KR20190078658A - Ventilated smoking article including sorbent material - Google Patents

Abstract

The smoking article 10 comprises a tobacco rod 12; And a filter 14 connected to the tobacco rod, the filter being surrounded by a filter wrapper 18 in which one or more filter segments 16 comprise adsorbent material 20. [ The filter comprises a ventilation zone (24) and is provided upstream of the adsorbent material (20). The level of the gaseous smoke component of the mainstream that is transmitted when smoking the smoking article 10 in which the ventilation area 24 is open is the level of the mainstream gas to be delivered when the smoking article 10 which blocks the ventilation area 24 is smoked It is within 40% of the level of the meteoric smoke component.

Description

[0001] Ventilated smoking article including sorbent material containing adsorbent material [0002]

The present invention relates to a ventilated smoking article wherein the adsorbent is bonded to a filter wrapper.

Typically, the filter cigarette is composed of a cigarette tobacco rod surrounded by a paper wrapper, a packed tobacco rod, and a cylindrical filter arranged at the end of the cigarette but the filter is attached to the cigarette rod by a tipping paper. In a typical filter cigarette, the filter may consist of a plug of cellulose acetate tow packaged in a porous plug wrap.

Typically, the vent area includes vents provided at one or more locations along the filter of the smoking article, and some vents may be accidentally blocked by, for example, the user's lips or fingers during smoking. As a result, the air entering the filter is disturbed and the mainstream dilution level is lowered.

In addition to the inclusion of a ventilation area, it is known to provide an adsorbent material such as activated carbon as an additional means in the filter of a smoking article to reduce the level of any smoke constituents. However, the adsorbent material can adversely affect the taste of mainstream smoke in a manner harmful to some users.

It is hoped that a new filter arrangement will be provided for a smoking article in which the delivery level of any smoke component is substantially maintained, even if the vent area is open or blocked. Thus, accidentally covering the ventilation area does not significantly affect the delivery of smoke components. It would also be desirable to be able to easily fabricate such a filter arrangement using existing equipment and techniques.

The present invention relates to a tobacco rod; And a filter connected to the tobacco rod and surrounded by a filter wrapper in which at least one filter segment comprises adsorbent material. The filter includes a vent area provided upstream of the adsorbent material. The result of this arrangement is that the level of the meteoric smoke component of the mainstream which is delivered when smoking the smoking product with the ventilation area open is the meteoric smoke component of the mainstream delivered when smoking the smoking product with the ventilation area blocked Is within 40% of the level of < / RTI >

 Ventilation areas are associated with the arrangement of vents or ventilation holes, which are provided in the filter, which dilutes the ventilation and mainstream smoke of the filter by suction of air entering the filter through the holes during smoking.

The vent area is referred to as "open" when it is not completely covered and the air is free to enter the filter during smoking. When the ventilation area is covered or sealed, it is called "blocking" and air is prevented from entering the filter through the ventilation area. In the context of the present invention, the level of the gaseous mainstream component delivered during smoking of the smoking article when the ventilation area is blocked is less than the level of the same vapor mainstream component delivered during smoking of the smoking article when the ventilation area is open %. Preferably, the level of the gaseous smoke component delivered to the vented vent area is within 30% of the level delivered to the vented vent area. , More preferably within 20%, and most preferably within 10%.

In the context of the present invention, the term "smoke constituent" refers to a gaseous constituent in the mainstream smoke, and in particular the smoke constituent here is a gaseous carbonyl compound comprising aldehydes and ketone compounds. For example, the gas phase component may comprise one or more formaldehyde, acetaldehyde, acetone and acrolein.

For the purposes of the present invention, the level of the main stream smoke component delivered during smoking of the smoking article according to the present invention with the ventilation area open is determined by the ISO condition (35 ml puff for 2 seconds every 60 seconds) It can be determined by smoking. In the ISO test method, the smoking article is smoked without completely covering the ventilation area. For purposes of the present invention, the level of the main stream smoke component is expressed per mg of nicotine, since the transfer of nicotine is standard.

The level of the mainstream meteoric smoke component delivered during smoking of the smoking article according to the present invention with the ventilation area blocked is determined by smoking a smoking article in the Health Canada test method (55 ml puff for 2 seconds every 30 seconds) . In the Health Canada test method, the tipping paper is covered with an air-impermeable film or tape so that air can not enter the filter through the ventilation area and the mainstream dilution is approximately 0%. As above, for purposes of the present invention, the level of the mainstream component is expressed per mg of nicotine, since the delivery of nicotine is standard.

