Smoking article provided with a flavor delivery member

Abstract

To provide a filter (103) for a smoking article (100).SOLUTION: A filter (103) comprises a filter segment (201) comprising a filter material, and the filter segment (201) has a cross sectional area measured perpendicularly to the longitudinal direction of the filter (103). The filter further comprises a flavor delivery member (205) embedded in the filter segment (201) and surrounded on all sides by the filter material (203). The flavor delivery member (205) comprises a structural material enclosing a liquid flavorant for flavoring smoke during smoking of a smoking article provided with the filter (103), and the flavor delivery member (205) releases at least a portion of the liquid flavorant when the filter (103) is subjected to external force. The cross sectional area of the flavor delivery member (205) measured perpendicularly to the longitudinal direction of the filter (103) is about 30% of the cross sectional area of the filter segment (201) or greater.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to filters for smoking articles and smoking articles provided with such filters.

Background Art

[0002] Combustible smoking articles such as cigarettes typically comprise finely cut tobacco (usually in the form of cut filler) surrounded by a paper wrapper that forms a tobacco rod. The cigarette is ignited at one end and the finely cut tobacco rod is burned for use by a consumer. The consumer then inhales the mainstream smoke by drawing at the opposite end of the cigarette (the mouth end or filter end). The finely cut tobacco may be a single type of tobacco or a blend of two or more types of tobacco.

[0003] Numerous smoking articles in which the aerosol-forming substrate such as tobacco is heated rather than burned have also been proposed in the art. In heated smoking articles, the aerosol is generated by heating the aerosol-forming substrate. Known heated smoking articles include, for example, smoking articles in which the aerosol is generated by electrical heating or by the transfer of heat from a combustible fuel element or heat source to the aerosol-forming substrate. During smoking, volatile compounds are released from the aerosol-forming substrate by heat transfer from the heat source and entrained in the air drawn through the smoking article. As the released compounds cool, they condense to form an aerosol which is inhaled by the consumer. Also known are smoking articles in which nicotine-containing aerosol is produced from a tobacco material, tobacco extract, or other nicotine source without combustion and in some cases without heating, for example by chemical reaction.

[0004] Smoking articles, particularly cigarettes, typically comprise a filter aligned with a tobacco rod or another aerosol-forming substrate in an end-to-end relationship. The filter typically includes a plug of cellulose acetate tow attached to the tobacco rod or aerosol-forming substrate by tipping paper. Ventilation of the mainstream smoke can be achieved by one or more rows of perforations located near the position along the filter within the tipping paper.

[0005] Flavors can be added to cigarettes and smoking articles. Some consumers may prefer cigarettes that can selectively provide one or more flavors in response to the immediate desires of the consumer, whether short-term or long-term. However, certain flavorants are volatile and tend to evaporate or migrate over time, reducing the effectiveness of these flavorants.

[0006] Accordingly, it is desirable to provide a smoking article and a filter for a smoking article that promotes the transfer of flavor to the smoke, minimizes the diffusion of the flavor, and still maintains other desirable characteristics of the smoking article. SUMMARY OF THE INVENTION

[0007] According to a first aspect of the present invention, there is provided a filter for a smoking article, the filter comprising a filter segment including a filter material, the filter segment having a cross-sectional area measured perpendicular to the long axis of the filter, and a flavor delivery member embedded within the filter segment and surrounded on all sides by the filter material, the flavor delivery member comprising a structural material that encapsulates a liquid flavorant for flavoring the smoke during smoking, the flavor delivery member releasing at least a portion of the liquid flavorant when the filter is subjected to an external force, and the cross-sectional area of the flavor delivery member measured perpendicular to the long axis of the filter being at least about 30% of the cross-sectional area of the filter segment, and the filter material of the filter segment having a denier per filament of from about 5.0 to about 12.0 and comprising fibers having a total denier of from about 10,000 to about 35,000.

[0008] External forces can act in any direction, but it is preferred that they act in a direction perpendicular to the major axis direction of the filter. One preferred method of applying an external force is for the user to compress the filter containing the flavor delivery member or apply an external force to the filter before or during smoking a smoking article containing the filter. By the action of compression or squeezing or the application of an external force, it is preferred that the flavor delivery member is broken, whereby at least a portion of the liquid flavorant is released into the filter. As another method, the action of compression or squeezing can provide for a continuous release of the liquid flavorant over a range of compressive forces. The liquid flavorant can then flavor the smoke passing through the filter. External devices such as pinching devices, tube compression devices, tweezers or any other device for applying a compressive force can also be used to concentrate the force at a predetermined filter location.

[0009] The cross-sectional area of the flavor delivery member is larger than that of the prior art filters when compared to the cross-sectional area of the filter segment. Since the cross-sectional area of the flavor delivery member is at least about 30% of the cross-sectional area of the filter segment, less than about 70% of the cross-sectional area of the filter segment remains permeable to air and smoke. Thus, in the filter of the present invention, the flavor delivery member has a higher blocking effect than prior art filters. This leads to several effects that are different from those seen in prior art filters and can be advantageous. First, the filter can have a higher draw resistance (RTD) than prior art filters before the flavor delivery member releases the liquid flavorant. This is because the air and smoke flow through the filter segment is forced to pass through a relatively small area of the filter material around the flavor delivery member. Such a high RTD can create a new and novel sensory experience for the consumer. Second, when the filter is subjected to an external force and the flavor delivery member releases the liquid flavorant (e.g., when the flavor delivery member is damaged), the cross-sectional area of the filter segment that is permeable to the gas flow increases, resulting in a sudden flow of air and smoke through the filter. That is, there is a decrease in the RTD (from the relatively high starting RTD), and there is also a noticeable change in flavor due to the liquid flavorant. Again, a stimulating sensory experience that enhances the mood is created for the consumer.

