GB2490728A

GB2490728A - Filter for a smoking article

Info

Publication number: GB2490728A
Application number: GB1108020.7A
Authority: GB
Inventors: David Morrison Russell; Wilbert Paulus Johanna Maria Schoenmakers; Paul Barry Farenden; Darren Seymour
Original assignee: British American Tobacco Investments Ltd; British American Tobacco Co Ltd
Current assignee: British American Tobacco Investments Ltd
Priority date: 2011-05-13
Filing date: 2011-05-13
Publication date: 2012-11-14
Also published as: GB201108020D0; WO2012156701A1

Abstract

A filter 20 for a smoking article comprises one or more additive release components 15 containing additive and a movable part 18 configured such that movements of the movable part releases additive. The movable part may be movable longitudinally and/or rotatably around the filter and may comprise a protrusion to engage the additive component. The additive release components may be located on the filter periphery between a covering layer and the filtration material. The additive release components may be located in one or more grooves extending longitudinally, circumferentially or helically. The filter may comprise an inner section and an outer annular section which is harder than the inner section (figure 7). Alternatively they may be located between two adjacent layers of covering layer such that on relative movement of the adjacent surfaces additive is released (figure 8). The covering layer may define a concertina section.

Description

A filter for a smoking article, a smoking article and a method of manufacture

Description

The present invention relates to a filter for a smoking article, a smoking article, and a method of forming a filter.

As used herein, the term "smoking article" includes smokeable products such as cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat-not-burn products (i.e. products in which flavour is generated from a smoking material by the application of heat without causing combustion of the material).

Typically, smoking articles are provided with filters removing constituents from the gaseous flow.

It is known to provide a frangible capsule containing a flavourant such as menthol inside the filter of a smoking article. By applying pressure to the outside of the filter, the smoker may break the capsule therein and release the flavourant. Thus, a smoker wishing to add flavour to the gaseous flow may do SO by simply squeezing the filter.

Individual breakable capsules having a flavourant therein and methods of manufacture thereof are known per se and are described in, for example, WO 2006/117697.

As the capsules are ruptured by application of a manual force directly by a user, the capsules may be difficult to rupture or may not reliably rupture.

The present invention provides, in a first aspect, a filter for a smoking article comprising: one or more additive release components containing additive; and a movable part configured such that movement of the movable part releases additive from at least one of the additive release components.

Thus, the additive release components can release the additive in a controlled manner.

Preferably, the one or more additive release component is configured such that movement of the movable part actuates progressive release of additive.

Preferably, the movable part is a release member movable around an exterior of the filter to engage with the additive release component(s).

The present invention further provides a filter for a smoking article comprising:one or more additive release component conntining additive; and a covering layer defining two adjacent surfaces, wherein the additive release components are located between the adjacent surfaces such that on relative movement of the adjacent surfaces of the covering layer, additive is released from at least one of the additive release components.

The present invention provides, in a second aspect, a smoking article comprising: a source of smokable material connected to a filter comprising: one or more additive release components containing additive; and a movable part configured such that movement of the movable part releases additive from at least one of the additive release components.

The present invention provides, in a third aspect, a method of manufacturing a filter for a smoking article, comprising: providing one or more additive release component cont2ining additive; and providing a movable part configured such that movement of the movable part releases additive from at least one of the additive release components.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a cut-away perspective view of a first embodiment of the present invention; Figure 2 shows a perspective view of the first embodiment of the present invention in a first state; Figure 3 shows a perspective view of the first embodiment of the present invention in a second state; Figure 4 shows a cut-away side elevation view of the first embodiment of the present invention in the second state; Figure 5a shows a perspective view of a filter according to a second embodiment of the present invention; Figure 5b shows a perspective view of a filter of a third embodiment of the present invention; Figure 6 shows a perspective view of a filter of a fourth embodiment of the present invention; Figure 7 shows a perspective view of a filter of a fifth embodiment of the present invention; Figure 8 shows a partial axial cross-sectional view of a smoking article of a sixth embodiment of the present invention; Figure 9 shows a partial axial cross-sectional view of a smoking article of a io seventh embodiment of the present invention; Figure 10 shows a partial axial cross-sectional view of a smoking article of an eighth embodiment of the present invention; Figures 11 a and 11 b show cut-away side elevation views of a filter of a ninth embodiment of the present invention, in a first and second state respectively; Figure 12 shows schematically a method of manufacturing a smoking article according to the present invention; and Figures 13a, 13b, 13c show perspective views of a tenth embodiment of the present invention.

