CN113439872A

CN113439872A - Filter for a smoking article

Info

Publication number: CN113439872A
Application number: CN202110799418.3A
Authority: CN
Inventors: L.穆卡洛; N.沃波尔; M.奈特; J.理查森; S.莫拉莱斯; P.温
Original assignee: British American Tobacco Investments Ltd
Current assignee: British American Tobacco Investments Ltd
Priority date: 2012-10-31
Filing date: 2013-10-29
Publication date: 2021-09-28
Also published as: US20210045436A1; JP3219297U; KR20150076216A; UA98840U; KR20200110479A; KR102219760B1; KR20210096319A; UA115998C2; HK1208601A1; GB201219540D0; US20150296878A1; CA2888967A1; UA97502U; KR20190117816A; WO2014068295A1; BR122021013385B1; CA2888967C; PH12015500947A1; JP2014090720A; KR102454343B1

Abstract

A filter for a smoking article comprising a first filter section comprising filter material and a smoke modifying additive disposed within an axial region thereof, and a second filter section connected to the first filter section and having at least one channel within an axial region thereof for directing smoke through the axial region of the first filter section in use. The smoke-modifying additive can include a flavorant, such as peppermint, and the second filter section can include a tubular section of fibrous filter material. Adsorbent filter sections can also be provided.

Description

Filter for a smoking article

This application is a divisional application of an invention patent application having an application date of 2015, 6/30, application number of 201380069516.5, and an invention name of "filter for smoking articles".

Technical Field

The present invention relates to filters for smoking articles and smoking articles comprising filters.

Background

Known smoking article filters (e.g., cigarette filters) generally comprise a continuous tow of filamentary cellulose ester. The cellulose esters are gathered together to form rods that are cut to form individual filter sections. The smoking article filter may be made from a length of filter rod or may be made from multiple lengths with or without cavities or spaces therebetween.

Disclosure of Invention

According to an embodiment of the invention, there is provided a filter for a smoking article comprising a first filter section comprising filter material and a smoke modifying additive disposed within an axial region thereof, and a second filter section connected to the first filter section, the second filter section comprising filter material and at least one channel within an axial region thereof for, in use, directing smoke through the axial region of the first filter section in which the smoke modifying additive is disposed. The first and second filter sections can be separate filter sections and/or the smoke modifying additive can be placed only within said axial region of the filter material of the first filter section or in a greater concentration within said axial region than within a non-axial region of the filter material of the first filter section.

The at least one channel can have a lower resistance to smoke passing therethrough than other regions of the filter material of the first filter section. The channel can be a hollow passage through the second filter section.

The second filter section can be connected to the first filter section so that it is just downstream or upstream of the first filter section when included into a smoking article.

The axial area of the filter material of the first and/or second filter sections may have a radius of from 1mm to 4mm and/or may be centred on the axis of the smoking article.

The first filter section can include a continuous filter material having a smoke modifying additive disposed within an axial region thereof. The second filter section can comprise a tubular filter section. The tubular filter section can be formed from a fibrous filter material.

The smoke modifying additive can be placed in a greater concentration in said axial region than in the non-axial region of the filter material of the first filter section.

The smoke modifying additive can be placed only within said axial region of the filter material of the first filter section.

The second filter section can be configured, in use, to direct a greater portion of the flue gas through the axial region of the first filter section and to direct a lesser portion of the flue gas through the non-axial region of the first filter section.

The smoke modifying additive can comprise an encapsulated additive. The smoke modifying additive can be contained within a capsule located within the first filter section and at a location within the first filter section other than the longitudinally central location.

The capsule can be located within the first filter section and at a position from 1mm to 10mm from a longitudinal central position within the first filter section.

The smoke modifying additive can be disposed on a support material. The carrier material can comprise a wire.

The filter can further comprise a third filter section connected to the first filter section such that the third filter section is located upstream of the first filter section when incorporated into a smoking article. The third filter section can be a separate filter section. The third filter section can include a fibrous filter material and a granular sorbent material. The particulate sorbent material can be disposed within a circumferential region of the third filter section, dispersed within the filter material of the third filter section, or include some particulate sorbent material disposed within a circumferential region of the third filter section and some particulate sorbent material dispersed within the third filter section.

There is also provided, in accordance with an embodiment of the present invention, a smoking article comprising a filter as defined above.