[0010] Thirdly, since the dimensions of the flavor delivery member are large compared to the dimensions of the filter segment, the flavor delivery member is subject to damage during manufacturing or handling (because the flavor delivery member is close to the outside of the filter). However, the inventors of the present invention have come to understand that by embedding the flavor delivery member within the filter material, the flavor delivery member is better protected during manufacturing and handling. The flavor delivery member is retained within the filter material. However, it is still possible for the consumer to locate the position of the flavor delivery member within the filter and apply the necessary external force so that the liquid flavorant is released. Thereby, the filter of the present invention allows the use of a larger flavor delivery member (relative to the dimensions of the filter) than would be possible when used within a recess in a filter such as, for example, a "plug-space-plug" filter. By embedding the flavor delivery member within the filter material of the filter segment, the flavor delivery member can be incorporated between the fibers of the filter material tow, adding the advantage that the manufacturing can be made simpler. Thus, conventional manufacturing techniques can be used where a continuous tow material with the flavor delivery member embedded therein is cut into filter segments. No separate step for inserting the flavor delivery member is required.

[0011] According to the present invention, the filter material of the filter segment is appropriately selected to achieve a desired balance of RTD (including the RTD before and after the release of the liquid flavorant), an appropriate amount of material for properly retaining the flavor delivery member within the filter segment, and an appropriate amount of material for preventing the filter material from deforming around the flavor delivery member.

[0012] In particular, the filter material of the filter segment includes fibers of about 5.0 to about 12.0 denier per filament, with a total of about 10,000 and about 35,000 denier. The total density of such filter material is lower than that of filter materials in the prior art in which flavor delivery members are embedded. This can provide a desired RTD, while on the other hand, it can provide an appropriate amount of material to avoid swelling of the filter material around the flavor delivery member while supporting the flavor delivery member.

[0013] The filter segment preferably contains fibers of 6.0 denier per filament (dpf) or more. In one desirable embodiment, the filter segment contains large diameter fibers of about 8.0 dpf. The total denier of the filter segment is preferably less than about 30,000, more preferably less than about 25,000. Further, or alternatively, the total denier of the filter segment is preferably greater than about 12,000. In one desirable embodiment, the filter segment contains large diameter fibers with a total denier of about 15,000. The number of fibers present in the filter segment (total denier ÷ dpf) can be less than about 6,000, but is preferably less than about 5,000. It has been found that such filter materials provide an appropriate balance while avoiding deformation of the filter material when the flavor delivery member is embedded within the filter material (between the RTD and the flavor delivery member support).

[0014] A further advantage provided by using the filter material according to the present invention is that it facilitates the embedding of the flavor delivery member within the filter material. The inventors have understood that by embedding the flavor delivery member in a filter material with a relatively low total density, even if the flavor delivery member is close to the outer surface of the filter, the flavor delivery member is protected during manufacturing and handling. By using a filter material with a low total density, the flavor delivery member can be embedded without causing deformation (e.g., swelling) in the filter. The low density material effectively provides voids for the flavor delivery member incorporated into the filter material. At the same time, the filter material provides fibers that release flavor at the outer tip of the filter and promote the uptake of flavor by the smoke.

[0015] Another further advantage provided by using the filter material according to the present invention is that in the case of a slim cigarette with a diameter of about 6.0 mm or less, a low density filter material can achieve standard tar delivery levels and maximize flavor even when such smoking articles contain relatively little tobacco.

[0016] As already discussed, according to the filter of the present invention, the cross-sectional area of the filter blocked by the flavor delivery member is larger than that in the prior art. Thus, a smoking article using such a filter can have a higher RTD than prior art smoking articles before the liquid flavorant is released. Such a high RTD can create a new and novel sensory experience for the consumer. The RTD of the smoking article can be about 130 mm H2O or more before the liquid flavorant is released, preferably about 150 mm H2O or more. Further, or alternatively, the RTD of the smoking article can be about 210 mm H2O or more. The RTD of the smoking article is preferably from about 130 mm H2O to about 210 mm H2O, more preferably from about 150 mm H2O to about 210 mm H2O.

[0017] Furthermore, there is a decrease in RTD when the flavor delivery member is crushed, which can create a new and novel sensory experience for the consumer. The decrease in RTD can be due to the size of the flavor delivery member becoming smaller when crushed. The RTD of the smoking article can decrease by at least about 10 mm H2O after the flavor delivery member is crushed, preferably by at least about 20 mm H2O, more preferably by at least about 30 mm H2O.

[0018] As used herein, the terms "upstream" and "downstream" are used to describe the relative position between elements of the filter or smoking article with respect to the direction of the mainstream smoke when the mainstream smoke is drawn through the filter from the ignited end of the smoking article.

[0019] As used herein, the phrase "surrounded on all sides" means that the flavor delivery member is directly adjacent to the filter material of the filter segment in the upstream and downstream directions (the major axis direction) and in the transverse direction. That is, the flavor delivery member is completely embedded within the filter material and not in a separate recess. The flavor delivery member is preferably incorporated into the filter material during the manufacture of the filter material. For example, the flavor delivery member can be incorporated between the fibers of a continuous rod of filter material and then cut into filter segments later.

[0020] The cross-sectional area of the flavor delivery member measured perpendicular to the major axis of the filter is at least about 30% of the cross-sectional area of the filter segment measured perpendicular to the major axis of the filter. Alternatively, stated in another form, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is less than about 70%. (When the filter includes a wrapper such as plug wrap or tipping paper, the cross-sectional area of the filter segment is generally measured within the wrapper.) The cross-sectional area of the flavor delivery member is preferably at least about 30% of the cross-sectional area of the filter segment and can be less than about 80%. Alternatively, stated in another form, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is preferably at least about 20% and less than about 70%.