Figure 1 shows a smoking article 10 according to a first embodiment of the present invention. The smoking article 10 comprises a source of smokable material, which is preferably tobacco, in the form of a cylindrical tobacco rod 11. A filter 20 is co-axially attached to the tobacco rod 11. The filter 20 preferably comprises a plurality of co-axial filter sections, described in further detail below.

A first filter section 12 comprises filtration material surrounded by a porous sheet material, which is preferably plug wrap. The porous sheet material is permeable to liquids and to gaseous flow. The filtration material is preferably cellulose acetate tow, as is conventionally known. The filtration material is preferably homogenous.

The term "homogenous" is used to mean that the filtration material is substantially uniform throughout the first filter section 12, and in particular, is uniform in a radial direction through the first filter section 12.

The filter 20 comprises one or more additive release components 15. Preferably, a plurality of additive release components 15 are arranged on a periphery of the first io filter section 12. The additive release components 15 preferably each contain an additive in the form of a fluid, preferably, a liquid. The additive release components are preferably capsules. The additive release components may be microcapsules, preferably having a diameter of less than 1mm, and optionally, less than 0.5mm. The additive release components may be ruptured or broken by compression, which releases the additive. The additive in the additive release components 15 may be a flavourant, for example menthol, or may be water.

Each additive release component 15 comprises an outer wall, which is preferably made of gelatine, and an inner space filled with the fluid additive. The additive release components 15 lie against or adjacent to an exterior surface of the first filter section 12. The additive release components 15 may be located within the porous sheet (plugwrap) surrounding the filtration material. The filtration material secures the additive release components 15 in position. Alternatively, the additive release components 15 may be located on or adjacent an exterior surface of the porous sheet (plugwrap) surrounding the filtration material. The additive release components may be held in place by an adhesive, such that the additive release components are located securely and uniformly along the exterior surface of the first filter section. Alternatively, the additive release components 15 are constrained within the filter 20 adjacent to the first filter section 12, but not affixed to the first filter section 12. The additive release components 15 are secured in place by a covering layer 16, described below, surrounding the first filter section 12. The additive release components 15 may be attached to an interior of the covering layer 16 by an adhesive, or may be constrained within the covering layer 16 without an adhesive.

The additive release components 15 extend over a part or the whole circumference of the first filter section 12. The additive release components 15 may be partially or fully embedded in an exterior surface of the first filter section 12, or embedded within the filtration material adjacent the periphery.

The filter 20 preferably further comprises a second filter section 13. The second filter section 13 is at a rearward (mouthpiece) end of the filter 20, and co-axially aligned with the first filter section 12. The second filter section 13 preferably comprises a filtration material, which may be wrapped in a porous sheet material, e.g. plugwrap. The second filter section 13 preferably does not comprise any additive release components. The filtration material is preferably cellulose acetate tow, as is conventionally known. The filtration material is preferably homogenous.

The term "homogenous" is used to mean that the filtration material is substantially uniform throughout the second filter section 13, and in particular, is uniform in a radial direction through the second filter section 13.

The filter 20 optionally includes a third filter section 14 adjacent to the tobacco rod 11, at a longitudinally forward end of the filter 20. The third filter section 14 is arranged coaxially with, and longitudinally forward of, the first filter section 12.

The third filter section preferably comprises a filtration material, which may be wrapped in a porous sheet material, e.g. plugwrap. The third filter section preferably does not comprise any additive release components. The filtration material is preferably cellulose acetate tow, as is conventionally known. The filtration material is preferably homogenous. The term "homogenous" is used to mean that the filtration material is substantially uniform throughout the third filter section 14, and in particular, is uniform in a radial direction through the third filter section 14.

The smoking article is described above as having two or three separate filter sections, which are held together in a fixed and abutting arrangement. The smoking article may alternatively comprise a single filter section, comprising additive release components 15. The additive release components 15 may he located only in a part of the filter spaced from a rear\vard end, and/or spaced from a forward end of the filter. Alternatively, the first and second filter sections, and if present, the third filter section, may be integrally formed. The smoking article may not comprise a separate third filter section. The additive release components 15 in the first filter section may be longitudinally spaced from the tobacco rod, or some may be located adjacent the tobacco rod.

Preferably, an exterior diameter of the first filter section 12 is less than an exterior Jo diameter of the second filter section 13. In addition, an exterior diameter of the first filter section 12 is less than an exterior diameter of the third filter section (if present) or tobacco rod. Preferably, the exterior diameters of the second and third filter sections are substantially the same.

References to the first, second or third filter sections refer to filtration material \vrapped in the porous sheet material. Preferably, only a curved exterior surface is wrapped by the sheet material, as is conventionally known. The first, second, and (if present) third filter sections may be directly connected together, or may be held together by a covering layer 1 6 extending around the first, second or (if present) third filter sections.