The second filter section can be disposed immediately downstream of the first filter section and at a mouth end of the smoking article.

There is further provided, in accordance with an embodiment of the present invention, a smoking article comprising a first section and a second section, the first section comprising an aerosol-generating material and an aerosol-modifying additive disposed within an axial region thereof, and the second section comprising a filter having at least one channel within an axial region thereof for directing, in use, an aerosol generated by the aerosol-generating material through the axial region of the first section.

The second section can comprise a tubular filter section. The tubular filter section can be formed from a fibrous filter material.

The aerosol-modifying additive can be placed in a greater concentration within the axial region than within the non-axial region of the aerosol-generating material of the first filter section.

The second section is capable of directing, in use, a greater portion of the flue gas through the axial region of the first section and a lesser portion of the flue gas through the non-axial region of the first section.

Drawings

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

figure 1 is a schematic illustration of a smoking article having a filter with a tubular downstream filter section and an upstream filter section comprising an encapsulated additive in the form of a breakable capsule;

FIG. 2 is a schematic view of a smoking article having a filter with a tubular filter section and a filter section comprising strands carrying an additive;

figure 3 is a schematic view of a smoking article having a filter with a tubular filter section and a filter section comprising a plurality of encapsulated additives in the form of breakable capsules;

figure 4 is a schematic view of a smoking article having a filter similar to that described with reference to figure 1 but further including another filter section having an adsorbent dispersed within the filter material;

figure 5 is a schematic view of a smoking article having a filter similar to that described with reference to figure 2 but further comprising a further filter section comprising adsorbent dispersed within the filter material and disposed within a circumferential region of the filter material;

figure 6 is a schematic view of a smoking article having an aerosol-generating section with an encapsulated additive in the form of a plurality of microcapsules dispersed within an axial region thereof and a tubular filter section; and

figure 7 is a schematic of a smoking article having a filter with a tubular upstream filter section and a downstream filter section comprising an encapsulated additive in the form of a breakable capsule.

Detailed Description

As used herein, the term "smoking article" includes smokeable products (e.g., cigarettes, cigars and cigarillos based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes) as well as heat-not-burn products and other nicotine delivery devices capable of generating aerosols for delivery to a consumer. Such smoking articles may have a filter for the flow of air drawn by the smoker.

Smoking articles such as cigarettes and their sizes are commonly named according to the length of the cigarette: "conventional" (typically in the range of 68-75 mm, e.g., from about 68 mm to about 72 mm), "short" or "miniature" (68 mm or less), "elongated" (typically in the range of 75-91mm, e.g., from about 79 mm to about 88 mm), "long" or "ultra-long" (typically in the range of 91-105 mm, e.g., from about 94 mm to about 101 mm), and "extremely long" (typically in the range of from about 110 mm to about 121 mm).

Smoking articles may also be named according to the circumference of the cigarette: "regular" (about 23-25 mm), "wide" (greater than 25 mm), "fine" (about 22-23 mm), "medium fine" (about 19-22 mm), "ultrafine" (about 16-19 mm) and "ultrafine" (less than about 16 mm). Thus, an elongated, ultra-slim cigarette, for example, would have a length of about 83 millimeters and a circumference of about 17 millimeters. Cigarettes of conventional elongated size are preferred by many consumers, i.e. having a circumference of from 23 to 25mm and an overall length of from 75 to 91 mm.

Each size can be made with filters of different lengths, with smaller filters typically being used in sizes of smaller length and circumference. Typically the filter length will be from 15mm (associated with short conventional sizes) to 30mm (associated with very long ultra-fine sizes). The tipping paper will have a length longer than the filter, for example 3 to 10mm longer than the filter.

The smoking article and filter described hereinafter can be manufactured in any of the sizes described above. The smoking article can, for example, have a length of from 70 to 100mm and a circumference of from 14 to 25 mm.

The terms 'upstream' and 'downstream' as used herein are relative terms defined with respect to the direction of mainstream smoke (or other aerosol) drawn through the smoking article in use.