[0021] The cross-sectional area of the flavor delivery member measured perpendicular to the major axis direction of the filter is more preferably at least about 45% of the cross-sectional area of the filter segment. Alternatively, in another form of expression, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is less than about 55%. The cross-sectional area of the flavor delivery member is preferably at least about 45% of the cross-sectional area of the filter segment and can also be less than about 80%. Alternatively, in another form of expression, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is preferably at least about 20% and less than about 55%.

[0022] The cross-sectional area of the flavor delivery member measured perpendicular to the major axis direction of the filter is more preferably at least about 55% of the cross-sectional area of the filter segment. Alternatively, in another form of expression, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is less than about 45%. The cross-sectional area of the flavor delivery member is preferably at least about 55% of the cross-sectional area of the filter segment and can also be less than about 80%. Alternatively, in another form of expression, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is preferably at least about 20% and less than about 45%.

[0023] The diameter of the filter is preferably less than about 6.5 mm. The diameter of the filter is more preferably from about 3.6 mm to about 6.5 mm. (The diameter of the filter is generally measured within any wrapper material such as plug wrap or tipping paper unless otherwise indicated herein.) The diameter of the filter is more preferably from about 3.6 mm to about 5.5 mm. The diameter of the filter is even more preferably from about 3.6 mm to about 4.5 mm.

[0024] The length of the filter can be about 27 mm, and the center of the flavor delivery member can be located about 13.5 mm from the downstream end of the filter. In that case, if the filter segment is the only component of the filter, the center of the flavor delivery member is located about 13.5 mm from the downstream end of the filter segment, or if the filter includes additional filter elements, the center of the flavor delivery member is located about 13.5 mm from the downstream end of the filter, which may or may not be the downstream end of the filter segment. Alternatively, the length of the filter can be about 32 mm, and the center of the flavor delivery member can be located about 16 mm from the downstream end of the filter. In that case, if the filter segment is the only component of the filter, the center of the flavor delivery member is located about 16 mm from the downstream end of the filter segment, or if the filter includes additional filter elements, the center of the flavor delivery member is located about 16 mm from the downstream end of the filter, which may or may not be the downstream end of the filter segment. As used herein, the "center" of the flavor delivery member means the midpoint between the most downstream portion and the most upstream portion of the flavor delivery member.

[0025] The flavor delivery member can be positioned symmetrically or asymmetrically within the filter. When the flavor delivery member is positioned symmetrically within the filter, the center of the flavor delivery member is equidistant between the upstream and downstream ends of the filter. The filter can include one or more additional filter elements upstream of the filter segment, downstream of the filter segment, or both upstream and downstream of the filter segment. When the filter includes additional elements and the placement of the flavor delivery member is symmetric with respect to the entire filter, the placement of the flavor delivery member can be either symmetric or asymmetric with respect to the filter segment, depending on the position and length of the additional filter elements. When the flavor delivery member is positioned asymmetrically within the filter, the center of the flavor delivery member is not equidistant between the upstream and downstream ends of the filter. For example, the flavor delivery member can be positioned in the upstream third or the downstream third of the filter. When the filter includes additional elements and the placement of the flavor delivery member is asymmetric with respect to the entire filter, the placement of the flavor delivery member can be either symmetric or asymmetric with respect to the filter segment, depending on the position and length of the additional filter elements.

[0026] In one preferred embodiment, the filter segment and the flavor delivery member are circular in cross-section, the diameter of the filter segment is from about 3.6 mm to about 6.5 mm, and the diameter of the flavor delivery member measured perpendicular to the long axis of the filter is from about 2.5 mm to about 4.5 mm. For example, the diameter of the filter segment (inside any filter wrapper) can be about 6.1 mm. For example, the diameter of the flavor delivery member can be about 3.5 mm. In this embodiment, the cross-sectional area of the flavor delivery member measured perpendicular to the long axis of the filter is about 33% of the cross-sectional area of the filter segment. Alternatively, put another way, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is about 67%. For a "slim cigarette" with an overall diameter of about 7.0 mm, a filter with a diameter of about 6.1 mm can be used.

[0027] In another preferred embodiment, the filter segment and the flavor delivery member are circular in cross-section, the diameter of the filter segment is from about 3.6 mm to about 5.5 mm, and the diameter of the flavor delivery member measured perpendicular to the long axis of the filter is from about 3.0 mm to about 3.5 mm. For example, the diameter of the filter segment (inside any filter wrapper) can be about 4.5 mm. For example, the diameter of the flavor delivery member can be about 3.2 mm. In this embodiment, the cross-sectional area of the flavor delivery member measured perpendicular to the long axis of the filter is about 51% of the cross-sectional area of the filter segment. Alternatively, in another form of expression, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is about 49%. For a "super slim cigarette" with an overall diameter of less than about 5.4 mm, a filter with a diameter of less than about 4.5 mm can be used.

[0028] In another preferred embodiment, the filter segment and the flavor delivery member are circular in cross-section, the diameter of the filter segment is from about 3.6 mm to about 4.5 mm, and the diameter of the flavor delivery member measured perpendicular to the long axis of the filter is from about 3.0 mm to about 3.5 mm. For example, the diameter of the filter segment (inside any filter wrapper) can be about 3.8 mm. For example, the diameter of the flavor delivery member can be about 3.2 mm. In this embodiment, the cross-sectional area of the flavor delivery member measured perpendicular to the long axis of the filter is about 71% of the cross-sectional area of the filter segment. Alternatively, in another form of expression, the ratio of the cross-sectional area of the filter segment that remains permeable to air and smoke after the flavor delivery member is embedded in the filter material is less than about 29%. For a "micro slim cigarette" with an overall diameter of about 4.7 mm, a filter with a diameter of about 3.8 mm can be used.