The level of the gaseous smoke component in mainstream smoke is determined by averaging the samples of 20 smoking products that open the ventilation area and 20 smoking products that block the ventilation area. The level of smoke constituents is measured by the total amount of carbonyl compounds.

The present invention provides an effective method of maintaining a relatively constant delivery of a gaseous smoke component in a ventilated smoking article, regardless of whether it is opening or blocking the vent area.

In the present invention, the adsorbent material is contained within the filter of the smoking article. Thus, under normal smoking conditions where the ventilation area is open, dilution of the mainstream by the air entering the filter through the ventilation area will be the main mechanism for reducing the level of smoke constituents in the mainstream smoke. The venting air will provide air cushioning which will isolate a large amount of mainstream smoke from the adsorbent. Here, the adsorbent will have a slight effect on the level of the mainstream smoke component and flavor when opening the vent area.

Conversely, if the ventilation area is completely cut off, air is prevented from entering the filter and mainstream dilution is prevented. As a result, the flow of the mainstream passing through the filter changes and the smoke passes over the adsorbent and some gaseous components are absorbed by the adsorbent. In this case, the absorption of the smoke constituent will be the main mechanism for reducing the level of smoke constituents in the mainstream smoke.

In some cases, when the vent area is partially blocked, a reduction in the smoke content in the mainstream by both mainstream dilution and adsorbent may be realized. The arrangement of the adsorbent and the vent area depends on the balance between the reduction of the gaseous fume component by dilution and the reduction of the same gaseous fume component by the adsorbent. Here, such balance will automatically shift depending on how much the vent area is blocked. If the dilution level is reduced by blockage of the ventilation area, the adsorption of the smoke constituents by the adsorbent material will increase as a compensation for the lower dilution. Thus, the total level of smoke constituents may be kept as small as possible, regardless of whether the ventilation area is open, partially blocked or completely blocked.

The balance between the mainstream dilution level achieved by the ventilation zone and the adsorption of the mainstream constituents by the adsorbent at the surface of the filter wrapper is not limited, but may vary depending on the location and distribution of the ventilation zone, By adjusting the parameters of the filter such as the level of dilution achieved by the zone, the location, distribution and amount of the adsorbent provided therein, and the like. For example, the number and location of ventilation areas and the amount and location of adsorbent can be adjusted. So the delivery of the meteoric smoke component is the same whether the vent area is open or blocked.

In the filter of the smoking article according to the invention, the vent area may be provided upstream of most or all of the adsorbent material. In this arrangement, the flow of the mainstream in the filter will vary depending on how much air has entered the filter from the vent area. With the vent area open, venting air enters the filter, generally outside the filter material, while entraining flow of the mainstream towards the center of the filter. Thus, air entering through the ventilation area provides an outer, coextensive layer that effectively isolates and protects the mainstream from the adsorbent contained in the filter wrapper. In this way, the mainstream does not make much contact with the adsorbent. At normal smoking of the smoking product, the adsorbent will have a slight effect on mainstream smoke.

The vent is in the 'upstream' of the adsorbent material, which means that ventilation is provided at the mouth end of the smoking article rather than the adsorbent. During smoking, the main stream enters the downstream end of the filter at the upstream end from the upstream end near the combustion end of the tobacco rod through the smoking article. The mainstream will therefore first pass through the vent area before reaching the adsorbent in the filter wrapper.

Preferably, the vent area is one or more rows of vent openings and extends circumferentially along the periphery of the filter. In some embodiments, the rows of vents may be provided spaced along the filter, e.g., at least 5 mm or at least 10 mm apart from each other. This arrangement means that air enters the filter at different locations during smoking and can help maintain a constant air layer between the mainstream and the adsorbent along the length of the adsorbent. In this case, the best upstream vent area may be upstream of all or most of the adhesive.

If the vent area is blocked, the amount of air entering the filter will be reduced and substantially no air will enter the filter if the vent area is completely blocked. If there is no air layer outside of the filter, the mainstream will no longer be trapped in the central portion of the filter, and the smoke flowing through the outside of the filter will come into contact with the adsorbent contained in the filter wrapper. A small amount of air enters through the filter, a large amount of mainstream smoke comes into contact with the adsorbent, and the adsorbent will remove a large amount of smoke constituents.

