WO 2014/068295 PCT/GB2013/052813 A Filter for a Smoking Article Technical Field The invention relates to a filter for a smoking article and to a smoking article including 5 a filter. Background Known smoking article filters, such as cigarette filters, generally comprise a continuous tow of filamentary cellulose acetate. The cellulose acetate is gathered together to form a 20 rod which is cut to form individual filter sections. The smoking article filter may be made of one segment of filter rod, or may be made from multiple segments, with or without a cavity or spaces between them. Summary 15 According to embodiments 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 in an axial region thereof and a second filter section connected to said first filter section, the second filter section comprising filter material and at least one channel located in an axial region thereof for directing smoke, in use, through the axial 20 region of the first filter section in which the smoke modifying additive is disposed. The first and second filter sections can be discrete filter sections and/or the smoke modifying additive can be disposed only in said axial region of the filter material of the first filter section or in a greater concentration in said axial region than in non-axial regions of the filter material of the first filter section. 25 The at least one channel can have a lower resistance to smoke passing through it than other regions of the filter material of the first filter section. The channel can be a hollow passageway through the second filter section. 30 The second filter section can be connected to said first filter section so as to make the second filter section immediately either downstream or upstream of said first filter section when incorporated into a smoking article. The axial region of said filter material of said first and/or second filter sections can 35 have a radius of from 1mm to 4mm and/or can be centred on the axis of the smoking article.
WO 2014/068295 PCT/GB2013/052813 -2 The first filter section can comprise continuous filter material having the smoke modifying additive disposed in the axial region thereof. The second filter section can comprise a tubular filter section. The tubular filter section can be formed from a 5 fibrous filter material. The smoke modifying additive can be disposed in a greater concentration in said axial region than in non-axial regions of the filter material of the first filter section. 2o The smoke modifying additive can be disposed only in 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 smoke through the axial region of the first filter section than through non-axial regions of the 15 first filter section. The smoke modifying additive can comprise an encapsulated additive. The smoke modifying additive can be contained within a capsule which is located within the first filter section at a position other than a longitudinally central position within the first 20 filter section. The capsule can be located within the first filter section at a position from 1mm to iomm from a longitudinally central position within the first filter section. 25 The smoke modifying additive can be disposed on a carrier material. The carrier material can comprise a thread. The filter can further comprise a third filter section connected to said first filter section so as to make it upstream of said first filter section when incorporated into a smoking 30 article. The third filter section can be a discrete filter section. The third filter section can comprise fibrous filter material and a granular adsorbent material. The granular adsorbent material can be disposed in a circumferential region of the third filter section, dispersed within the filter material of the third filter section, or comprises some granular adsorbent material disposed in a circumferential region of the third 35 filter section and some granular adsorbent material dispersed within the third filter section.
WO 2014/068295 PCT/GB2013/052813 -3 According to embodiments of the invention, there is also provided a smoking article comprising a filter as defined above. 5 The second filter section can be arranged immediately downstream of said first filter section and at the mouth-end of the smoking article. According to embodiments of the invention, there is further provided a smoking article comprising a first section comprising an aerosol generating material and an aerosol 10 modifying additive disposed in an axial region thereof, and a second section comprising a filter having at least one channel located in an axial region thereof for directing the aerosol generated by the aerosol generating material, in use, through the axial region of the first section. 25 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 disposed in a greater concentration in said axial region than in non-axial regions of the aerosol generating material of the first section. 