and the resistance to draw of the second flavour release segment is greater than the resistance to draw of the mouth end segment. The multi-component filter preferably further comprises a rod end segment comprising filtration material upstream of the second flavour release segment, which has a lower resistance to draw than the second flavour release segment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 shows a side view of a filter cigarette comprising a tobacco rod and a multi-component filter according to a first preferred embodiment of the invention with portions thereof broken away to illustrate interior details of the multi-component filter;

FIG. 2 shows a side view of a filter cigarette comprising a tobacco rod and a multi-component filter according to a second embodiment of the invention with portions thereof broken away to illustrate interior details of the multi-component filter;

FIG. 3 shows a side view of a filter cigarette comprising a tobacco rod and a multi-component filter according to a third embodiment of the invention with portions thereof broken away to illustrate interior details of the multi-component filter; and

FIG. 4 shows a two-stage combining process for forming a multi-component filter according to the first preferred embodiment of the invention shown in FIG. 1.

The cigarettes according to the first, second and third embodiments of the invention shown in FIGS. 1, 2 and 3, respectively, have several components in common; these components have been given the same reference numerals throughout.

DETAILED DESCRIPTION

Each cigarette generally comprises an elongate, cylindrical wrapped tobacco rod 2 attached at one end to an axially aligned, elongate, cylindrical, multi-component filter 4. The wrapped tobacco rod 2 and the multi-component filter 4 are joined in a conventional manner by tipping paper 6, which circumscribes the entire length of the multi-component filter and an adjacent portion of the wrapped tobacco rod 2. To ventilate mainstream smoke produced during combustion of the wrapped tobacco rod 4 with ambient air, a plurality of annular perforations 8 are provided through the tipping paper 6 at a location along the multi-component filter 4.

The multi-component filter 4 of the cigarette 10 according to the preferred embodiment of the invention shown in FIG. 1 includes four segments in abutting end-to-end relationship: a mouth end segment 12, distant from the wrapped tobacco rod 2; a first flavour release segment 14, located upstream of the mouth end segment 12; a second flavour release segment 16, located upstream of the first flavour release segment 14; and a rod end segment 18, located upstream of the second flavour release segment 16, which is adjacent to and abuts the wrapped tobacco rod 2.

The mouth end segment 12 comprises a plug of cellulose acetate tow of low filtration efficiency.

The first flavour release segment 14 comprises densely packed fine cut tobacco.

The second flavour release segment 16 comprises a plug of cellulose acetate tow of high filtration efficiency and a central cotton thread 20 loaded with liquid flavourant that extends axially through the plug of cellulose acetate tow parallel to the longitudinal axis of the cigarette 10.

The rod end segment 18 comprises a plug of cellulose acetate tow of medium to low filtration efficiency loaded with activated carbon.

During smoking of the cigarette 10, mainstream smoke is drawn downstream from the lit end of the wrapped tobacco rod through the multi-component filter 4 by the consumer. As the mainstream smoke enters the multi-component filter 4 it passes through the rod end segment 18 of the multi-component filter 4, where the medium to low filtration efficiency cellulose acetate tow partially filters out particulate phase components of the smoke and the activated carbon distributed amongst the cellulose acetate tow filters out gas phase components of the smoke. The mainstream smoke then passes downstream through the second flavour release segment 16, where the high filtration efficiency cellulose acetate tow also partially filters out particulate phase components of the smoke and flavour is released into the mainstream smoke from the flavourant loaded onto the cotton thread 20. Having passed through the second flavour release segment 16, the mainstream smoke enters the first flavour release segment 14, where further flavour is released into the smoke from the densely packed finely cut tobacco. Finally, the smoke passes through the mouth end segment 12 of the multi-component filter 4 into the consumer's mouth.

The high filtration efficiency of the cellulose acetate tow in the second flavour release segment 16, which has the highest resistance to draw of the four segments in the multi-component filter 4, maximises filtration of particulate phase components of the mainstream smoke, while the activated carbon distributed amongst the cellulose acetate tow of the rod end segment 18 maximises filtration of gas phase components of the mainstream smoke. At the same time, the first flavour release segment 14 and the second flavour release segment 16 of the multi-component filter 4 also provide dual flavour enhancement to the mainstream smoke, while the mouth end segment 12 balances the overall resistance to draw of the multi-component filter 4 and hence the cigarette 10.

The cigarette 22 according to the second embodiment of the invention shown in FIG. 2 has a multi-component filter 4 that includes five segments in abutting end-to-end relationship.