The covering layer 16 forms the exterior surface of the filter 20. The covering layer is a sheet material wrapped around the first, second and (if present) third filter sections. The covering layer 16 is preferably impermeable to the additive, at least in an area around the additive release components. The covering layer is preferably formed of a material, e.g. a paper, which is substantially impermeable to hquids and gaseous flow. The paper may be coated to be impermeable to liquids. The covering layer may connect the filter 20 to the tobacco rod 11, and may be formed of tipping paper. Alternatively, the covering layer does not connect the filter 20 to the tobacco rod 11, and a separate wrapped sheet of material provides a connection.

The covering layer comprises 1 6 may be at least partially transparent. The covering layer 16 may be transparent over the first filter section 12 allowing viewing of the additive release components 15. The covering layer 16 is preferably transparent over the whole circumference, or may be transparent over only a part of the circumference. The covering layer 16 is preferably opaque over the second filter section, and if present, the third filter section. The covering layer 16 is preferably a single covering layer sheet, which may be wrapped as a single unit. The covering layer sheet may connect the first, second and third filter sections together.

Alternatively, the covering layer may be separate sections, which are not directly affixed together.

The covering layer extends at a substantially constant diameter around the first, second and third filter sections 12, 13,14. The covering layer 16 is affixed to an exterior surface of the second filter section and is affixed to an exterior surface of the third filter section. The first covering layer section 1 6 is radially spaced apart from the first filter section 12, since the first filter section 12 has a smaller diameter than the second and third filter sections. A chamber 17, \vhich is preferably an annular chamber, is defined between the covering layer 1 6 and the first filter section 12, and bounded longitudinally by the second and third filter sections 13, 14. The chamber 17 preferably extends around the whole periphery of the first filter section.

The additive release components 15 are located in the chamber 17. Preferably, the additive release components 15 and chamber 17 are dimensioned such that only a single radial layer of additive release components 1 5 are located in the chamber surrounding the first filter section 12. Thus, a radially outwardly part of the additive release components 15 is close to, and underlying, an interior surface of the covering layer 16. The additive release components 15 are therefore adjacent to an exterior surface of the filter 20. The radial extent of the chamber is the difference in radius between the first and second filter sections.

The chamber 17 may be between 0.2mm and 0.8mm deep in a radial direction, and between 10 and 16mm in a longitudinal direction. For example, a kingsize smoking article having a diameter of approximately 7mm to 8mm may have a chamber which has a depth of 0.5mm and a length of 13mm. A superslim smoking article having a diameter of approximately 5mm to 6mm may have a chamber which has a depth of 0.75mm and a length of 13mm. The capsules may have a size selected such that a plurality of capsules can flow like a fluid.

The smoking article 10 comprises a moveable part configured to move to release additive from the additive release components. The moveable part is the release member 18. The release member 18 may be a tubular member extending around the whole circumference of the filter 20, as illustrated, or alternatively may be a member extending around only a part of the circumference of the filter 20. In particular, the release member 18 may be a C-shaped clip. The release member 18 extends around the exterior surface of the covering layer 16, and is slidable around the first filter section 12 comprising the additive release components 15. The release member 18 is preferably formed of a sheet material, formed to curve around the first filter section. The release member 18 is configured to exert a radially inward force on the first filter section 12.

The release member 1 8 is configured to rupture the additive release components I S by sliding longitudinally around an exterior surface of the filter 20. The additive release components 15 are broken by compression against a reaction surface. The first filter section 12 provides the reaction surface against which the additive release components 15 can be compressed. The additive released can enter the adjacent filtration material of first filter section 12.

Alternatively, the additive release components may be located, and optionally affixed, on an exterior surface of the covering layer. Alternatively, the additive release components may he affixed to an interior surface of the release member.

The additive release components are initially covered by a part of the release member (but not initially crushed by the release member), such that the additive release components are not exposed. When the additive release components are on an exterior of the covering layer, the covering layer is permeable to the additive, such that the additive can enter the filtration material.

Figure 2 shows a perspective view of the smoking article 10, in an initial state. The release member 18 is located longitudinally of the additive release components IS, and is preferably location forwardly of the additive release components 15. The additive release components 15 are in an initial state, in which none of the additive release components 15 have been ruptured.

In addition, the release member 18 comprises one or more engaging elements 19.

The engaging elements 19 are protrusions, extending radially inwardly, and preferably extending around substantially the whole circumference of the release member 18. The engaging elements 19 are integrally formed with the release member 18, preferably as a corrugation or deformation of the sheet material of the release member 18. The engaging elements 19 are configured to apply pressure to the additive release components 15. Preferably, the release member 18 substantially only applies pressure to the covering layer 16 around the first filter section 12 through the engaging elements. The release member 18 may only contact the covering layer 1 6 at the engaging elements.