[0029] The term "flavor delivery member" means any delivery system that delivers flavor, and in this case, includes a structural material that encapsulates a liquid flavorant. By providing a flavor delivery member that releases the liquid flavorant when the filter is subjected to an external force, the liquid flavorant is released in a manner that can be controlled by the consumer. An external force can be applied before or during the use of the smoking article, thereby releasing the liquid flavorant. The external force on the flavor delivery member causes the liquid flavorant to escape from the flavor delivery member and interact with the smoking article to change its characteristics, and thus smoke is derived therefrom. Since the liquid flavorant is released only when an external force is applied to the filter, this reduces the likelihood of the liquid flavorant diffusing or decomposing, for example, during storage.

[0030] The flavor delivery member can be of any desirable size as long as the cross-sectional area of the flavor delivery member measured perpendicular to the major axis of the filter is at least about 30% of the cross-sectional area of the filter segment. For example, the flavor delivery member can be spherical with a diameter of about 2.5 mm to about 4.5 mm, preferably about 3.0 mm to about 3.5 mm. Alternatively, the flavor delivery member is spherical with a diameter of less than about 3.4 mm, preferably about 3.2 mm.

[0031] In the case of a small flavor delivery member, numerous manufacturing challenges can be raised. By using a flavor delivery member having a cross-sectional area of at least about 30% of the cross-sectional area of the filter segment, in some embodiments, such manufacturing challenges can be avoided. A relatively large flavor delivery member with respect to the filter segment maximizes the amount of liquid flavorant encapsulated within the flavor delivery member, and the consumer can achieve a desired flavor level. In the case of a flavor delivery member having an outer shell and an inner core, a relatively large flavor delivery member also includes a proportionally thicker outer shell. Such shells are relatively simple for consistent manufacturing and for manufacturing with a desired burst strength.

[0032] The flavor delivery member can have any suitable structure in which the structural material confines the liquid flavorant. The flavor delivery member can comprise a substrate structure that defines a number of regions, but the liquid flavorant is confined within the regions until it is released when an external force is applied to the filter. However, it is more preferable for the flavor delivery member to comprise a capsule. The capsule preferably comprises an outer shell and an inner core containing the liquid flavorant. The outer shell is preferably substantially continuous. The outer shell is preferably sealed before the external force is applied, but is brittle and easily broken so that the liquid flavorant is released when the external force is applied. The capsule can be formed of various physical formations, including, but not limited to, capsules consisting of a single part, capsules consisting of multiple parts, capsules consisting of a single wall, capsules consisting of multiple walls, large capsules, and small capsules.

[0033] When the flavor delivery member comprises a substrate structure that defines a plurality of regions for confining the liquid flavorant, the flavor delivery member can release the liquid flavorant when the filter is exposed to an external force of at least more than 5 N in the force range. The force of the flavor delivery member against the compression curve can have a peak of about 5 N to about 24 N. Alternatively, when the filter is exposed to an external force (for example, but not limited to, when the capsule comprises a shell and an inner core), if the flavor delivery member is a capsule arranged to rupture or break to release the liquid flavorant, the capsule can have a desirable rupture strength. The rupture strength is the force at which the capsule (acting on the capsule from the outside of the filter) ruptures. The rupture strength can be the peak in the force of the capsule against the compression curve. The capsule preferably has a rupture strength of about 5 N (0.5 kgf) to about 24 N (2.4 kgf). More preferably, the capsule has a rupture strength of about 8 N (0.8 kgf) to about 20 N (2.0 kgf). Even more preferably, the capsule has a rupture strength of about 12 N (1.2 kgf) to about 16 N (1.6 kgf).

[0034] The flavor delivery member can have any suitable shape, for example, spherical, spheroidal, or ellipsoidal. However, the flavor delivery member is generally preferably spherical. This can include flavor delivery members with a sphericity value of at least about 0.9, although the sphericity value is preferably approximately 1. Sphericity is a measure of how spherical an object is, and the sphericity value for a perfect sphere is 1. The sphericity value can be determined by finding the average of the maximum diameter and the minimum diameter, subtracting the difference between the maximum diameter and the minimum diameter from the average, and dividing the resulting value by the average. Generally spherical flavor delivery members preferably comprise a generally spherical outer shell.

[0035] The flavor delivery member can be manufactured according to any suitable method (e.g., by coextrusion molding), which will be understood by those skilled in the art.

[0036] Preferably, only a single flavor delivery member is embedded within the filter. However, additional flavor delivery members can be provided in the longitudinal axis direction of the filter. The additional flavor delivery members can be provided in the same filter segment or in additional filter segments. When additional flavor delivery members are provided within the filter, they can have the same or different attributes from each other.

[0037] The flavor delivery member can comprise any suitable combination of substances or materials, such as, for example, capsules for drug delivery, capsules encapsulating liquids, or those used in other encapsulating materials. As an example, flavor delivery members that are commonly used in the pharmaceutical industry can be used. Such flavor delivery members can be made of, for example, a gelatin-based material or a polymeric material such as modified cellulose. One type of modified cellulose that can be used is hydroxypropylmethylcellulose. In addition to or in both addition to gelatin and modified cellulose, the outer shell can contain polysaccharides.

[0038] A liquid flavorant can include any flavor compound or tobacco extract suitable for placement in a flavor delivery member in a liquid form to enhance the taste of the mainstream smoke generated during smoking of a smoking article that includes a filter. Suitable flavors or fragrances include, but are not limited to, menthol, mint (such as peppermint and Dutch mint), chocolate, licorice, citrus and other fruit flavors, gamma octalactone, vanillin, ethyl vanillin, anti - bad breath flavors, spice flavors (such as cinnamon), methyl salicylate, linalool, bergamot oil, geranium oil, lemon oil, ginger oil, and tobacco flavors. Other suitable flavors can include flavor compounds selected from the group including acids, alcohols, esters, aldehydes, ketones, pyrazines, combinations or mixtures thereof and the like.