If the vent area is partially blocked, the flow of air and smoke through the filter will be a combination of the two flow patterns depending on the relative position of the vent area blocked on the filter and the blocking area. For example, if a portion of the venting region at the mouth end of the filter is blocked but the remaining upstream venting region is open, then the mainstream will initially be separated from the adsorbent by the air layer outside the filter, As the venting air and smoke mix, a lot of smoke will come into contact with the adsorbent.

Preferably, the ventilation area is diluted between 10% and 80% of the mainstream smoke. Where 'dilution' refers to the percentage of air volume contained in the smoke delivered to the user from the mouth end of the filter with the ventilation area fully open. More preferably, the vent area is diluted with between 30% and 70% of the mainstream. Particularly preferably between 50% and 80%. The level of ventilation or dilution achieved by the ventilation area can be determined using ISO Test Method 9512: 2002.

The ventilation level can be adjusted by controlling the thickness of the concentric air layer, which preferably flows through the outer concentric region of the filter and separates the mainstream from the adsorbent. The thicker the air layer from the outside of the filter, the more effective the air layer will be to protect the mainstream from the adsorbent. This will also reduce the effect of the adsorbent on the flavor of the smoke delivered to the user when smoking while opening the vent area. As a further variant, it is possible to set the ventilation level through the ventilation area and adjust the amount of adsorbent. So the opening or blocking of ventilation areas or the delivery of meteorological components is similar.

Preferably, the uppermost portion of the ventilation region is provided between 20 mm and 30 mm from the mouth end of the smoking article. Preferably, the best upstream portion of the vent area is at least 2 mm from the filter rod front. Here, the filter is adjacent to the tobacco rod. The position of this vent area is on the side of the tobacco rod away from the mouth end of the filter and there is an increase in the usable area to place the adsorbent downstream of the vent area.

The vent area is provided on all adsorbent materials, or substantially all upstream of the adsorbent material. Although it is preferred that the vent area be provided upstream of all the adsorbent material, although the ordinary skilled artisan will appreciate that even though the location of the vent area is provided at a small percentage, most of the adsorbent is downstream of the vent area or upstream of the vent area. It will be understood that the desired effect can be achieved. The vent area provides at least 80% upstream of the adsorbent.

The adsorbent material may be in the form of any suitable adsorbent or adsorbent material. Various adsorbents suitable for use in smoking articles are already well known to those of ordinary skill in the art. Suitable adsorbents include, but are not limited to, activated carbon, zeolites, sepiolite, alumina, molecular sieves, and combinations thereof. In a particularly preferred embodiment, the adsorbent is activated carbon.

In a preferred embodiment, the filter wrapper of the smoking article according to the invention is formed by applying a layer of adsorbent on the surface of the filter wrapper. Preferably, the amount of adsorbent in the layer is at least about 20 mg. The amount of adsorbent is preferably not more than 120 mg, more preferably not more than about 100 mg, most preferably not more than about 60 mg. Particularly preferably, the amount of adsorbent is between about 20 mg and about 120 mg, more preferably between about 40 mg and about 60 mg.

The adsorbent material is preferably provided in the form of an adsorbent of particles or granules. This is preferable for application to the adhesive layer or binder at the surface of the filter wrapper. The adsorbent may also be provided as a separate layer located on the surface of the filter wrapper. The adsorbent material may also be applied as a separate layer to the outer surface of the filter segment and the filter wrapper may wrap the adsorbent layer to bring the surface of the filter wrapper into contact with the adsorbent.

In addition to or in addition to the conditions of the adsorbent material in the layer on the surface of the filter wrapper, the adsorbent material can be incorporated outside of the filter material itself. For example, the filter can be made of a plug of a fibrous filter material, such as a cellulose acetate tow, and a special adsorbent can be provided in a concentric, outer layer, e.g., concentric, outer layer of the filter tow, . The adsorbent may be uniformly provided to the concentric outer layer of the filter tow or it may be a concentrated component of the adsorbent in the filter. Where the proportion of adsorbent in the filter tow increases to be directed towards the outside of the filter.

In addition to or as an alternative to the arrangement of adsorbents mentioned above, the adsorbent can be incorporated into the sheet material forming the filter wrapper. For example, the adsorbent may be incorporated into the paper material during the manufacturing process of the material.