The engaging elements 19 are configured to exert a radially inward force on the additive release components 15. As the release member 18 is moved longitudinally along the first filter section 12, the engaging elements 19 consecutively rupture the additive release components 15.

Alternatively, the release member 18 may not comprise any engaging elements. The release member 18 may have a constant interior radius which is configured to engage with additive release components 15. The release member 18 may optionally comprise raised features on an exterior surface to facilitate gripping of the release member by a user.

Figure 3 shows a perspective view of the smoking article 10, in an activated state.

The release member 18 has been slid rearwardly around the first filter section 12.

The release member 18 has ruptured the additive release components 15 over which the release member 18 has travelled, by compressing the additive release components 15 against the reaction surface provided by the first filter section 12.

The covering layer is deformable to allow compression of additive release components within the covering layer.

Figure 4 shows a cut-away side elevation view of the filter 20 in the activated state, in which some of the additive release components 15 have been ruptured by the release member 18. The intact additive release components I 5a are a first colour, which is visible through the partially transparent first covering layer section 16. The additive release components I 5a still contain the additive. The filter 20 also comprises additive release components lSb which have been ruptured. The fluid from the additive release components 15b has been released and may enter the first filter section 12, and/or second and third filter sections 13,14. The ruptured additive release components 15b are a second colour, different from the first colour of the intact additive release components ISa. The additive fluid releasable from the additive release components 15 is preferably coloured, and the outer shell of the additive release components 15 is substantially transparent Thus, the intact and ruptured additive release components 15a,15b appear different in colour. The transparent first covering layer section 16 provides a visual invitation to a user of the number and location of ruptured and intact capsules I Sa,1 Sb. The release member 18 may also be transparent, such that the user can view the additive release components 15 through the release member 18.

The release member 18 is configured to compress the covering 16 over the additive release components 15. Tn particular, the release member 18 deforms the covering layer 16 radially inwardly over the chamber, compressing the additive release components 15 located in the chamber against the reaction surface, preferably provided by the first filter section 12.

It will be appreciated that the release member 18 is configured to rupture the additive release components 15 and thereby to provide a reliable and constant force on the additive release components 15, which in turn provides reliable rupturing of the additive release components 15. Furthermore, the user releases additive by movement of the release member 18, instead of directly rupturing the additive release components 15. Therefore, the user is not required to directly compress the additive release components 15.

In addition, the filter 20 preferably comprises a plurality of additive release components 15 spaced longitudinally. The user has manual control over the release member 18, and so can select the range over which the release member 18 is moved.

By selection of a longitudinal distance to move the release member 18, a user may select the number of additive release components 15 to rupture, providing an incremental control of the additive released The amount of additive released can be varied substantially continuously or in small increments. The amount of additive released can be selected by control of the movement of the release member.

Movement of the release member actuates progressive release of the additive.

Preferably, additive is released from all additive release components within an area swept by movement of the release member.

It is known to provide a smoking article with a single large capsule, two or three large capsules or a cluster of micro-capsules. Single large capsules provide one-shot release of additive. Two or three large capsules provide a coarse control over -12 -delivery of additive, having large increments between release levels (e.g. zero, low, medium and high doses for three capsules). Clusters of microcapsules are typically arranged for simultaneous crushing and release of additive. Microcapsules provide a possibility of delivering doses of additives in many incremental levels, but they are difficult to manipulate individually. The filter preferably comprises a plurality of additive release components, wherein at least some of the plurahty of additive release components are sequentially engaged by the movable part. At least some of the additive release components are arranged over a longitudinal and/or rotational extent, to be sequentially engaged by longitudinal or rotational movement of the movable part. The combination of a slider and microcapsules in the present invention gives variable delivery in small increments over a range, combined with ease of manipulation.

The first, second and third filter sections 12, 13, 14 are preferably formed as separate sections of filtration material wrapped in a porous sheet material. The first, second and third filter sections 12, 13, 14 are abutting and coaxially aligned in a longitudinal relationship. The first, second and third filter sections are preferably not directly connected to each other, and connected only by the covering layer 16.

Each filter section is formed as a solid cylinder of filtration material.

Figure Sa shows a filter 40 comprising a first filter section 42. The first filter section 42 is preferably an alternative embodiment of the first filter section 12 described above, and is configured as part of a smoking article as described, which is also part of the present invention. All features are as described above, unless specified as different. Alternatively, the first filter section 42 may comprise the only filter section in a smoking article. The filter 40 comprises a moveable part configured to move to release additive from the additive release components. The moveable part is the release member 49, configured to slide longitudinally substantially as described with respect to Figures 1 to 4.