20 The second section, in use, can direct a greater portion of smoke through the axial region of the first section than through non-axial regions of the first section. Brief Description of the Drawings 25 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 including an encapsulated additive in the form of a frangible capsule; 30 Figure 2 is a schematic illustration of a smoking article having a filter with a tubular filter section and a filter section including a thread carrying an additive; Figure 3 is a schematic illustration of a smoking article having a filter with a tubular filter section and a filter section including an encapsulated additive in the form of a plurality of frangible capsules; WO 2014/068295 PCT/GB2013/052813 -4 Figure 4 is a schematic illustration of a smoking article having a filter similar to that described with reference to Figure 1 but also including a further filter section having an adsorbent dispersed in filter material; Figure 5 is a schematic illustration of a smoking article having a filter similar to that 5 described with reference to Figure 2 but also comprising a further filter section comprising an adsorbent dispersed in filter material and disposed in a circumferential region of the filter material; Figure 6 is a schematic illustration of a smoking article with an aerosol generating section and a tubular filter section, the aerosol generating section having an 1o encapsulated additive in the form of a plurality of microcapsules dispersed within an axial region thereof; and Figure 7 is a schematic illustration of a smoking article having a filter with a tubular upstream filter section and a downstream filter section including an encapsulated additive in the form of a frangible capsule. 15 Detailed Description As used herein, the term "smoking article" includes smokeable products such as cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat-not-burn 20 products and other nicotine delivery devices capable of generating an aerosol for delivery to a consumer. Such smoking articles may be provided with a filter for the gaseous flow drawn by the smoker. Smoking articles such as cigarettes and their formats are often named according to the 25 cigarette length: "regular" (typically in the range 68 -75 mm, e.g. from about 68 mm to about 72 mm), "short" or "mini" (68 mm or less), "king-size" (typically in the range 75 9imm, e.g. from about 79 mm to about 88 mm), "long" or "super-king" (typically in the range 91-105 mm, e.g. from about 94 mm to about 101 mm) and "ultra-long" (typically in the range from about no mm to about 121 mm). 30 They are also named according to the cigarette circumference: "regular" (about 23-25 mm), "wide" (greater than 25 mm), "slim" (about 22-23 mm), "demi-slim" (about 19-22 mm), "super-slim" (about 16-19 mm), and "micro-slim" (less than about 16 mm). Accordingly, a cigarette in a king-size, super-slim format will, for example, have a 35 length of about 83 mm and a circumference of about 17 mm. Cigarettes in the regular, WO 2014/068295 PCT/GB2013/052813 -5 king-size format are preferred by many customers, namely with a circumference of from 23 to 25 mm and an overall length of from 75 to 91 mm. Each format may be produced with filters of different lengths, smaller filters being 5 generally used in formats of smaller lengths and circumferences. Typically the filter length will be from 15mm, associated with short, regular formats, to 3omm, associated with ultra-long super-slim formats. The tipping paper will have a greater length than the filter, for example from 3 to 10mm longer. 20 Smoking articles and filters described hereinafter can be manufactured in any of the above formats. The smoking article can, for instance, be from 70 to 100mm in length and from 14 to 25mm in circumference. The terms 'upstream' and 'downstream' used herein are relative terms defined in 15 relation to the direction of mainstream smoke (or other aerosol) drawn though a smoking article in use. Figure 1 is a schematic illustration of a smoking article 1 which is generally cylindrical in shape and is in the regular, king size format, namely having a length in the range 75 20 9imm and a circumference in the range 23 to 25mm. The smoking article 1 includes a tobacco rod 2 wrapped in a wrapping material 3, in this example cigarette paper, connected longitudinally to a filter 4 by tipping material 5 overlaying the filter 4 and partially overlaying the wrapping material 3 so as to connect 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 25 comprising absorbent material 7 having a capsule 8 disposed therein in an axial region of the filter material of the first section 6. The axial region is a region, in the present example, centred on the axis 'a' of the smoking article 1, having a radius of about 3mm. In alternative embodiments, the radius of the axial region can be anywhere from 1mm to 4mm, or from 1mm to 3mm, or about imm, 1.5mm, 2mm, 2.5mm, 3mm or 3.5mm. 30 The capsule 8, or other additive material, can be disposed only in the axial region of the filter material of the first filter section 6, or can be disposed in greater concentration in the axial region than in non-axial regions of the filter material of the first filter section 6. The first section is wrapped in a first plug wrap 9. 