Figure 1 is a schematic view of a smoking article 1 which is generally cylindrical in shape and is of conventional elongate size, i.e. having a length in the range 75-91mm and a circumference in the range 23 to 25 mm. The smoking article 1 comprises a tobacco rod 2 wrapped in a tipping material 3, in this exemplary cigarette paper the tobacco rod being longitudinally joined to a filter 4 by tipping material 5, the tipping material 5 overlapping the filter 4 and partially overlapping the tipping material 3 so as to join the filter 4 to the tobacco rod 2. The filter 4 comprises a first section 6 at the tobacco rod end of the filter 4 which comprises an adsorbent material 7 having a capsule 8 disposed therein in the axial region of the filter material of the first section 6. The axial region is in this example a region having a radius of about 3mm centred on the axis 'a' of the smoking article 1. In alternative embodiments, the radius of the axial region can be in the range from 1mm to 4mm, or from 1mm to 3mm, or about 1mm, 1.5mm, 2mm, 2.5mm, 3mm, or 3.5 mm. The capsule 8 or other additive material can be placed only within the axial region of the filter material of the first filter section 6, or can be placed with a greater concentration within the axial region than within the non-axial region of the filter material of the first filter section 6. The first section is wrapped in a first plugwrap 9.

The filter 4 further comprises a second section 10 at the mouth end of the filter 4 comprising a fibrous filter material 11, which filter material 11 is formed into a tubular shape and has a channel 12 extending through the centre of the filter material 11. The hollow or hollow passage 12 extending through the center of the filter material 11 can be from 1mm to 6mm in diameter, for example from 2mm to 5mm in diameter. The passage 12 extending through the centre of the filter material 11 is in this example an empty hollow passage. In some embodiments, the passage extends through an axial region of the filter material of the second filter section 10. The axial area of the second filter section 10 is in this example an area having a radius of about 2.5 millimetres centred on the axis 'a' of the smoking article 1. In alternative embodiments, the radius of the axial region can be in the range from 1mm to 4mm, or from 1mm to 3mm, or about 1mm, 1.5mm, 2mm, 2.5mm, 3mm, or 3.5 mm. In this example, the tubular filter section is formed from cellulose ester tow and is wrapped within a second plugwrap 13. The wall thickness of the tubular filter is about 1.5 mm. In alternative embodiments, the wall thickness can be in the range from 1mm to 4mm, or from 1mm to 3mm, or about 1mm, 1.5mm, 2mm, 2.5mm, 3mm, or 3.5 mm. However, the particular dimensions may be selected based on the density of the filter material forming the tube and the level of plasticizer applied to the material in order to obtain a tube having the desired rigidity, porosity, and other characteristics. The tubular filter section 10 can be manufactured using existing processes and machinery.

The first segment 6 is a cellulose ester segment formed by using continuous cellulose ester fibers and a plasticizer. The capsule 8 is spherical and has a diameter of 3.5 millimetres, but other shapes and sizes of capsules can be used and the capsule contains a fluid additive which alters the properties of the mainstream smoke passing through the smoking article 1. The capsule 8 can be manufactured and inserted into the first filter section 6 by using existing processes and machines. In the present example, the capsule 8 contains a mint flavor, but other fluid or particulate additives may be contained within the capsule 8. The capsule can be broken by the consumer to release the fluid additive into the sorbent filter material 11.

The axis of the smoking article 1 is shown by 'a' in figure 1, relative to which axis a the tobacco rod 2 and the first and

second filter sections

6, 10 are aligned.

In the present example, the capsule 8 is located within the 'axial region' of the first filter section 6, as defined above. The capsule 8 can be positioned such that the centre of the capsule is closer to the axis 'a' of the smoking article 1 than to the periphery of the smoking article 1. In the present example, the capsule 8 is positioned with its centre substantially along the axis 'a'. In the present example, the capsule 8 is offset from the longitudinal centre of the first filter section 6. The capsule 8 can for example be located within the first filter section 6 at a position from 1mm to 10mm from a longitudinal central position within the first filter section 6. The capsule 8 is located within a portion of the first filter section 6 closer to the downstream end of the first filter section 6. The capsule 8 is therefore closer to the second filter section 10 than to the tobacco rod 2. In particular, the distance'd' between the centre of the capsule 8 and the downstream end of the first filter section 6 is less than half the total longitudinal length of the first filter section 6. In some embodiments, the distance'd' is less than 40% of the total longitudinal length of the first filter section 6, or less than 30% of the total longitudinal length of the first filter section 6, or less than 25% of the total longitudinal length of the first filter section 6. In the present example, the distance'd' is approximately 30% of the total longitudinal length of the first filter section 6. In alternative embodiments, the capsule 8 can be positioned longitudinally centered within the first filter section 6 or closer to the upstream end than the downstream end of the first filter section 6.