The first filter section 42 comprises one or more grooves 47 in or adjacent an exterior surface. A plurality of additive release components 45 is located in the or each groove 47. The grooves 47 extend longitudinally, and preferably, parallel to a longitudinal axis of the first filter section 42. Preferably, the first filter section 42 comprises a plurality of grooves 47, for example, four grooves, equally spaced around the circumference of the first filter section 42. The grooves 47 are preferably defined by an exterior surface of the sheet material surrounding the filtration material. The sheet material and filtration material are both shaped to define the grooves. The grooves 47 are covered by the covering layer 46, which forms a cylindrical tube around the first filter section 42. The additive release components 45 are located in the grooves 47, and covered by the covering layer 46.The additive release components 45 are therefore constrained in the grooves between the porous sheet material surrounding the filtration material, and the covering layer 46.

Preferably, the grooves 47 are dimensioned for a single row of additive release components, or alternatively, each groove may comprise a plurality of rows of additive release components.

The release member 48 comprises a movable tubular sleeve or C-shaped member, as described above. The release member 48 comprises one or more engaging elements 49. The engaging elements 49 are protrusions at one or more circumferential positions, extending radially inwardly and aligned with the or each groove 47. Each groove 47 is engaged by a separate engaging element 49. The engaging elements 49 are integrally formed with the release member 48, preferably as a corrugation or deformation of the sheet material of the release member 48. The engaging elements 49 are configured to apply pressure to the additive release components 45 in the grooves 47. Preferably, the release member 48 substantially only applies pressure to the covering layer 46 around the first filter section 42 through the engaging elements 49 at the location of the grooves 47. The release member 48 may only contact the covering layer 46 at the engaging elements.

The engaging elements 49 are configured to exert a radially inward force on the additive release components 45 in the grooves 47, through the covering layer. As the release member 48 is moved longitudinally along the first filter section 42, the -14-engaging elements 49 consecutively rupture the additive release components 45 in the grooves 47.

Alternatively, the release member 48 may not comprise any engaging elements. The release member 48 may have a constant interior radius \vhich is configured to engage with additive release components 45 in the grooves 47. The additive release components 45 extend radially beyond the grooves and exterior surface of the first filter section 42, such that the additive release components 45 in the grooves 47 can he contacted and compressed by the release member.

Alternatively, the release member 48 may comprise only one engaging element, configured to be located in a plurality of grooves 47. The release member 48 may be rotatable to engage a selected groove 47. Longitudinal movement of the release member 48 within the selected groove 47 ruptures additive release components 45 in that groove 47, but does not rupture additive release components 45 in the other grooves 47. A different groove 47 may be selected by rotation of the release member 48.

Figure Sb shows a filter 50 comprising a first filter section 52, configured for use with a movable part in the form of a release member (not shown). The first filter section 52 is preferably an alternative embodiment of the first filter section 42 described above, and is configured as part of a smoking article as described, which is also part of the present invention. All features are as described above, unless specified as different.

The filter 50 comprises additive release components 35 arranged in one or more grooves 57, substantially as described with reference to Figure 5a. The additive release components are preferably covered by a covering layer (not shown). In filter 50, the additive release components 53 are connected together by a web 53. The web 53 connects a plurality of additive release components 55 in an elongate length of spaced additive release components. The web 53 allows improved handling and placement of the additive release components 55 in the grooves.

The web 53 may comprise a thread connecting the additive release components 55.

The thread is a flexible elongate member. The thread may extend through the additive release components 55, and inserted whilst the additive release components are being formed. The formed additive release components have the thread secured extending therethrough. In particular, the additive release components may be formed by co-extrusion, with the outer fluid forming an outer shell around an inner fluid of additive. The thread is located through the outer shell when in a fluid form, such that the thread is secured within the outer shell when the outer shell solidifies.

The thread may be formed according to W02010/003899, which is incorporated herein by reference Alternatively, the web may comprise a tube of a porous sheet material, in which the additive release components are affixed. The web may be formed according to W02010/003899, which is incorporated herein by reference. In particular, the additive release components are affixed within the tube of porous sheet material, e.g. plugwrap, preferably by ultrasonic spot welding, which preferably also forms pockets in the tube contnining the additive release components.

In a further embodiment of the invention (not shown), one or more additive release components may be located within the filtration material of the first filter section.

The one or more additive release components are offset from a longitudinally extending centre-line of the first filter section. Thus, the additive release components are radially closer to one part of a side exterior surface of the first filter section than another part. The additive release components are preferably adjacent the exterior surface of the first filter section, or may spaced from the exterior surface and surrounded by filtration material. The one or more additive release components are configured to release contained additive when engaged by a release member, as described in any other embodiment.