35 The filter 4 further comprises a second section 10 at the mouth-end of the filter 4 comprising fibrous filter material 11 formed into a tubular shape and having a channel WO 2014/068295 PCT/GB2013/052813 -6 12 extending through the centre of the filter material 11. The empty or hollow channel 12 extending through the centre of the filter material 11 can be from 1mm to 6mm in diameter, for instance from 2mm to 5mm in diameter. The channel 12 extending through the centre of the filter material 11 is, in the present example, an empty, hollow 5 passageway. The channel, in some embodiments, extends through an axial region of the filter material of the second filter section 10. The axial region of the second filter section 10 is a region, in the present example, centred on the axis 'a' of the smoking article 1, having a radius of about 2.5mm. In alternative embodiments, the radius of the axial region can be anywhere from 1mm to 4mm, or from 1mm to 3mm, or about 1mm, 10 1.5mm, 2mm, 2.5mm, 3mm or 3-5mm. In the present example, the tubular filter section is formed from cellulose acetate tow and is wrapped in a second plug wrap 13. The wall thickness of the tubular filter is about 1.5mm. In alternative embodiments, the wall thickness can be anywhere from 1mm to 4mm, or from 1mm to 3mm, or about 1mm, 1.5mm, 2mm, 2.5mm, 3mm or 3-5mm. However, the specific dimensions may be 25 selected based on the density of filter material forming the tube and the level of plasticiser applied to the material, to result in a tube having the desired rigidity, porosity or other characteristics. The tubular filter section 10 can be manufactured using existing processes and machinery. 20 The first segment 6 is a cellulose acetate segment formed using continuous cellulose acetate fibres and a plasticiser. The capsule 8 is spherical and has a diameter of 3-5mm, although other shapes and sizes of capsule can be used, and contains a fluid additive which modifies properties of mainstream smoke passing through the smoking article 1. The capsule 8 can be manufactured and inserted into the first filter section 6 using 25 existing processes and machinery. In the present example, the capsule 8 contains menthol flavourant, although other fluids or granular additives could be contained within the capsule 8. The capsule can be ruptured by a consumer to release the fluid additive into the absorbent filter material 11. 30 The axis of the smoking article 1, about which the tobacco rod 2 and first and second filter sections 6, 10 are aligned, is indicated as 'a' in Figure 1. In the present example, the capsule 8 is located in an 'axial region' of the first filter section 6, as defined above. The capsule 8 can be located such that the centre of the 35 capsule is closer to the axis 'a' of the smoking article 1 than to the outer periphery of the smoking article 1. In the present example, the capsule 8 is located with its centre WO 2014/068295 PCT/GB2013/052813 -7 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 instance, be located within the first filter section 6 at a position from 1mm to 10mm from a longitudinally central position within the first filter section 6. The capsule 8 is located 5 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 of the total longitudinal length of the first filter section 6. In some embodiments, the distance 'd' is lo less than 40%, less than 30% 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 located longitudinally centrally within the first filter section 6 or closer to the upstream end of the first filter section 6 than to the downstream end. 15 The smoking article 1 is, in the present example, provided with ventilation holes (not shown) through the tipping material 5 and first plug wrap 9, providing ventilation into the first filter section 6. If formed by online laser perforation, the ventilation holes are preferably located in a longitudinal position other than that in which the capsule 8 is 20 located, to avoid damaging the capsule 8 during manufacture. For instance, in a smoking article with a first upstream filter section 6 of length 20mm and a second downstream filter section 10 of length 7mm, ventilation may be provided at 20mm from the mouth end, while the capsule 8 is longitudinally centrally located within the first filter section and, at 3.5mm diameter, therefore extends from 15.25mm to 25 18.75mm from the mouth end. In use, the tobacco rod 2 of the smoking article 1 is lit by a consumer in the conventional manner and tobacco smoke is drawn from burning coal of the tobacco rod 2 through the filter 4. The channel 12 in the second filter section 10 has a lower 30 resistance to mainstream smoke passing through the filter 4 than the surrounding tubular filter material 11, and therefore a greater proportion of mainstream smoke is directed through the channel 12. This, in turn, results in a greater flow of mainstream smoke in the axial region around the axis 'a' of the first filter section 6, in which the capsule 8 is located. When the consumer breaks the capsule 8 either prior to or in the 35 course of smoking the smoking article 1, the smoke modifying additive contained therein, in the present case menthol, is released in greater concentration into the axial WO 2014/068295 PCT/GB2013/052813 -8 region of the first filter section 6 through which an increased flow of mainstream smoke is directed, as a result of the second filter section 10. Accordingly, the increased flow of mainstream smoke enhances the delivery of the smoke modifying additive to the consumer and the smoking article 1 can therefore exhibit improved delivery of a smoke 5 modifying additive to a consumer compared to conventional smoking articles. Since the capsule 8 is located within a portion of the first filter section 6 closer to the second filter section 10 than to the tobacco rod 2, the effect of the increased flow of mainstream smoke on the contents of the capsule 8, once released, is further enhanced. 