In this example, the smoking article 1 has ventilation holes (not shown) through the tipping material 5 and the first plugwrap 9 to provide ventilation into the first filter section 6. If formed by in-line laser perforation, the vent holes are preferably located at a longitudinal position other than where the capsule 8 is located, in order to avoid damaging the capsule 8 during manufacturing. For example, in a smoking article having a first upstream filter section 6 of 20mm length and a second downstream filter section 10 of 7mm length, ventilation may be provided at 20mm from the mouth end, while the capsule 8 is longitudinally centred within the first filter section and extends from 15.25 mm to 18.75 mm from the mouth end as a result of having a diameter of 3.5 mm.

In use, the tobacco rod 2 of the smoking article 1 is lit by the consumer in a conventional manner and tobacco smoke is drawn from the fire coal of the tobacco rod 2 through the filter 4. The channels 12 in the second filter section 10 have a lower resistance to mainstream smoke passing through the filter 4 than the surrounding tubular filter material 11, and thus a greater proportion of mainstream smoke is directed through the channels 12. This in turn causes the mainstream smoke to flow more in the axial region around the axis 'a' of the first filter section 6, within which the capsule 8 is located. When the consumer breaks the capsule 8 before or during smoking of the smoking article 1, the smoke modifying additive (in the present case mint) contained within the capsule 8 is released in a greater concentration into the axial region of the first filter section 6 through which the increased flow of mainstream smoke is directed, due to the second filter section 10. Thus, the increased flow of mainstream smoke enhances the delivery of smoke modifying additive to the consumer, and thus the smoking article 1 is able to improve the delivery of smoke modifying additive to the consumer compared to conventional smoking articles.

Because the capsule 8 is located in the portion of the first filter section 6 that is closer to the second filter section 10 than the tobacco rod 2, the effect of the increased flow of mainstream smoke on the contents of the capsule 8 (once released) is further increased. The use of the tubular second section 10 at the mouth end of the smoking article 1 results in the capsule 8 being located closer to the mouth end of the smoking article 1 than would be possible if the first section 6 housing the capsule 8 were located at the mouth end of the smoking article 1. This is because the tube separates the first section 6 from the mouth of the consumer, preventing the contents from the capsule 8 from contacting the mouth of the consumer.

Figure 2 is a schematic view of a smoking article 21 having a filter according to a further embodiment of the invention. The features of the smoking article 21 are the same as those of the smoking article 1 described with reference to figure 1, unless otherwise specified below. The smoking article 21 comprises a tobacco rod 22 wrapped in a wrapper 23, in this example the wrapper 23 being a cigarette paper, the tobacco rod being longitudinally connected to a filter 24 by tipping material 25 overlying the filter 24 and partially overlying the wrapper 23. The filter 24 comprises a first section 26 at the end of the tobacco rod of the filter 24 which comprises an adsorbent material 27. In the present case, rather than having the capsule 8 disposed within the first filter section, the sorbent material 27 has an additive-carrying wire 28 disposed therein within an axial region (not shown) of the first section 26, wherein the axial region of the first filter section 26 is defined as described above with respect to the first filter section 6 of the smoking article 1. The strands can be formed, for example, from cotton or cellulose ester fibers and loaded with between 0.1 and 10mg of a flavorant, such as peppermint flavorant. Perfume loading levels of between 0.2 and 2mg or between 0.2 and 1mg have been found to be effective. The first section 26 is wrapped in a first plugwrap 29. The strands 28 carry an additive, in this case a mint flavor, that is capable of modifying the mainstream smoke passing through the filter 24.

The filter 24 further comprises a second section 30 at the mouth end of the filter 24 comprising a fibrous filter material 31, the filter material 31 being formed into a tubular shape and having a channel 32 extending through the centre of the filter material 11 or through an axial region thereof, similar to the second section 10 of the filter 4 of fig. 1 described above. In this example, the tubular filter section is formed from cellulose ester tow and wrapped within the second plugwrap 33.

The first segment 26 is a cellulose ester segment formed by using continuous cellulose ester fibers and a plasticizer. The wire 28 can be inserted into the filter material during formation of the filter section 26 using existing processes and machinery.