Figure 6 shows a filter 60 comprising a first filter section 62, configured for use with a movable part in the form of a release member (not shown). The first filter section 62 is preferably an alternative embodiment of the first filter section 42 described above, and is configured as part of a smoking article as described, which is also part of the present invention. All features are as described above, unless specified as different.

The first filter section 62 comprises one or more grooves 67 in which additive release components 65 are located. The one or more grooves 67 extend helically around a periphery and length of the first filter section 62. Preferably, the filter 60 comprises only one helical groove 67 containing additive release components 65.

The groove 67 and additive release components 65 are otherwise formed as described with respect to Figure 5a. The additive release components are preferably covered by a covering layer (not shown).

The ifiter 60 is configured for use with a release member (not shown), preferably with an engaging element, substantially as described with respect to Figure 5a. The release member is configured to rotate when moving longitudinally, as the engaging element tracks the helical groove 67.

Figure 7 shows a filter 70 comprising a first filter section 72, configured for use with a moveable part in the form of a release member (not shown). The first filter section 72 is preferably an alternative embodiment of the first filter section 42 described above, and is configured as part of a smoking article as described, which is also part of the present invention. All features are as described above, unless specified as different. Alternatively, the first filter section 72 may comprise the only fitter section in a smoking article.

The filter 70 comprises one or more grooves 77 containing a plurality of additive release components 75. The grooves 77 may extend longitudinally as described with respect to Figure 5a, or helically as described with respect to Figure 6. The additive release components are preferably covered by a covering layer (not shown). The features of the grooves and additive release components are as described in any embodiment above.

The first filter section 72 comprises two portions, an outer portion 72a and an inner portion 72b. The outer portion 72a is an annular cylinder of filtration material, co-co-axially surrounding the inner portion 72b of filtration material. The outer portion 72a is preferably harder than the inner portion 72b. The increased hardness provides an improved reaction surface against which the additive release components 75 can be compressed. The groove 77 may extend radially through the outer portion 72a only, may extend radially up to the exterior surface of the inner portion 72b, or may extend into the inner portion 72b.

Preferably, the outer portion 72a and inner portion 72b are primarily formed of the same filtration material, preferably cellulose acetate tow. The outer portion 72a is provided with additional additives, or an additional quantity of additive, compared to the inner portion 72b. In particular, the higher hardness of the outer portion 72a is preferably achieved by using a higher proportion of plasticiser than in the inner portion 72b. Alternatively or in addition, the porous sheet material around the outer portion 72a may be relatively hard. For example, the sheet material may be relatively thick. The sheet material may be paper, having an area density of greater than 40g/m2, greater than 60 g/m2, greater than 80 g/m2, or greater than 100 g/m2.

Alternatively or in addition, the paper may be treated with an additive to be more rigid, for example, starch, an adhesive or shellac.

The harder outer portion 72a provides a harder reaction surface against which the additive release components 75 can be compressed. The harder first filter section therefore provides for improved rupturing of the additive release components 75.

Preferably, the amount of plasticiser is increased by more than: 10%,20%, 30%, 40%, 50%, 60, 70%, 80%, 90%, or 100% compared to the inner portion 72b.The hardness of the filtration material may be measured on the "Filtrona" scale. A standard hardness of filtration material on the Filtrona scale is 80-89%. The inner portion 72b may have such a hardness of less than 90%, and in particular, 80 to 89%, on the Filtrona scale. The outer portion 72a preferably has a hardness of greater than 90% on the Filtrona scale. Preferably, the hardness of the outer portion 72a is greater than 95%, and optionally greater than or approximately 96%.

The first filter section is not a homogenous filter section in this embodiment.

Alternatively, the first filter section may have a uniform hardness throughout (i.e. homogenous), and not have separate inner and outer portions. The type and hardness of the filtration material of the whole filtration section may be the same as described for the outer portion 72a. The second filter section and, if present, third fiRer section, may have a type and hardness of the filtration material as described for the inner portion 72b.

The Filtrona hardness is determined as follows: a filter rod (for example a length of 102 millimetres) having a mean diameter (D), of about 7.8 millimetres, is compressed between two plates provided in the testing instrument. The rod is subjected to compression for 15 seconds by a load of 300 grams applied to opposite sides of the cylindrical surface of the rod and the average depression (A), that is the decrease in diameter of the rod is measured. The hardness is the diameter of the sample measured at a load of 300 grams and expressed as a percentage of the original diameter, that is, it is given by the following formula: Hardness %[-A)]/Dx100 Figure 8 shows a further embodiment of smoking article 80. The smoking artide 80 comprises a first filter section 82 attached to a source of smokable material, in particular, a tobacco rod 81. The smoking article 80 further comprises a second filter section 83, located co-axially and rearwardly of the first filter section 82. The second filter section 83 is movable longitudinally relative to the first filter section 82.