When the adsorbent material is on one surface of the filter wrapper, it is preferred that the adsorbent material comprises at least 50%, more preferably at least 60%, of the outer or inner surface of the filter wrapper. The adsorbent material may be provided in a single zone over the surface of the filter wrapper or in the form of a pattern applied to the surface of the filter wrapper in a plurality of zones, for example.

It may be desirable for the adsorbent material to be provided on the inner surface of the filter wrapper. Here, the 'inner' surface refers to the radially inner surface of the wrapper proximate the filter segment. On the other hand, however, it may be effective to add an adsorbent to the outer surface of the wrapper as an additional or other deformation to the adsorbent on the inner surface, if mainstream smoke can come into contact with the adsorbent upon smoking. For example, when the filter wrapper is porous and air permeable, the adsorbent may be provided on either or both of the inner and outer surfaces, so that mainstream smoke will be able to contact both sides during smoking.

In a preferred embodiment of the present invention, the filter wrapper to which the adsorbent is applied is a plug wrap that surrounds the filter along at least a portion of its length. The adsorbent can be applied to the inner layer of the plug wrap and the inner surface comes into contact with the underlying filter material.

In some cases, the filter is packaged in a second layer of the flag wrap, for example the plug wrap layer joins other segments of the multi-component filter. In addition to the adsorbent in the inner layer of the plug wrap, the adsorbent material may also be applied to the second layer of plug wrap that is placed on one or more inner layers of the air-permeable plug wrap. The adsorbent material may be applied to the area of the inner surface of the second layer of plug wrap. The adsorbent material may also be applied to the outer surface of the second layer of plug wrap. In particular, the second layer of plug wrap will form a substantially air-permeable sheet material. So that the main stream can easily penetrate through the second layer of plug wrap to make contact with the adsorbent.

In another preferred embodiment of the present invention, the filter wrapper to which the adsorbent is applied is a tipping wrapper, such as a tipping paper, which surrounds the filter and connects the filter to the tobacco rod. Here, the adsorbent material is provided on the tipping paper. The material should be applied to the inner surface of the tipping wrapper so that it is not exposed to the outside of the filter.

The filter of the smoking article according to the invention may comprise one filter segment. In addition, the filters may consist of two or more filter segments in axial alignment with one another. The filter segments or segments may be of various shapes and suitable filter segments are well known to those of ordinary skill in the art. Where two or more filter segments are included, the filter segments may be of the same construction and material. It may also have other structures or have other filtration materials or additives. Preferably, the filter segments or segments are each formed of a plug fibrous filtration material, such as a cellulose acetate tow or paper, and packaged in a plug wrap.

The one or more filter segments may comprise special materials. It may be desirable to incorporate the special material into the upstream filter segment, e.g., the rod end filter segment.

Special materials may be dispersed through plugs of fibrous filtration material such as cellulose acetate or paper. Preferably, the special material can be applied to the fibrous filter material by spraying the filter plasticizer onto separate fibers in a conventional manner prior to application to the filter material. In addition, the filter may comprise a filter segment having a hollow cavity at least partially filled with a special material. In this case, the hollow cavity is preferably provided between the plugs of the two filtration materials.

The special material incorporated into the filter may comprise at least one adsorbent material as mentioned above for inclusion in the filter wrapper. Here, the adsorbent is incorporated into the filter, and the amount of adsorbent in the filter must be less than the amount of adsorbent contained in the filter wrapper. So that the performance characteristics of the filter can be maintained.

In addition, the special material incorporated into the filter may comprise at least one flavor material. For example, the special material may include adsorbents or particles of cellulosic material in liquid flavor such as menthol. Further, the particle material may be composed of particles of a plant material. The plant material may be in the form of a plant leaf as described in EP-A-1,958,523. For example, the filter segments may include leaves from mints such as tobacco, green tea, peppermint or spearmint, laurel, eucalyptus, basil, sage, verbena and tarragon. The plant material may also be in the form of seeds, roots or flowers, such as those commonly used as spices.

In addition, the one or more filter segments may have a liquid flavor such as menthol applied directly to the filtration material.

Preferably, the total length of the smoking article according to the invention is between about 70 mm and about 128 mm, for example about 84 mm.

Preferably, the outer diameter of the smoking article according to the invention is between about 5 mm and about 8.5 mm, more preferably about 7.9 mm.