In use, the smoking article 21 shown in figure 2 operates in a similar manner to the smoking article 1 shown in figure 1. However, rather than breaking the capsule 8 to release the smoke modifying additive, the consumer can simply puff the smoking article 21 in the usual manner. When doing so, more flow of mainstream smoke is directed through the axial region of the first filter section 26 in which the strands 28 carrying smoke-modifying additive are located, due to the second filter section 30. Thus, the increased flow of mainstream smoke enhances delivery of the smoke modifying additive to the consumer when smoking the smoking article, and thus the smoking article 1 is capable of improving delivery of the smoke modifying additive to the consumer compared to conventional smoking articles.

Figure 3 is a schematic view of a smoking article 41 having a filter according to a further embodiment of the invention. Unless otherwise stated below, the features of the smoking article 41 are the same as the features of the smoking article 1 described with reference to figure 1. The smoking article 41 comprises a tobacco rod 42 wrapped in a wrapper 43, in this example a cigarette paper, the tobacco rod being longitudinally connected to the filter 44 by tipping material 45 which overlies the filter 44 and partially overlies the wrapper 43. The filter 44 includes a first section 46 at the tobacco rod end of the filter 44 that includes an adsorbent material 47. In the present case, rather than having the capsule 8 disposed within the first filter section, the sorbent material 47 has a plurality of microcapsules disposed therein within an axial region thereof, the axial region being defined as described above for the filter section 6 of the smoking article 1. The first segment 46 is wrapped in a first plugwrap 49.

The filter 44 further comprises a second section 50 at the mouth end of the filter 44 comprising a fibrous filter material 51, the filter material 51 being formed into a tubular shape and having a channel 52 extending through the centre of the filter material 11 or through an axial region thereof, similar to that described above with reference to the channel 12 of fig. 1. In this example, the tubular filter section is formed from cellulose ester tow and wrapped within a second plugwrap 53.

In use, the smoking article 41 shown in figure 3 operates in a similar manner to the smoking article 1 shown in figure 1. However, rather than destroying a single capsule 8 to release the smoke modifying additive, the consumer destroys a plurality of microcapsules 48 prior to or during smoking of the smoking article 41. When this is done, more flow of mainstream smoke is directed through the axial region of the first filter section 46 where the smoke-modifying additive released from the microcapsules is located, due to the second filter section 50. Thus, the increased flow of mainstream smoke enhances delivery of the smoke modifying additive to the consumer when smoking the smoking article, and thus the smoking article 41 can improve delivery of the smoke modifying additive to the consumer compared to conventional smoking articles.

Figure 4 is a schematic view of a smoking article 61 with a filter according to a further embodiment of the invention. The features of the smoking article 61 are the same as those of the smoking article 1 described with reference to figure 1, unless otherwise specified below. The smoking article 61 comprises a tobacco rod 62 wrapped in a wrapper 63, in this example a cigarette paper, the tobacco rod being longitudinally connected to the filter 64 by tipping material 65 which overlies the filter 64 and partially overlies the wrapper 63. The filter 64 comprises three filter sections, including a first central section 66, the first central section 66 comprising a sorbent material 67, a capsule 68 disposed within an axial region thereof, the axial region being defined as described above for the filter section 6 of the smoking article 1. The first section 66 is wrapped in a first plugwrap 69.

The second filter section 70 is disposed at the mouth end of the three-stage filter 64 and comprises a fibrous filter material 71, the filter material 71 being formed into a tubular shape and having a passage 72 extending through the centre of the filter material 11 or through an axial region thereof, similar to the passage 12 described above with reference to fig. 1. In this example, the tubular filter section is formed from cellulose ester tow and wrapped within a second plugwrap 73.

The third filter section 74 is disposed at the tobacco end of the three-stage filter 64 and comprises sorbent material particles 75, in this case activated carbon particles, dispersed within a fibrous filter material 76. In this example, the adsorbent material 75 is formed from cellulose ester tow and is wrapped within the third plugwrap 77. In the present example, 40mg of activated carbon particles are used, but other amounts may be used, for example between 10mg and 80mg or between 10mg and 50 mg.

In this example, the capsule 68 is located within a portion of the first filter section 66 that is closer to the downstream end of the first filter section 66 or closer to the second filter section 70, rather than closer to the upstream end of the first filter section or closer to the tobacco rod 62. Specifically, the distance'd' between the center of the capsule 68 and the downstream end of the first filter section 66 is approximately 30% of the total longitudinal length of the first filter section 66. In alternative embodiments, capsule 68 can be positioned longitudinally centered within first filter section 66 or closer to the upstream end than the downstream end of first filter section 66.