A chamber 84 is defined between the first and second filter sections 82,83. The length of the chamber 84 is variable as the second filter section 83 moves relative to the first filter section 82. Preferably, the length of the chamber 84 is variable from zero length, in which the first and second filter sections 82,83 are abutting, to a pre-determined maximum length.

A covering layer 86 extends around the first and second filter sections 82,83. The covering layer 86 connects the first and second filter sections 82,83, and extends around the chamber 84 to define an exterior surface of the chamber 84. The covering layer 86 optionally also connects the first filter section 82 to the tobacco rod 81. The covering layer 86 may comprise one or more layers of sheet material, preferably, paper. The covering layer 86 is preferably formed of an air impermeable material, and preferably defines one or more ventilation apertures. The covering layer is preferably tipping paper.

The second filter section 83 and attached movable parts of covering layer 86 define a movable part configured to move to release additive from the additive release components.

The covering layer 86 is configured to allow the second filter section 83 to move longitudinally relative to the first filter section 82. The covering layer 86 is also configured to release an additive, for example, flavourant, when the second filter section 83 is moved apart from the first filter section 82.

The covering layer 86 is folded on itself to form a folded section 86a. The folded section 86a is a tubular section of the covering layer 86 which is folded in an annular loop, and defined by two adjacent layers of sheet material. The exterior of the two adjacent layers of sheet material is configured to slide over the interior of the two layers to reduce the extent of the folded section 86a, and increase the longitudinal length of the chamber 84 and separation of the first and section filter sections 82,83. Preferably, the folded section 86a extends radially outwardly from a position over the chamber 84. The folded section 86a is folded forwardly over an exterior of the first filter section 82.

The folded section 86a defines an annular cavity 87. A plurality of additive release components 85 are located in the cavity 87. The additive release components 85 are preferably capsules, and more preferably microcapsules, for example substantially as described in any embodiment. The additive release components 85 are configured to release additive when the second filter section 83 is slid rearwardly, apart from the first filter section 82. The additive release components 85 are preferably affixed to one, and more preferably both, of the two layers of sheet material defining the cavity 87. The additive release components 85 may be affixed with adhesive. The relative movement between the exterior layer and interior layer exerts a force on the -20 -additive release components 85 \vhich causes rupture of the additive release components 85 and release of the additive. The additive is preferably released through the open end of the folded section 86a into the chamber 84, and potentially then into the first and/or second filter sections 82,83.

Figure 9 shows a further embodiment of smoking article 90. The smoking article 90 comprises a first filter section 92 attached to a source of smokable material, in particular, a tobacco rod 91. The smoking article 90 further comprises a second filter section 93, located co-axially and rearwardly of the first filter section 92. The second filter section 93 is movable longitudinally relative to the first filter section 92. A chamber may be selectively defined between the first and second filter sections 92,93. The length of the chamber is variable as the second filter section 93 moves relative to the first filter section 92. Preferably, the length of the chamber is variable from zero (as sho\vn), where the filter sections 92,93 abut, to a second pre-determined maximum length. In particular, the first and/or second filter section may comprise a spigot of filtration material, being a section of reduced diameter, and extending within a folded section 96a. Alternatively, the length of the chamber is variable from a first pre-determined length, which is non-zero, to a second pre-determined maximum length, such that the filter sections 92,93 are always separated.

A covering layer 96 extends around the first and second filter sections 92,93. The covering layer 96 connects the first and second filter sections 92,93, and extends around the chamber to define an exterior surface of the chamber 94. The covering layer 96 optionally also connects the first filter section 92 to the tobacco rod 91.

The covering layer 96 is one or more layers of sheet material, preferably, paper. The covering layer 96 is preferably formed of an air impermeable material, and preferably defines one or more ventilation apertures. The covering layer is preferably tipping paper.

The covering layer 96 is configured to allow the second filter section 93 to move longitudinally relative to the first filter section 92. The covering layer 96 is also -21 -configured to release an additive, for example, fiavourant, when the second filter section 93 is moved apart from the first filter section 92.

The covering layer 96 is folded on itself to form a folded section 96a. The folded section 96a is a tubular section of the covering layer 96 which is folded in an annular loop, and defined by two adjacent layers of sheet material. The interior of the two adjacent layers of sheet material is configured to slide over the exterior of the two layers to reduce the extent of the folded section 96a, and increase the longitudinal length of the chamber and separation of the first and section filter sections 92,93. Preferably, the folded section 96a extends radially inwardly from a position around the chamber 84. The folded section 96a extends within the chamber 94, and preferably extends parallel and adjacent to an interior of the covering layer 96 defining an exterior of the chamber 94.