[0039] (The filter material (of the filter segment or any additional filter element)) can comprise any suitable substance or material. Examples of suitable materials include, but are not limited to, cellulose acetate, cellulose, regenerated cellulose, polylactic acid, polyvinyl alcohol, nylon, polyhydroxybutyrate, polypropylene, paper, thermoplastics (such as starch), non - woven materials, and combinations thereof. One or more materials can be formed into an open cell structure. The filter material preferably includes cellulose acetate tow.

[0040] The filter can contain additional material either within the filter segment or within one or more additional elements incorporated into the filter. For example, the additional material can be incorporated into the fibrous filter tow of the filter segment or into an additional filter element. For example, the filter can contain absorbent material. The term "absorbent" means any substance that can function as an adsorbent, an absorbent, or both. The absorbent material can comprise activated carbon. The absorbent can be incorporated within a filter segment in which the flavor delivery member is embedded. However, it is more preferred that the absorbent be incorporated into an additional filter element upstream of the filter segment. Alternatively or additionally, the filter can contain an adhesive, a plasticizer, or a flavor release agent, or a combination thereof.

[0041] When absorbent material (such as activated carbon) is provided within the filter, i.e., within the filter segment in which the flavor delivery member is embedded or within an additional filter element, it is preferred that the flavor delivery member be downstream of the absorbent. With such an arrangement, the filter of the smoking article is effected by the absorbent, and the liquid flavorant is released into the filter without affecting the effectiveness of the liquid flavorant by absorption or adsorption by the absorbent.

[0042] The filter can contain a flavor release agent such as flavored cellulose yarn, sepiolite, a molecular sieve, or flavor-permeable activated carbon.

[0043] The filter can include one or more additional filter elements upstream of, downstream of, or both upstream and downstream of the filter segment. If the filter includes additional elements, the filter segment in which the flavor delivery member is embedded is only one of the filter components of the smoking article filter and not the entire smoking article filter. The additional filter elements can be arranged axially with the filter segment. For example, the filter can further include a plug or plugs or disk or disks of filter material downstream of the filter segment, a plug or plugs or disk or disks of filter material upstream of the filter segment, or plugs or disks of filter material both downstream and upstream of the filter segment. As another or additional alternative, the filter can further include a hollow tube or tubes downstream of the filter segment, a hollow tube or tubes upstream of the filter segment, or hollow tubes both downstream and upstream of the filter segment. If one or more hollow tubes are provided, the hollow tubes can have the same or different dimensions. As another or additional alternative, the filter can further include a void or indentation downstream of or upstream of, or both downstream and upstream of, the filter segment. Such voids or indentations can be defined by a filter wrapper surrounding the filter material. The voids or indentations can be empty or filled with any suitable substance.

[0044] A variety of filter configurations into which one or more flavor delivery members can be incorporated can be used. Exemplary filter structures that can be used include, but are not limited to, monofilters, dual filters, triple filters, single or multi-porous filters, recessed filters, free-flow filters, and combinations thereof. Monofilters typically include cellulose acetate tow or cellulose paper materials. Dual filters typically include a mouth-side end of cellulose acetate and segments of pure cellulose or cellulose acetate. The length and pressure drop of the segments within the dual filter can be adjusted to provide optimal adsorption while maintaining an acceptable RTD. The recessed filter includes at least two segments (e.g., acetate-acetate, acetate-paper, or paper-paper) separated by at least one recess. The recessed filter includes a recess open at the mouth-side end.

[0045] The filter can include at least a filter wrapper surrounding the filter material. The filter wrapper provides strength and structural rigidity for the filter, including the filter segments. When the filter includes one or more additional filter elements, the filter segments and the one or more additional filter elements are preferably wrapped from above with the filter wrapper. The filter wrapper can include any suitable material. The filter wrapper can prevent deformation outside the filter segments at the location where the flavor delivery member is embedded within the filter material. The filter wrapper can include a seam including one or more rows of adhesive. The seam preferably includes two rows of adhesive. One row of adhesive can include a hot melt adhesive. One row of adhesive can include polyvinyl alcohol.

[0046] The filter according to the present invention can be advantageously used for filter cigarettes and other smoking articles in which the tobacco material is burned to form smoke. Alternatively, the filter according to the present invention can be used in smoking articles in which the tobacco material is heated rather than burned to form an aerosol. The filter according to the present invention can also be used in smoking articles in which a nicotine-containing aerosol is generated from a tobacco material, a tobacco extract, or other nicotine source without combustion or heating.

[0047] According to a second aspect of the present invention, there is provided a smoking article comprising an aerosol-forming substrate and a filter according to the first aspect of the present invention. According to a second aspect of the present invention, there is provided a smoking article comprising a tobacco substrate and a filter according to the first aspect of the present invention. According to a second aspect of the present invention, there is also provided a smoking article comprising a tobacco rod and a filter according to the first aspect of the present invention.

[0048] In the case of a conventional cigarette, the aerosol-forming substrate can comprise a tobacco-containing portion, which is sometimes referred to as a tobacco rod or cigarette rod. Thus, a cigarette typically comprises two parts, a tobacco-containing portion and a filter. The tipping paper usually surrounds the filter and forms the mouth-end of the cigarette. The tipping paper overlaps the tobacco rod to hold the filter and the tobacco rod together. The tobacco rod usually comprises a paper wrapper in which the tobacco is wrapped, and an adhesive holds the seam of the paper wrapper together. The tobacco rod has a first end attached to the filter and a second end that is ignited or heated for smoking the tobacco. When the tobacco rod is ignited or heated for smoking, the smoke moves from the downstream ignited end through the tobacco rod to the filter end of the tobacco rod and further downstream through the filter.