The first filter section 66 has a length of 10mm in this example, the second filter section 70 has a length of 7mm and the third filter section 74 has a length of 10mm, although other section lengths can be used. Ventilation is provided into the third filter section at a location 22mm from the mouth end of the smoking article 61.

In use, the smoking article 61 shown in figure 4 operates in a similar manner to the smoking article 1 shown in figure 1, and the additional third filter section 74 provides additional selective smoke filtration upstream of the first filter section 66 and therefore does not affect the delivery of smoke modifying additive to the consumer.

Figure 5 is a schematic view of a smoking article 81 having a filter according to a further embodiment of the invention. The features of the smoking article 81 are the same as the features of the smoking article 61 described with reference to figure 4, unless otherwise specified below. The smoking article 81 comprises a tobacco rod 82 wrapped in a wrapper 83, in this example the wrapper 83 is cigarette paper, the tobacco rod being longitudinally connected to the filter 84 by tipping material 85 overlying the filter 84 and partially overlying the wrapper 83. The filter 84 comprises three filter sections, including a first central section 86, which first central section 86 comprises the adsorbent material 87 and, instead of the capsule 68, comprises a wire 88 disposed therein in an axial region thereof, which axial region is defined as described above in relation to the first filter section 6 of the smoking article 1. The first section 86 is wrapped in a first plugwrap 89.

The second filter section 90 is disposed at the mouth end of the three-stage filter 84 and comprises a fibrous filter material 91, the filter material 91 being formed into a tubular shape and having a passage 92 extending through the center of the filter material 91 or through an axial region thereof, similar to the passage 12 described above with reference to fig. 1. In this example, the tubular filter section is formed from cellulose ester tow and is wrapped within a second plugwrap 93.

The third filter section 94 is disposed at the tobacco end of the three-stage filter 84 and includes sorbent material particles 95, in this case activated carbon particles, dispersed within a fibrous filter material 96. The third filter section 94 also includes sorbent material particles 97, in this case activated carbon particles, dispersed within a circumferential region thereof. However, these may be omitted in alternative examples. In this example, the fibrous filter material 96 is formed from cellulose ester tow and the third filter section 94 is wrapped within a third plugwrap 98. Particles 97 of adsorbent material interspersed within a circumferential region of the third filter section 94 are applied to the inner surface of the plugwrap 98 in a pattern of longitudinally extending strips, four of which are evenly radially spaced around the third filter section 94. Bonding the strips of granular adsorbent material 97 to the plugwrap in a symmetrical pattern around the filter section can help prevent distortion of the filter section due to the use of the adhesive and at the same time maximize the amount of granular material 97 present within the filter section.

The first filter section 86 has a length of 10mm in this example, the second filter section 90 has a length of 7mm and the third filter section 94 has a length of 10mm, although other section lengths can be used. For example, ventilation is provided into the first and third filter sections at respective positions 13mm and 20mm from the mouth end of the smoking article 81.

In use, the smoking article 81 shown in figure 5 operates in a similar manner to the smoking article 21 shown in figure 2, and the additional third filter section 94 provides additional selective smoke filtration upstream of the first filter section 86 and therefore does not affect the delivery of smoke modifying additive to the consumer.

Figure 6 is a schematic view of a smoking article 101 according to a further embodiment of the invention. The smoking article 101 is generally cylindrical in shape and is of a conventional elongate size, i.e. having a length in the range 75-91mm and a circumference in the range 23 to 25 mm. The smoking article 101 comprises a tobacco rod 102 wrapped in a leaf wrapping material 103, in this example the leaf wrapping material 103 being a cigarette paper, the tobacco rod being longitudinally connected to a filter 104 by tipping material 105 which overlies the filter 104 and partially overlies the leaf wrapping material 103. The filter 104 comprises a first section 106 at the end of the tobacco rod of the filter 104 which comprises adsorbent material 107 and is wrapped in a first plugwrap 108.

The filter 4 further comprises a second section 109 at the mouth end of the filter 104 comprising a fibrous filter material 110, the filter material 110 being formed into a tubular shape and having a channel 111 extending through the centre of the filter material 110 or through an axial region thereof, similar to the channel 12 described above with reference to fig. 1. In this example, the tubular filter section is formed from cellulose ester tow and wrapped within a second plugwrap 112.