Preferably, the total length of the filter of the smoking article according to the invention is between about 18 mm and about 36 mm, more preferably about 27 mm.

The smoking article of the present invention consists of a rod of tobacco material which is attached to the filter by a tipping wrapper. The load of the tobacco material may include each second taken from one or more types of tobacco, expanded tobacco, recombinant tobacco, or combinations thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
1 is a perspective view of a smoking article according to the present invention which is not wrapped with a filter.
Figure 2 is a side view of the smoking article of Figure 1, schematically illustrating the flow of air and smoke through the filter when the vent area is open.
Fig. 3 is a side view of the smoking article of Fig. 1, schematically illustrating the flow of smoke through the filter when the vent area is completely blocked. Fig.

The filter cigarette 10 of Fig. 1 is constituted by attaching the packing rod 12 of each cigarette angle to the filter 14 arranged in the axial direction. The tobacco rod 12 is packed in a cigarette paper (not shown). The filter 14 consists of one segment 16 and is formed of a plug of cellulose acetate tow. The filter segment 16 is wrapped in a plug wrap 18, which surrounds the entire length of the filter 14.

The plug wrap 18 is formed of a sheet of air-permeable paper material and includes an adsorbent layer 20. This adsorbent layer 20 occupies about 50% of the inner surface of the plug wrap 18. The adsorbent layer 20 is formed of a substantially uniformly dispersed layer of about 50 mg of special activated carbon and is attached to the inner surface of the plug wrap 18 by a suitable adhesive. In such an assembly filter, the adsorbent layer 20 extends circumferentially along the filter segment 16 and is in contact with the outer surface of the filter segment 16.

The wrapped tobacco rod 12 and the wrapped filter 14 are connected to each other by an outer tipping wrapper 22 which is attached to the tobacco rod 12 adjacent the entire length of the filter 14, As shown in FIG. And is placed on the plug wrap 18. The tipping wrapper 22 is formed as a tipping paper and is provided with a ventilation area in which a ventilation opening 24 extending in a circumferential direction along the filter 14 is arranged in a row. The row of vent openings 24 is located in the filter at the rod end of the filter segment 16 and is adjacent to the interface between the filter 14 and the tobacco rod 12. The entire surface of the adsorbent layer (20) is located downstream of the row of the ventilation openings (24). When the vents are opened, the ventilation area dilutes about 60% of the mainstream smoke during smoking.

Upon normal smoking of the filter cigarette 10, the vents will not be completely covered, and air will be forced into the filter 14 through the vents in the tipping wrapper 22, as in Fig. In Figure 2, the air flow is indicated by a white arrow and the mainstream flow is indicated by a black arrow. As will be seen, the air will be drawn along the filter 14 toward the mouth end of the filter 14 to form a concentric air layer 26 along the outside of the filter segment 16. The mainstream will enter from the tobacco rod and the presence of the air layer 26 will force the main stream towards the center of the filter segment 16 so that the mainstream will be separated from the inner surface of the plug wrap 18 by the air layer 26 . This is because when the ventilation hole is completely opened, the contact between the mainstream smoke and the activated carbon in the adsorbent layer 20 on the inner surface of the plug wrap 18 is restricted. Thus, the presence of the adsorbent layer 20 will not exert any effect on the level of the vapor phase component contained in the mainstream smoke. However, the air flowing through the filter 14 will dilute the mainstream to reduce the level of the meteorological components in the mainstream smoke that the consumer receives to about 60%.

The position of the row of vents 24 upstream of the adsorbent layer 20 ensures that the mainstream is directed from the outside of the filter segment 16 to the center of the filter before the mainstream reaches the filter segment portion where the adsorbent layer 20 starts Make sure that.

FIG. 3 illustrates a state in which all the ventilation holes 24 are completely blocked, and there is no air entering the filter 14 during smoking. Under these conditions, there is no dilution of the mainstream in the filter and there is no decrease in the gas phase component in the ventilation area. In the absence of the air layer 26, the mainstream is not collected at the center of the filter segment 16, but over the entire cross section of the filter segment 16, as schematically indicated by the arrows in Fig. 2, mainstream smoke comes into contact with the adsorbent layer 20 on the inner surface of the plug wrap 18 when the smoke is sucked through the filter 14. The activated carbon of the adsorbent layer 20 adsorbs some gas phase component from the mainstream smoke and the total level of these components in the smoke delivered to the user drops.