The multi-component filter 4 comprises a mouth end segment 12, a first flavour release segment 14, a second flavour release segment 16 and a rod end segment 18 of the same construction previously described above for the cigarette 10 shown in FIG. 1. In addition, the multi-component filter 4 includes a third flavour release segment 24 located upstream of the first flavour release segment 14 and downstream of the second flavour release segment 16. The third flavour release segment 24 is of similar construction to the second flavour release segment 16, but comprises a plug of cellulose acetate tow of low, rather than high, filtration efficiency and a central cotton thread 20 loaded with a second, different, liquid flavourant that extends axially through the plug of cellulose acetate tow parallel to the longitudinal axis of the cigarette 22.

In use, as mainstream smoke is drawn from the wrapped tobacco rod 2 through the multi-component filter 4, flavour is released from the second flavourant loaded onto the cotton thread 20 into the mainstream smoke as it passes through the third flavour release segment 24. The multi-component filter 4 according to the second embodiment of the invention shown in FIG. 2 thus provides triple flavour enhancement to the mainstream smoke as it is drawn through the filter 4.

The cigarette 26 according to the third embodiment of the invention shown in FIG. 3 also has a multi-component filter 4 that includes five segments in abutting end-to-end relationship.

Once again, the multi-component filter 4 comprises a mouth end segment 12, a first flavour release segment 14, a second flavour release segment 16 and a rod end segment 18 of the same construction previously described above for the cigarette 10 shown in FIG. 1. In addition, the multi-component filter 4 includes a third flavour release segment 28 located upstream of the first flavour release segment 14 and downstream of the second flavour release segment. In this embodiment the third flavour release segment is of similar construction to the first flavour release segment 14, but comprises a second, different, densely packed fine cut plant leaf, such as green tea.

In use, as mainstream smoke is drawn from the wrapped tobacco rod 2 through the multi-component filter 4, flavour is released from the second plant leaf into the mainstream smoke as it passes through the third flavour release segment 28. The multi-component filter 4 according to the third embodiment of the invention shown in FIG. 3 thus also provides triple flavour enhancement to the mainstream smoke as it is drawn through the filter 4.

To form the cigarettes 10, 22, 26 according to the first, second and third embodiments of the inventions shown in FIGS. 1, 2 and 3, respectively, the multi-component filters 4 are produced and then joined to the wrapped tobacco rods 2, which are produced in a conventional manner, by tipping paper 6 using known filter cigarette making equipment.

To produce each multi-component filter 4, separate continuous rods comprising multiple units of each segment 12, 14, 16, 18, 24, 28 of the multi-component filter 4 are produced in a known manner and then combined to form a continuous filter rod comprising multiple units of the multiple-component filter 4. The continuous filter rod is then severed at regular intervals by a cutting mechanism to yield a succession of discrete multi-component filters 4.

FIG. 4 illustrates a two-stage combining process for forming a multi-component filter 4 according to the first preferred embodiment of the invention shown in FIG. 1. As shown in FIG. 4, in the first stage of the process, two separate rods comprising multiple units of the first flavour release segment 14 and the second flavour release segment 16, each wrapped in a first web of porous plug wrap, are combined to form a stream of aligned alternating pairs of first flavour release segments 14 and second flavour release segments 16, which is then wrapped in a second web of porous plug wrap.

In the second stage, the wrapped alternating pairs of first flavour release segments 14 and second flavour release segments 16 are combined with two separate rods comprising multiple units of the rod end segment 18 and the mouth end segment 12, each wrapped in a first web of porous plug wrap, and then wrapped in a third web of porous plug wrap to produce a filter rod comprising multiple units of the multiple-component filter 4.

The separate rods comprising multiple units of the first flavour release segment 14, second flavour release segment 16, rod end segment 18 and mouth end segment 12 could alternatively be combined in one stage using a single combiner.

EXAMPLE

A filter cigarette according to the first embodiment of the invention having the dimensions and properties given in Table 1 below was produced by the two-stage combining process illustrated in FIG. 4.