The tobacco rod 102 comprises a plurality of microcapsules 113 disposed within an axial region of the tobacco rod 102 at the filter end thereof, the axial region being similar in position and size to that defined above in relation to the first filter section 6 of the smoking article 1, except that it is located within the tobacco rod 102.

The axis of the smoking article 1 along which the tobacco rod 2 and the first and

second filter sections

46, 50 are arranged is shown in figure 1 by 'a'.

In use, the smoking article 101 shown in figure 6 operates in a similar manner to the smoking article 41 shown in figure 3. However, rather than destroying the plurality of microcapsules 48 within the filter section prior to or during smoking of the smoking article 41, the consumer destroys the plurality of microcapsules 113 located within the tobacco rod 102. When this is done, the increased flow of mainstream smoke is directed through the axial region of the filter end of the tobacco rod 2 where the smoke-modifying additive released from the microcapsules is located, due to the second filter section 109. The increased flow of mainstream smoke enhances delivery of smoke modifying additives to the consumer, and thus the smoking article 101 can improve delivery of smoke modifying additives to the consumer compared to conventional smoking articles.

Figure 7 is a schematic view of a smoking article 121 with a filter according to a further embodiment of the invention. Unless otherwise stated below, the features of the smoking article 121 are the same as the features of the smoking article 1 described with reference to figure 1. The smoking article 121 comprises a tobacco rod 122 wrapped in a leaf wrapping material 123, in this example the leaf wrapping material 123 being a cigarette paper, the tobacco rod being longitudinally connected to a filter 124 by tipping material 125 overlying the filter 124 and partially overlying the leaf wrapping material 123. The filter 124 comprises a first section 126 at the mouth end of the filter 124, rather than at the tobacco end of the filter, which comprises a sorbent material 127 and a capsule 128 disposed within an axial region thereof, which axial region is defined as described above in relation to the first filter section 6 of the smoking article 1. The first section 126 is wrapped in a first plugwrap 129. The capsule 128 contains an additive, in this case a mint flavor, that modifies the mainstream smoke passing through the filter 124.

The filter 124 further comprises a second section 130 at the tobacco rod end of the filter 124 rather than at the mouth end of the filter 124, which comprises a fibrous filter material 131, the filter material 131 being formed into a tubular shape and having a channel 132 extending through the centre of the filter material 131 or through an axial region thereof, similar to the second section 10 of the filter 4 described above with reference to fig. 1. In this example, the tubular filter section is formed from cellulose ester tow and wrapped within a second plugwrap 133.

The first segment 126 is a cellulose ester segment formed by using continuous cellulose ester fibers and a plasticizer. The capsule 128 can be inserted into the filter material during formation of the filter section 126 using existing processes and machinery. In this example, the capsule 128 is located within a portion of the first filter section 126 that is closer to the upstream end of the first filter section 126 or closer to the second filter section 130 than to the downstream end of the first filter section 126 or closer to the mouth end of the smoking article 121. Specifically, the distance'd' between the center of the capsule 128 and the upstream end of the first filter section 126 is approximately 30% of the total longitudinal length of the first filter section 126. In alternative embodiments, the capsule 128 can be positioned longitudinally centered within the first filter section 126 or closer to the downstream end than the upstream end of the first filter section 126.

Although not shown, the embodiment of fig. 7 may also include a third filter section upstream of the second filter section 130, corresponding to either of the

third filter sections

74, 94 described with reference to fig. 4 and 5.

In use, the smoking article 121 shown in figure 7 operates in a similar manner to the smoking article 1 shown in figure 1. When the capsule 128 ruptures thereby releasing the smoke modifying additive, the increased flow of mainstream smoke is directed through the axial region of the first filter section 126 to which the contents of the capsule 128 have been released, due to the second filter section 130. Thus, the increased flow of mainstream smoke enhances delivery of the smoke modifying additive to the consumer when smoking the smoking article, and thus the smoking article 121 can improve delivery of the smoke modifying additive to the consumer compared to conventional smoking articles.