2o The use of the tubular second section 10 at the mouth end of the smoking article 1 enables the capsule 8 to be located closer to the mouth-end of the smoking article 1 than would be possible if the first section 6 containing the capsule 8 were at the mouth end of the smoking article 1. This is because the tube separates the first section 6 from the consumer's mouth, preventing the content from the capsule 8 from contacting the 15 consumer's mouth. Figure 2 is a schematic illustration 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 20 otherwise stated below. The smoking article 21 includes a tobacco rod 22 wrapped in a wrapping material 23, in this example cigarette paper, connected longitudinally to a filter 24 by tipping material 25 overlaying the filter 24 and partially overlaying the wrapping material 23. The filter 24 comprises a first section 26 at the tobacco rod end of the filter 24 comprising absorbent material 27. In the present case, rather than 25 having a capsule 8 disposed in the first filter section, the absorbent material 27 has an additive carrying thread 28 disposed therein in an axial region (not shown) of the first section 26, wherein the axial region of the first filter section 26 is as defined in relation to the first filter section 6 of the smoking article 1 described above. The thread can, for instance, be formed from cotton or cellulose acetate fibres and be loaded with between 30 0.1 and 1omg of flavourant, such as menthol flavourant. Loading levels of between 0.2 to 2mg, or between 0.2 and 1mg of flavourant have been found to be effective. The first section 26 is wrapped in a first plug wrap 29. The thread 28 carries an additive capable of modifying mainstream smoke passing through the filter 24, in the present case menthol flavourant. 35 WO 2014/068295 PCT/GB2013/052813 -9 The filter 24 further comprises a second section 30 at the mouth-end of the filter 24 comprising fibrous filter material 31 formed into a tubular shape and having a channel 32 extending through the centre of the filter material 31, or through an axial region thereof, similar to the second section 10 of the filter 4 of Figure 1 described above. In 5 the present example, the tubular filter section is formed from cellulose acetate tow and is wrapped in a second plug wrap 33. The first segment 26 is a cellulose acetate segment formed using continuous cellulose acetate fibres and a plasticiser. The thread 28 can be inserted into the filter material 20 during formation of the filter section 26 using existing processes and machinery. In use, the smoking article 21 illustrated in Figure 2 operates in a similar way to the smoking article 1 illustrated in Figure 1. However, rather than breaking a capsule 8 to release a smoke modifying additive, the consumer can simply smoke the smoking 15 article 21 in the usual manner. When doing so, a greater flow of mainstream smoke is directed, as a result of the second filter section 30, through the axial region of the first filter section 26 in which the thread 28 carrying the smoke modifying additive is located. Accordingly, when the smoking article is smoked, the increased flow of mainstream smoke enhances the delivery of the smoke modifying additive to the 20 consumer and the smoking article 1 can therefore exhibit improved delivery of a smoke modifying additive to a consumer than convention smoking articles. Figure 3 is a schematic illustration of a smoking article 41 having a filter according to a further embodiment of the invention. The features of the smoking article 41 are the 25 same as those of the smoking article 1 described with reference to Figure 1, unless otherwise stated below. The smoking article 41 includes a tobacco rod 42 wrapped in a wrapping material 43, in this example cigarette paper, connected longitudinally to a filter 44 by tipping material 45 overlaying the filter 44 and partially overlaying the wrapping material 43. The filter 44 comprises a first section 46 at the tobacco rod end 30 of the filter 44 comprising absorbent material 47. In the present case, rather than having a capsule 8 disposed in the first filter section, the absorbent material 47 has a plurality of microcapsules disposed therein in an axial region thereof, the axial region being as defined in relation to the first filter section 6 of the smoking article 1 described above. The first section 46 is wrapped in a first plug wrap 49. 