	TABLE 1
	Multi-component filter	Tobacco rod
		85% American blend
		15% expanded tobacco
Encapsulated RTD (mm WG)	140
Ventilation (%)	70	—
Length (mm)	34	50
External Diameter (mm)	7.8	7.9
	Segment:
		First flavour release	Second flavour
	Mouth end segment	segment	release segment	Rod end segment	—
Length (mm)	7	10	10	7	—
Diameter (mm)	7.6	7.5	7.5	7.6	—
RTD (mm WG)	10	29	71	7	—
Cellulose acetate: denier per	8.0	—	1.5	3.0	—
filament
Cellulose acetate: total denier	28000	—	46000	35000	—
Cellulose acetate: weight (mg)	31.76	—	57.5	37.94	—
Triacetin (mg)	2.2 (7%)	—	4.0 (7%)	2.3 (6%)	—
Dry Tobacco (mg)	—	155.8	—	—	—
Oven Volatiles (mg)	—	20.3 (13%)	—	—	—
Cotton thread (mg)	—	—	1.5	—	—
Carbon (mg)	—	—	—	22.2	—
First plug wrap porosity	12000	24000	12000	12000	—
(cm3/min · cm2)
Second plug wrap porosity	24000		—
(cm3/min · cm2)
Third plug wrap porosity	24000	—
(cm3/min · cm2)
NFDPM (mg)	1
Nicotine (mg)	0.1

While the invention has been exemplified above with reference to filter cigarettes comprising multi-component filters including a rod end segment comprising a plug of cellulose acetate tow loaded with activated carbon, it will be appreciated that multi-component filters according to the present invention may be used in cigarettes and other smoking articles with or without a segment comprising a sorbent or fibrous filtration material upstream of the second flavour release segment.

It will also be appreciated that the type and quantity of plant leaf in the first flavour release segment and the type and quantity of flavourant in the second flavour release segment of multi-component filters according to the present invention may be varied in order to provide a desired rate of delivery of flavour to mainstream smoke drawn from a rod of smokable material through the filter by a consumer in use.

As described above, in use, the first flavour release segment and second flavour release segment of multi-component filters according to the present invention can each release desired flavourants into mainstream smoke passing through the multi-component filter, thereby advantageously providing dual flavour enhancement to the mainstream smoke. Through the provision of dual flavour enhancement to mainstream smoke drawn therethrough, multi-component filters according to the invention advantageously enable the manufacture of filter cigarettes and other filtered smoking articles that are flavourful, whilst still achieving significant reductions in particulate phase and gas phase components of the mainstream smoke and an acceptable overall resistance to draw.

Claims

1. A multi-component filter for a smoking article comprising: a mouth end segment;a first flavour release segment comprising plant leaf upstream of the mouth end segment; anda second flavour release segment comprising filtration material and a flavourant upstream of the first flavour release segment,wherein the resistance to draw of the second flavour release segment is greater than the resistance to draw of the first flavour release segment and the resistance to draw of the second flavour release segment is greater than the resistance to draw of mouth end segment.

2. A multi-component filter according to claim 1, wherein the first flavour release segment comprises tobacco.

3. A multi-component filter according to claim 1, wherein the second flavour release segment comprises cellulose acetate tow.

4. A multi-component filter according to claim 3, wherein the second flavour release segment comprises a plug of cellulose acetate tow impregnated with a liquid flavourant.

5. A multi-component filter according to claim 1, wherein the second flavour release segment comprises a plug of cellulose acetate including one or more threads impregnated with liquid flavourant.

6. A multi-component filter according to claim 1, further comprising: a rod end segment comprising filtration material upstream of the second flavour release segment,wherein the resistance to draw of the second flavour release segment is greater than the resistance to draw of the rod end segment.

7. A multi-component filter according to claim 6, wherein the rod end segment comprises cellulose acetate tow.

8. A multi-component filter according to claim 6, wherein the rod end segment comprises paper.

9. A multi-component filter according to claim 6, wherein the rod end segment further comprises at least one sorbent capable of removing gas phase constituents from mainstream smoke drawn through the filter.

10. A multi-component filter according to claim 9, wherein the at least one sorbent is selected from the group consisting of activated carbon, activated alumina, zeolites, molecular sieves and silica gel.

11. A multi-component filter according to claim 1, wherein the mouth end segment comprises a filtration material.

12. A multi-component filter according to claim 11, wherein the mouth end segment comprises cellulose acetate tow.

13. A smoking article comprising: a wrapped rod of smokable material; anda multi-component filter according to claim 1 attached to the rod of smokable material by tipping paper.

14. A smoking article according to claim 13, wherein the mouth end segment of the multi-component filter is a hollow tube or recess.

15. A smoking article according to claim 13, further comprising at least one circumferential row of perforations at a location along the multi-component filter.

16. A smoking article according to claim 15, wherein the at least one circumferential row of perforations is located at least 12 mm from the mouth end of the multi-component filter.