[0049] Examples of suitable types of tobacco materials that can be used include, but are not limited to, fire-cured tobacco, Burley tobacco, Maryland tobacco, Oriental leaf tobacco, rare tobacco, specialty tobacco, mixtures thereof, and the like. The tobacco material can be provided in any suitable form including, but not limited to, tobacco lamina, processed tobacco material (such as volume expanded or puffed tobacco), processed tobacco stems (such as cut rolled or cut puffed stems), reconstituted tobacco material, mixtures thereof, and the like. Tobacco substitutes can also be used. In conventional cigarette manufacturing, the tobacco is typically used in the form of cut filler, i.e., pieces or strands cut to a width in the range of about 2.5 mm to about 1.2 mm or even to a width of about 0.6 mm. The length of the strands is in the range of about 6 mm to about 75 mm. Slim cigarettes (with a diameter of about 6.0 mm or less) do not require expanded tobacco. For slim cigarettes, it is preferred that less than about 20% of the total tobacco within the cigarette is expanded tobacco.

[0050] The packing density of the tobacco within the smoking article is preferably about 200 mg / cm -3 or more. The packing density of the tobacco of the smoking article is more preferably about 220 mg / cm -3 or more. The packing density of the tobacco of the smoking article is even more preferably about 240 mg / cm -3 or more. Slim cigarettes (with a diameter of about 6.0 mm or less) can tolerate a relatively high packing density or fill density of about 200 mg / cm -3 .

[0051] The smoking article preferably further comprises a tipping material attached to the tobacco rod or other aerosol-forming substrate and the filter. The tipping material provides additional strength and structural rigidity for the filter segment and can reduce the possibility of deformation of the outer surface of the filter segment at the location where the flavor delivery member is embedded within the filter material.

[0052] The tipping material may include a ventilation zone including perforations that penetrate the tipping material. The degree of ventilation is preferably greater than about 60%, more preferably greater than about 70%, and even more preferably greater than about 80%. The degree of ventilation is preferably less than about 95%, more preferably less than about 90%, and even more preferably less than about 85%. The degree of ventilation is preferably from about 60% to about 95%, more preferably from about 70% to about 90%, and even more preferably from about 80% to about 85%. Ventilation can reduce both the particulate phase components and the gas phase components of the mainstream smoke. However, the RTD level of a smoking article with a high level of ventilation may be too low to be considered acceptable to consumers. However, due to its relatively large cross-sectional area, adding a flavor delivery member embedded in the filter can result in a larger RTD, and the RTD level of the filter can be made desirable. When used with a high degree of ventilation, the flavor delivery member can increase the RTD, while reducing both the particulate phase components and the gas phase components of the mainstream smoke.

[0053] The tipping material may include at least one row of perforations to provide ventilation of the mainstream smoke. When the filter includes a filter wrapper, the perforations preferably extend through the filter wrapper. Alternatively, the filter wrapper may be permeable. The tipping material may be a standard pre-perforated tipping material. Alternatively, the tipping material may be perforated during the manufacturing process according to the desired number, size, and location of the perforations (e.g., using a laser). The number, size, and location of the perforations can be selected to provide the desired ventilation level. Together with the flavor delivery member and the filter material, ventilation results in a desirable RTD level. The RTD of the smoking article can be at least about 130 mm H2O before the liquid flavorant is released (e.g., before the flavor delivery member is crushed).

[0054] Preferably, a ventilation zone is provided upstream of the flavor delivery member. This is to reduce the possibility of liquid flavorant leaking from the perforations after the liquid flavorant is released. In one embodiment, the filter has a length of about 27 mm, the center of the flavor delivery member is located about 13.5 mm from the downstream end of the filter, and the row of perforations is provided at a position about 18 mm from the downstream end of the filter. In that case, if the filter segment is the only component of the filter, the row of perforations is located about 18 mm from the downstream end of the filter segment, or if the filter includes additional filter elements, the row of perforations is located about 18 mm from the downstream end of the filter, which may or may not be the downstream end of the filter segment. In one embodiment, the filter has a length of about 32 mm. The row of perforations can be provided at least about 11 mm from the downstream end of the filter.

[0055] In one embodiment, the smoking article further includes a tipping material for attaching the tobacco substrate and the filter, and the tipping material includes a ventilation zone including perforations extending through the tipping material, and the perforations are located upstream of the flavor delivery member.

[0056] The tipping material is preferably substantially impermeable to the liquid flavorant of the flavor delivery member. The low-permeability tipping material prevents the liquid flavorant from penetrating the tipping material and causing unsightly stains on the outside of the tipping material. Any suitable material can be used, including but not limited to, for example, cellophane and polyvinylidene chloride.

[0057] A third aspect of the present invention relates to the use of a flavor delivery member within a filter for a smoking article, wherein the filter is a filter segment comprising a filter material, the filter segment having a cross-sectional area measured perpendicular to the long axis of the filter, the flavor delivery member being embedded within the filter segment and surrounded on all sides by the filter material, the flavor delivery member comprising a structural material for containing a liquid flavorant for flavoring smoke during smoking, wherein the flavor delivery member releases at least a portion of the liquid flavorant when the filter is subjected to an external force, and the cross-sectional area of the flavor delivery member measured perpendicular to the long axis of the filter is at least about 30% of the cross-sectional area of the filter segment.

[0058] According to a fourth aspect of the present invention, there is provided a method of manufacturing a filter for a smoking article, the method comprising providing a continuous rod of filter material with a gap along the long axis of the rod, each flavor delivery member comprising a structural material containing a liquid flavorant, and the cross-sectional area of each flavor delivery member measured perpendicular to the long axis of the rod being about 30% of the cross-sectional area of the rod; and cutting the continuous rod of filter material at longitudinally spaced cuts to produce filter segments of filter material, each filter segment comprising a flavor delivery member embedded within the filter segment and surrounded on all sides by the filter material.

[0059] The method of the fourth aspect of the present invention is simple because the flavor delivery member is directly incorporated into the filter material. For example, the flavor delivery member can incorporate fibers of the filter material, which are bundled to form a filter material tow. No separate step for inserting the flavor delivery member is required.

[0060] Features described in connection with one aspect of the present invention may be applicable to another aspect of the present invention.