35 WO 2014/068295 PCT/GB2013/052813 - 10 The filter 44 further comprises a second section 50 at the mouth-end of the filter 44 comprising fibrous filter material 51 formed into a tubular shape and having a channel 52 extending through the centre of the filter material 51 or through the axial region thereof, as described above with reference to the channel 12 of Figure 1. In the present 5 example, the tubular filter section is formed from cellulose acetate tow and is wrapped in a second plug wrap 53. In use, the smoking article 41 illustrated in Figure 3 operates in a similar way to the smoking article 1 illustrated in Figure 1. However, rather than breaking a single capsule 10 8 to release a smoke modifying additive, the consumer breaks the plurality of microcapsules 48 prior to or in the course of smoking the smoking article 41. When doing so, a greater flow of mainstream smoke is directed, as a result of the second filter section 50, through the axial region of the first filter section 46 in which the smoke modifying additive released from the microcapsules is located. Accordingly, when the 15 smoking article is smoked, the increased flow of mainstream smoke enhances the delivery of the smoke modifying additive to the consumer and the smoking article 41 can therefore exhibit improved delivery of a smoke modifying additive to a consumer than convention smoking articles. 20 Figure 4 is a schematic illustration of a smoking article 61 having 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 stated below. The smoking article 61 includes a tobacco rod 62 wrapped in a wrapping material 63, in this example cigarette paper, connected longitudinally to a 25 filter 64 by tipping material 65 overlaying the filter 64 and partially overlaying the wrapping material 63. The filter 64 comprises three filter sections, including a first central section 66 comprising absorbent material 67 and a capsule 68 disposed in an axial region thereof, the axial region being as defined in relation to the first filter section 6 of the smoking article 1 described above. The first section 66 is wrapped in a 30 first plug wrap 69. A second filter section 70 is disposed at the mouth-end of the three-part filter 64 and comprises fibrous filter material 71 formed into a tubular shape and having a channel 72 extending through the centre of the filter material 71 or through the axial region 35 thereof, as described above with reference to the channel 12 of Figure 1. In the present WO 2014/068295 PCT/GB2013/052813 - 11 example, the tubular filter section is formed from cellulose acetate tow and is wrapped in a second plug wrap 73. A third filter section 74 is disposed at the tobacco-end of the three-part filter 64 and 5 comprises granules of adsorbent material 75, in the present case activated carbon granules, dispersed within a fibrous filter material 76. In the present example, the adsorbent material 75 is formed from cellulose acetate tow and is wrapped in a third plug wrap 77. In the present example, 40mg of activated carbon granules are used, although other amounts, such as between iomg and 80mg or between iomg and 50mg 20 can be used. In the present example, the capsule 68 is located within a portion of the first filter section 66 closer to the downstream end of the first filter section 66, or to the second filter section 70, than to the upstream end of the first filter section, or to the tobacco 15 rod 62. In particular, the distance 'd' between the centre 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, the capsule 68 can be located longitudinally centrally within the first filter section 66 or closer to the upstream end of the first filter section 66 than to the downstream end. 20 The first filter section 66 has a length of iomm in the present example, the second filter section 70 a length of 7mm and the third filter section 74 a length of 10mm, although other section lengths can be used. Ventilation is provided into the third filter section at a position 22mm from the mouth end of the smoking article 61. 25 In use, the smoking article 61 illustrated in Figure 4 operates in a similar way to the smoking article 1 illustrated in Figure 1, with the additional third filter section 74 providing additional selective smoke filtration upstream of the first filter section 66 and therefore without influencing the delivery of smoke modifying additive to the 30 consumer. Figure 5 is a schematic illustration 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 those of the smoking article 61 described with reference to Figure 4, unless 35 otherwise stated below. The smoking article 81 includes a tobacco rod 82 wrapped in a wrapping material 83, in this example cigarette paper, connected longitudinally to a WO 2014/068295 PCT/GB2013/052813 - 12 filter 84 by tipping material 85 overlaying the filter 84 and partially overlaying the wrapping material 83. The filter 84 comprises three filter sections, including a first central section 86 comprising absorbent material 87 and, rather than a capsule 68, a thread 88 disposed therein, in an axial region thereof, the axial region being as defined 5 in relation to the first filter section 6 of the smoking article 1 described above. The first section 86 is wrapped in a first plug wrap 89. A second filter section 90 is disposed at the mouth-end of the three-part filter 84 and comprises fibrous filter material 91 formed into a tubular shape and having a channel 10 92 extending through the centre of the filter material 91 or through the axial region thereof, as described above with reference to the channel 12 of Figure 1. In the present example, the tubular filter section is formed from cellulose acetate tow and is wrapped in a second plug wrap 93. 