Specific embodiments of the present invention have been described, but the present invention is not limited to these embodiments. For example, although the second filter section has been described above as a tubular portion of fibrous filter material, it may take other forms, such as a section of filter material having a region of lower density extending through an axial region thereof. Also, tubular or other sections having a reduced density in the axial region have been described above at the mouth end of the filter in some embodiments, but could alternatively be used as the central or upstream end of a multi-piece filter in any embodiment, such as upstream of the section where the smoke modifying additive is located, while still benefiting from the effects of the present invention. In particular, the presence of such a filter section can facilitate the mainstream smoke to be directed to an axial region of the smoking article (both upstream and downstream of the axial region) due to the lower resistance to draw consistent with the axial region.

The first, second and (when present) third filter sections described above are separation segments. Although the first, second and (when present) third filter sections described above are joined together using tipping material, they are separated and spaced apart from each other after they are formed and before they are joined together. Tipping material also connects the filter section to the respective tobacco rod of each embodiment. In an alternative example of each of the above embodiments, another plugwrap can be used to join the first, second and (when present) third discrete filter segments before they are joined to the tobacco rod by the use of tipping material.

To address the various problems and advance the art, the overall disclosure shows, by way of example, various embodiments in which the claimed invention may be practiced and provides superior delivery of smoke modifying additives. The advantages and features of the present disclosure are merely representative of the embodiments and are not exhaustive and/or exclusive. They are presented only to facilitate an understanding and teaching of the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the present disclosure are not to be considered limited to the disclosure defined by the claims or the equivalents of the claims, and that other embodiments may be employed and modifications may be made without departing from the scope and/or spirit of the present disclosure. Various embodiments may suitably comprise, consist essentially of, or consist of various combinations of the disclosed elements, components, features, portions, steps, devices, etc. Moreover, this disclosure includes other inventions not presently claimed, but which may be claimed in the future.

Claims

1. A filter for a smoking article comprising:

a first separate filter section comprising a filter material and an aerosol-modifying additive disposed in an axial region thereof; and

a second separate filter section connected to the first filter section, the second filter section comprising filter material and at least one channel in an axial region of the filter material, the second filter section for, in use, directing aerosol through the axial region of the first filter section in which the aerosol-modifying additive is disposed, wherein the aerosol-modifying additive is disposed only in the axial region of the filter material of the first filter section, or is disposed in a greater concentration in the axial region than in a non-axial region of the filter material of the first filter section, and wherein the second filter section is configured to, in use, pass through a non-axial region of the first filter section, directing a greater portion of aerosol through the axial region of the first filter section; and

wherein the second filter section is connected to the first filter section such that the second filter section is upstream of the first filter section when incorporated into a smoking article.

2. The filter according to claim 1, wherein the at least one channel has less resistance to aerosol passing therethrough than other regions of the filter material of the first filter section.

3. The filter of claim 1 or 2, wherein the passage is a hollow passage through the second filter section.

4. A filter according to any preceding claim, wherein the axial area of the filter material of the first and/or second filter sections has a radius from 1mm to 4mm and is centred on the axis of the smoking article.

5. A filter according to any preceding claim, wherein the first filter section comprises a continuous filter material having an aerosol-modifying additive disposed in an axial region thereof.

6. A filter as claimed in any preceding claim, wherein the second filter section comprises a tubular filter section.

7. The filter of claim 6, wherein the tubular filter section is formed of a fibrous filter material.

8. A filter according to any preceding claim, wherein the aerosol-modifying additive comprises an encapsulated additive.

9. The filter of claim 8, wherein the aerosol-modifying additive is contained within a capsule located within the first filter section at a location within the first filter section other than a longitudinally central location.

10. The filter of claim 9, wherein the capsule is located within the first filter section at a location from 1mm to 10mm from a longitudinally central location within the first filter section.

11. A filter according to any one of claims 1 to 7, wherein the aerosol-modifying additive is disposed on a carrier material.

12. The filter of claim 11, wherein the carrier material comprises wires.

13. A filter according to any preceding claim, further comprising a third separate filter section connected to the first filter section such that when incorporated into a smoking article the third separate filter section is located just upstream of the first filter section.

14. The filter of claim 13, wherein the third filter section comprises a fibrous filter material and a granular sorbent material.

15. The filter of claim 14, wherein the particulate sorbent material is disposed in a circumferential region of the third filter section, interspersed within the filter material of the third filter section, or comprises some particulate sorbent material disposed in a circumferential region of the third filter section and some particulate sorbent material interspersed within the third filter section.

16. A smoking article comprising a filter according to any one of the preceding claims.