[0061] The present invention will be further described by way of illustration only with reference to the following accompanying drawings.

Brief Description of the Drawings

[0062]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0063] FIG. 1 is a perspective view of a smoking article 100 according to one embodiment of the present invention. The smoking article 100 includes a generally cylindrical tobacco rod 101 and a generally cylindrical filter 103. The tobacco rod 101 and the filter 103 are axially arranged in an end-to-end contact relationship and are preferably adjacent to each other. The tobacco rod includes an outer wrapper 105 surrounding the smoking material. The outer wrapper 105 can be a porous wrapping material or a paper wrapper. The tobacco is preferably shredded tobacco or tobacco cut filler. The tobacco rod 101 has an upstream ignition-side end 107 and a downstream end 109. The filter 103 has an upstream end 111 and a downstream mouth-side end 113. The upstream end 111 of the filter 103 is adjacent to the downstream end 109 of the tobacco rod 101. The filter material of the filter 103 is wrapped within a filter wrapper (not shown). Although not shown in FIG. 1, a flavor delivery member in capsule form is embedded in the filter 103.

[0064] Filter 103 is attached to tobacco rod 101 by tipping material 115 that surrounds the entire length of filter 103 and an adjacent region of tobacco rod 101. For clarity, tipping material 115 is shown in FIG. 1 in a state partially removed from the smoking article. Tipping material 115 is typically a paper-like product. However, any suitable material can be used. The tipping material preferably includes a material that is substantially impermeable to the liquid flavorant within the capsule. In this embodiment, tipping material 115 includes a circumferential row of perforations 117 aligned with filter 103. The perforations are provided for ventilation of the mainstream smoke and are located upstream of a capsule (not shown) embedded within filter 103.

[0065] As used herein, the relative positions of "upstream" and "downstream" between components of a smoking article are described in relation to the direction of the mainstream smoke when the mainstream smoke is drawn from tobacco rod 101 and through filter 103.

[0066] FIG. 2 is a cross-sectional view of filter 103 of FIG. 1 according to one embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2. In FIGS. 2 and 3, filter 103 includes filter segments 201 of filter material 203. Filter 103 further includes a flavor delivery member in the form of spherical capsules 205.

[0067] In the embodiment of FIGS. 2 and 3, capsules 205 are embedded within filter segments 201 and are surrounded on all sides by filter material 203. In this embodiment, the capsules comprise an outer shell and an inner core, the inner core containing a liquid flavorant. The liquid flavorant is for flavoring the smoke during smoking of the smoking article provided with the filter. Capsules 205 release at least a portion of the liquid flavorant when the filter is subjected to an external force, such as by compression by a consumer. In the embodiment shown in FIGS. 2 and 3, the capsules are generally spherical and have a substantially continuous outer shell containing the liquid flavorant.

[0068] As shown in FIG. 3, the capsule 205 has a diameter 301, and the filter segment 201 has a diameter 303 (inside the filter wrapper). Thus, the cross-sectional area of the capsule 205 measured in a direction perpendicular to the major axis direction of the filter is the annular region π(301) 2 It is. Similarly, the cross-sectional area of the filter segment 201 measured in a direction perpendicular to the major axis direction of the filter is the annular region π(303) 2 It is. Thus, the cross-sectional area of the capsule 205 as a percentage value of the cross-sectional area of the filter segment 201 is TIFF0007714604000001.tif1435.

Example

[0069] According to the first embodiment of the present invention, the diameter 301 of the capsule 205 is about 3.5 mm, the diameter 303 of the filter segment 201 inside the filter wrapper is about 6.41 mm, and the diameter of the filter segment 201 outside the filter wrapper is about 7.21 mm. The diameter of the cigarette wrapped with paper including the filter (sometimes called a slim cigarette) is about 7.35 mm. In this embodiment, the cross-sectional area of the capsule is about 30% of the cross-sectional area of the filter segment. In this embodiment, the length of the cigarette can be about 97 mm or about 83 mm. In this embodiment, the length of the filter can be about 27 mm or about 32 mm, and the length of the tipping paper can be about 32 mm or about 36 mm. The row of perforations in the circumferential direction can be provided at least about 11 mm from the mouth-side end, preferably about 18 mm, and the center of the capsule can be provided about 13.5 mm from the mouth-side end.

Example

[0070] According to a second embodiment of the present invention, the diameter 301 of the capsule 205 is about 3.5 mm, the diameter 303 of the filter segment 201 inside the filter wrapper is about 6.19 mm, and the diameter of the filter segment 201 outside the filter wrapper is about 6.99 mm. The diameter of the cigarette including the filter (sometimes called a slim cigarette) is about 7.10 mm. In this embodiment, the cross-sectional area of the capsule is about 32% of the cross-sectional area of the filter segment. In this embodiment, the length of the cigarette can be about 97 mm or about 83 mm. In this embodiment, the length of the filter can be about 27 mm or about 32 mm, and the length of the tipping paper can be about 32 mm or about 36 mm. The row of circumferential perforations can be provided at least about 11 mm from the mouth-end, preferably about 18 mm, and the center of the capsule can be provided about 13.5 mm from the mouth-end.

Example

[0071] According to a third embodiment of the present invention, the diameter 301 of the capsule 205 is about 3.5 mm, the diameter 303 of the filter segment 201 inside the filter wrapper is about 6.09 mm, and the diameter of the filter segment 201 outside the filter wrapper is about 6.89 mm. The diameter of the cigarette including the filter (sometimes called a slim cigarette) is about 7.00 mm. In this embodiment, the cross-sectional area of the capsule is about 33% of the cross-sectional area of the filter segment. In this embodiment, the length of the cigarette can be about 97 mm or about 83 mm. In this embodiment, the length of the filter can be about 27 mm or about 32 mm, and the length of the tipping paper can be about 32 mm or about 36 mm. The row of circumferential perforations can be provided at least about 11 mm from the mouth-end, preferably about 18 mm, and the center of the capsule can be provided about 13.5 mm from the mouth-end.