15 A third filter section 94 is disposed at the tobacco-end of the three-part filter 84 and comprises granules of adsorbent material 95, in the present case activated carbon granules, dispersed within a fibrous filter material 96. The third filter section 94 also comprises granules of adsorbent material 97, in the present case activated carbon granules, dispersed in a circumferential region thereof. However, in alternative 20 examples these may be omitted. In the present example, the fibrous filter material 96 is formed from cellulose acetate tow and the third filter section 94 is wrapped in a third plug wrap 98. The granules of adsorbent material 97 dispersed in a circumferential region of the third filter section 94 are applied to an inner surface of the plug wrap 98 in a pattern of longitudinally extending strips, four of which are evenly radially spaced 25 around the third filter section 94. Adhering strips of granular adsorbent material 97 to plug wrap in a symmetrical pattern about a filter section can help to prevent the filter section becoming misshapen as a result of the adhesive used, while maximising the amount of granular material 97 present in the filter section. 30 The first filter section 86 has a length of 1omm in the present example, the second filter section 90 a length of 7mm and the third filter section 94 a length of 1omm, although other section lengths can be used. Ventilation is, for instance, provided into the first and third filter sections at respective positions of 13mm and 20mm from the mouth end of the smoking article 81. 35 In use, the smoking article 81 illustrated in Figure 5 operates in a similar way to the WO 2014/068295 PCT/GB2013/052813 - 13 smoking article 21 illustrated in Figure 2, with the additional third filter section 94 providing additional selective smoke filtration upstream of the first filter section 86 and therefore without influencing the delivery of smoke modifying additive to the consumer. 5 Figure 6 is a schematic illustration of a smoking article 101 according to a further embodiment of the invention. The smoking article 101 is generally cylindrical in shape and is in the regular, king size format, namely having a length in the range 75 - 91mm and a circumference in the range 23 to 25mm. The smoking article 101 includes a 20 tobacco rod 102 wrapped in a wrapping material 103, in this example cigarette paper, connected longitudinally to a filter 104 by tipping material 105 overlaying the filter 104 and partially overlaying the wrapping material 103. The filter 104 comprises a first section 106 at the tobacco rod end of the filter 104 comprising absorbent material 107 and wrapped in a first plug wrap 108. 15 The filter 4 further comprises a second section 109 at the mouth-end of the filter 104 comprising fibrous filter material 11o formed into a tubular shape and having a channel 11 extending through the centre of the filter material 11o or through the axial region thereof, as described above with reference to the channel 12 of Figure 1. In the present 20 example, the tubular filter section is formed from cellulose acetate tow and is wrapped in a second plug wrap 112. The tobacco rod 102 includes a plurality of microcapsules 113 disposed in an axial region thereof at the filter end of the tobacco rod 102, the axial region being similar in 25 location and size to that defined in relation to the first filter section 6 of the smoking article 1 described above, except that it is located within the tobacco rod 102. The axis of the smoking article 1, along which the tobacco rod 2 and first and second filter sections 46, 50 are disposed, is indicated as 'a' in Figure 1. 30 In use, the smoking article 101 illustrated in Figure 6 operates in a similar way to the smoking article 41 illustrated in Figure 3. However, rather than breaking the plurality of microcapsules 48 in a filter section prior to or in the course of smoking the smoking article 41, the consumer breaks the plurality of microcapsules 113 located in the tobacco 35 rod 102. When doing so, a greater flow of mainstream smoke is directed, as a result of the second filter section 109, through the axial region of the filter end of the tobacco rod WO 2014/068295 PCT/GB2013/052813 - 14 2 in which the smoke modifying additive released from the microcapsules is located. The increased flow of mainstream smoke enhances the delivery of the smoke modifying additive to the consumer and the smoking article 101 can therefore exhibit improved delivery of a smoke modifying additive to a consumer than convention smoking articles. 