Under the circumstances as shown in Fig. 3, the level of the gas stream component (carbonyl compound) of the main stream is within about 40% of the level of the same gas phase component under the situation shown in Fig.

Indeed, during smoking, the user is unlikely to block all of the vents 24 in the tipping paper 22, so the situation illustrated in Figure 3 is likely to be only an experimental Health Canada smoking test Is high. Nevertheless, users may accidentally place their fingers around the filter, for example in the area of the ventilation area, so that when a part of the ventilation opening 24 is blocked, air can not enter the filter through ventilation holes covered by the fingers. In this case, the situation would correspond to the middle of the two embodiments shown in Figs. At this point, the air layer 26 will not extend around all the filters 14, and the mainstream will be in contact with the adsorbent layer 20 at a particular location.

Due to the partial blockage of the vent 24, the amount of air introduced into the filter will be reduced and the dilution of the mainstream will also be reduced, reducing the level of the gaseous constituents as a result of the dilution. However, the contact between the activated carbon in the adsorbent layer (20) and the mainstream lead to an increase in the decrease of the gas phase component by the adsorbent, so that the total level of the gas phase component will be within 40% as shown in FIGS. 2 and 3 .

Thus, it can be seen that due to the combination of dilution and adsorbent layer 20, the total level of the gas phase components in the mainstream is maintained relatively constant, whether the vent 24 is open, partially blocked, or totally blocked.

In the embodiments described above and shown in the drawings, the adsorbent layer is provided on the inner surface of the plug wrap, but the different placement of the adsorbent layer in the plug wrap and / or the tipping wrap may be advantageous, It can be said that it is possible to provide the same effect as the reduction of

10: filter cigarette
12: Tobacco rod (wrapper rod)
14: Filter
16: Filter segment
18: Plug wrap
20: adsorbent layer
22: Tipping wrapper
24: Vents
26: air layer

Claims (15)

Tobacco load; And
The filter comprising a filter connected to the tobacco rod and one or more filter segments surrounded by a filter wrapper comprising adsorbent material wherein the filter is provided upstream of the adsorbent material,
Wherein the adsorbent material and the ventilation area are within 40% of the level of the vapor phase constituent of the mainstream when the level of the vapor stream component of the mainstream is blocked by the ventilation area when the ventilation area is opened. The smoking article according to claim 1, wherein the level of the gaseous smoke component of the mainstream when the ventilation area is opened is within 20% of the level of the gaseous smoke component of the mainstream when the ventilation area is blocked. 3. A smoking article according to claim 1 or 2, wherein the ventilation area is formed by one or more vents extending in a line along the circumference of the filter. The smoking article according to any one of claims 1 to 3, wherein the rows of vents are spaced at least 5 mm apart from one another. The smoking article according to any one of claims 1 to 4, wherein the filter wrapper is a plug wrap or a tipping wrapper. 7. A smoking article according to any one of the preceding claims, wherein the filter wrapper is applied to at least a part of the inner surface of the filter wrapper. 6. A smoking article according to any one of claims 1 to 5, wherein the filter wrapper is substantially air permeable and the adsorbent layer is applied to at least a portion of the outer surface of the filter wrapper. 8. The smoking article of claim 6 or 7, wherein the filter wrapper is present between about 40 mg and about 60 mg of adsorbent material. 7. A smoking article according to any one of the preceding claims, wherein the adsorbent comprises at least 60% of one of the inner or outer surface of the filter wrapper. A smoking article according to any one of the preceding claims, wherein the adsorbent comprises a special adsorbent applied to the adhesive layer on the surface of the filter wrapper. A smoking article according to any one of the preceding claims, wherein the adsorbent material is made by incorporating a special adsorbent into the filter wrapper. 10. A smoking article according to any one of the preceding claims, wherein the filter comprises a segment of one or more fibrous filtering materials. The smoking article according to any one of the preceding claims, wherein the uppermost upstream portion of the ventilation area is provided between 20 mm and 30 mm from the mouth end of the smoking article. A smoking article according to any one of the preceding claims, wherein the ventilation area dilutes the mainstream smoke of the smoking article to between 30% and 70% when smoking in a fully open state. 10. A smoking article according to any one of the preceding claims, wherein the vent area provides at least 80% upstream of the adsorbent of the filter wrapper.

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