Example

[0072] According to a fourth embodiment of the present invention, the diameter 301 of the capsule 205 is about 3.2 mm, the diameter 303 of the filter segment 201 inside the filter wrapper is about 4.55 mm, and the diameter of the filter segment 201 outside the filter wrapper is about 5.35 mm. The diameter of the cigarette including the filter (sometimes called a super slim cigarette) is about 5.41 mm. In this embodiment, the cross-sectional area of the capsule is about 49% of the cross-sectional area of the filter segment. In this embodiment, the length of the cigarette can be about 97 mm or about 83 mm. In this embodiment, the length of the filter can be about 27 mm or about 32 mm, and the length of the tipping paper can be about 32 mm or about 36 mm. The row of circumferential perforations can be provided at least about 11 mm from the mouth-side end, preferably about 18 mm, and the center of the capsule can be provided about 13.5 mm from the mouth-side end.

Example

[0073] According to a fifth embodiment of the present invention, the diameter 301 of the capsule 205 is about 3.0 mm, the diameter 303 of the filter segment 201 inside the filter wrapper is about 3.84 mm, and the diameter of the filter segment 201 outside the filter wrapper is about 4.64 mm. The diameter of the cigarette including the filter (sometimes called a micro slim cigarette) is about 4.70 mm. In this embodiment, the cross-sectional area of the capsule is about 61% of the cross-sectional area of the filter segment. In this embodiment, the length of the cigarette can be about 97 mm or about 83 mm. In this embodiment, the length of the filter can be about 27 mm or about 32 mm, and the length of the tipping paper can be about 32 mm or about 36 mm. The row of circumferential perforations can be provided at least about 11 mm from the mouth-side end, preferably about 18 mm, and the center of the capsule can be provided about 13.5 mm from the mouth-side end.

Example

[0074] According to the sixth embodiment of the present invention, the diameter 301 of the capsule 205 is about 3.2 mm, the diameter 303 of the filter segment 201 inside the filter wrapper is about 3.84 mm, and the diameter of the filter segment 201 outside the filter wrapper is about 4.64 mm. The diameter of the cigarette including the filter (sometimes called a micro slim cigarette) is about 4.70 mm. In this embodiment, the cross-sectional area of the capsule is about 69% of the cross-sectional area of the filter segment. In this embodiment, the length of the cigarette can be about 97 mm or about 83 mm. In this embodiment, the length of the filter can be about 27 mm or about 32 mm, and the length of the tipping paper can be about 32 mm or about 36 mm. The row of circumferential perforations can be provided at least about 11 mm from the mouth end, preferably about 18 mm, and the center of the capsule can be provided about 13.5 mm from the mouth end.

Claims

1. A smoking article comprising: a tobacco substrate; and a filter, wherein the filter comprises a filter segment including a filter material, the filter segment having a cross-sectional area measured perpendicular to the major axis of the filter; and a flavor delivery member embedded in the filter segment and surrounded on all sides by the filter material, the flavor delivery member including a structural material encapsulating a liquid flavorant for flavoring smoke during smoking, the flavor delivery member configured to release at least a portion of the liquid flavorant when the filter is subjected to an external force; the cross-sectional area of the flavor delivery member measured perpendicular to the major axis of the filter is at least about 30% of the cross-sectional area of the filter segment; furthermore, the filter material of the filter segment comprises fibers having a denier per filament of from about 5.0 to about 12.0 and a total denier of from about 10,000 to about 35,000; the smoking article further comprises tipping material for attaching the tobacco substrate and the filter, the tipping material including a ventilation zone including perforations extending through the tipping material, the perforations being located at least 11 mm from the downstream end of the filter; A smoking article.

2. The smoking article according to claim 1, wherein the filter has a diameter of less than about 6.5 mm.

3. The smoking article according to any one of claims 1 to 2, wherein the cross-sectional area of the flavor delivery member measured perpendicular to the major axis of the filter is at least about 45% of the cross-sectional area of the filter segment.

4. The smoking article according to any one of claims 1 to 3, wherein the cross-sectional area of the flavor delivery member measured perpendicular to the major axis of the filter is at least about 55% of the cross-sectional area of the filter segment.

5. The smoking article according to any one of claims 1 to 4, wherein the flavor delivery member includes a capsule.

6. The smoking article according to claim 5, wherein the capsule has a burst strength of from about 5 N to about 24 N.

7. The smoking article according to any one of claims 1 to 6, wherein the filter material has a denier per filament of from about 5.0 to about 12.0 and comprises fibers having a total denier of from about 12,000 to about 30,000.

8. The cross-section of the filter segment and the flavor delivery member is circular, the diameter of the filter segment is from about 3.6 mm to about 6.5 mm, and the diameter of the flavor delivery member is from about 2.5 mm to about 4.5 mm. The smoking article according to any one of claims 1 to 7.

9. The cross-section of the filter segment and the flavor delivery member is circular, the diameter of the filter segment is from about 3.6 mm to about 5.5 mm, and the diameter of the flavor delivery member is from about 3.0 mm to about 3.5 mm. The smoking article according to any one of claims 1 to 8.

10. The cross-section of the filter segment and the flavor delivery member is circular, the diameter of the filter segment is from about 3.6 mm to about 4.5 mm, and the diameter of the flavor delivery member is from about 3.0 mm to about 3.5 mm. The smoking article according to claim 8.

11. The tobacco substrate is a tobacco rod. The smoking article according to any one of claims 1 to 10.

12. The tipping material is substantially impermeable to the liquid flavorant of the flavor delivery member. The smoking article according to any one of claims 1 to 11.

13. The RTD of the smoking article exceeds about 130 mm H 2 O before the liquid flavorant is released, the smoking article according to any one of claims 1 to 12.

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