5 Figure 7 is a schematic illustration of a smoking article 121 having a filter according to a further embodiment of the invention. The features of the smoking article 121 are the same as those of the smoking article 1 described with reference to Figure 1, unless otherwise stated below. The smoking article 121 includes a tobacco rod 122 wrapped in lo a wrapping material 123, in this example cigarette paper, connected longitudinally to a filter 124 by tipping material 125 overlaying the filter 124 and partially overlaying the 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, comprising absorbent material 127 and a capsule 128 disposed in an axial region thereof, the axial region being as 25 defined in relation to the first filter section 6 of the smoking article 1 described above. The first section 126 is wrapped in a first plug wrap 129. The capsule 128 contains an additive capable of modifying mainstream smoke passing through the filter 124, in the present case menthol flavourant. 20 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 comprising fibrous filter material 131 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 of Figure 1. In the present example, the tubular filter section is formed 25 from cellulose acetate tow and is wrapped in a second plug wrap 133. The first segment 126 is a cellulose acetate segment formed using continuous cellulose acetate fibres and a plasticiser. The capsule 128 can be inserted into the filter material during formation of the filter section 126 using existing processes and machinery. In 30 the present example, the capsule 128 is located within a portion of the first filter section 126 closer to the upstream end of the first filter section 126, or to the second filter section 130, than to the downstream end of the first filter section 126, or to the mouth end of the smoking article 121. In particular, the distance 'd' between the centre of the capsule 128 and the upstream end of the first filter section 126 is approximately 30% of 35 the total longitudinal length of the first filter section 126. In alternative embodiments, the capsule 128 can be located longitudinally centrally within the first filter section 126 WO 2014/068295 PCT/GB2013/052813 - 15 or closer to the downstream end of the first filter section 126 than to the upstream end. Although not illustrated, the embodiment of Figure 7 may also comprise a third filter section upstream of the second filter section 130 corresponding to either of the third 5 filter sections 74, 94 described with reference to Figures 4 and 5. In use, the smoking article 121 illustrated in Figure 7 operates in a similar way to the smoking article 1 illustrated in Figure 1. When the capsule 128 is ruptured to release a smoke modifying additive, a greater flow of mainstream smoke is directed, as a result of 1o the second filter section 130, through the axial region of the first filter section 126 in which the contents of the capsule 128 have been released. Accordingly, when the smoking article is smoked, the increased flow of mainstream smoke enhances the delivery of the smoke modifying additive to the consumer and the smoking article 121 can therefore exhibit improved delivery of a smoke modifying additive to a consumer 15 than convention smoking articles. Specific embodiments of the invention have been described, although the invention is not limited to such embodiments. For instance, although the second filter section has been described above as a tubular portion of fibrous filter material, this may take other 20 forms, such as filter material sections with lower density regions extending through an axial region thereof. Also, the tubular section or other section having reduced density in an axial region has been described as being at the mouth-end of the filter in some embodiments above, but in any of the embodiments can alternatively be used as a central or upstream end of multipart filters, for instance upstream of the section in 25 which the smoke modifying additive is located, while still benefiting from the effect of the invention. In particular, the presence of such a filter section can encourage mainstream smoke to be directed to an axial region of a smoking article both upstream and downstream of the region, due to the lower resistance to draw coinciding with the axial region. 30 The first, second and (where present) third filter sections described above are discrete segments. Although the first, second and (where present) third filter sections described above are connected together using tipping material, they are individually separate and distinct following their formation and prior to being connected together. The tipping 35 material also connects the filter sections to the respective tobacco rod of each embodiment. In alternative examples of each of the described embodiments, a further WO 2014/068295 PCT/GB2013/052813 - 16 plug wrap can be used to connect the first, second and (where present) third discrete filter sections before they are connected to the tobacco rods using the tipping material. In order to address various issues and advance the art, the entirety of this disclosure 5 shows by way of illustration various embodiments in which the claimed invention(s) may be practiced and provide for superior delivery of a smoke modifying additives. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that 10 advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, 25 consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.