The folded section 96a defines an annular cavity 97. A plurality of additive release components 95 are located in the cavity 97. The additive release components 95 are preferably capsules, and more preferably microcapsules, for example substantially as described in any embodiment. The additive release components 95 are configured to release additive when the second filter section 93 is slid rearwardly, apart from the first filter section 92. The additive release components 95 are preferably affixed to one, and more preferably both, of the two layers of sheet material defining the cavity 97. The additive release components 95 may be affixed with adhesive. The relative movement between the exterior layer and interior layer exerts a force on the additive release components 95 which causes rupture of the additive release components 95 and release of the additive. The additive is preferably released through the open end of the folded section 96a into the chamber 94, and potentially then into the first and/or second filter sections 92,93.

A release member 98 is affixed to an exterior of the covering layer 96. The release member 98 is preferably affixed around the second filter section 93. The release member 98 provides a grip for a user to move the second filter section 93 longitudinally apart from the first filter section 92. The release member 98 may be -22 -attached to the covering layer 96 rear\vardly of the the folded section 96a, and extend forwardly to overlie the folded section 96a.

The second filter section 93, release member 98 and attached movable parts of covering layer 96 define a movable part configured to move to release additive from the additive release components.

Figure 10 shows a further embodiment of smoking article 100. The smoking article too comprises a first filter section 102 attached to a source of smokable material, in particular, a tobacco rod 101. The smoking article tOO further comprises a second filter section 103, located co-axially and rearwardly of the first filter section 102.

The second filter section 103 is movable longitudinally relative to the first filter section 102. A chamber 104 is defined between the first and second filter sections 102,103. The length of the chamber 104 is variable as the second filter section 103 moves relative to the first filter section 102. Preferably, the length of the chamber 104 is variable from 2ero, where the filter sections 102,103 abut, to a second pre-determined maximum length. In particular, the first and/or second filter section may comprise a spigot of filtration material, being a section of reduced diameter, and extending within the concertina section 108. Alternatively, the length of the chamber 104 is variable from a first pre-determined length, which is non-2ero, to a second pre-determined maximum length, such that the filter sections 102,103 are always separated. A covering layer 106 extends around the first and second filter sections 102,103. The covering layer 106 connects the first and second filter sections 102,103, and extends around the chamber 104 to define an exterior surface of the chamber 104. The covering layer 106 optionally also connects the first filter section 102 to the tobacco rod 101. The covering layer 106 is one or more layers of sheet material, preferably, paper. The covering layer 106 is preferably formed of an air impermeable material, and preferably defines one or more ventilation apertures.

The covering layer is preferably tipping paper.

The covering layer 106 is configured to allow the second filter section 103 to move longitudinally relative to the first filter section 102. The covering layer 106 is also configured to release an additive, for example, fiavourant, when the second filter section 103 is moved apart from the first filter section 102.

The covering layer 106 is folded to form a concertina section 108. The concertina section 108 is a tubular section of the covering layer 106 surrounding the chamber 104. The concertina section 108 can fold as a concertina in order to vary the length of the chamber 104. The concertina section 108 has a plurality of segments 108a of varying diameter, defined by fold lines formed around the circumference of the concertina section 108 at lines of maximum and minimum diameter.

In a retracted state, the first and second filter sections 102,103 are relatively close, such that the concertina section 108 is compressed. The segments 108a of the concertina section 108 increase in angle, and the segments are orientated towards a plane perpendicular to the longitudinal axis of the smoking article. The chamber 104 has a relatively short length.

In an extended state, the first and second filter sections 102,103 are urged apart, such that the segments 108a of the concertina section 108 decrease in angle, and the segments are orientated towards a plane parallel to the longitudinal axis of the smoking article. The chamber 104 has a relatively long length. The concertina section 108 allows the chamber 104 to vary in length without requiring parts sliding relative to each other.

A plurality of additive release components 105 are located in the concertina section 108. The additive release components 105 are preferably capsules, and more preferably microcapsules, for example substantially as described in any embodiment.

The additive release components 105 are configured to rupture and release additive when the second filter section 103 is moved rearwardly, apart from the first filter section 102. The additive release components 105 are preferably affixed to the interior surfaces of two adjacent segments 108a of the concertina section 108. The additive release components 105 may be affixed with adhesive. The relative movement between the segments 108a exerts a force on the additive release components 105 which causes rupture of the additive release components 105 and release of the additive. In particular, separation of the segments 108a pulls apart the additive release components. Alternatively, the expansion of the concertina section may urge the additive release components 105 against an exterior of the first and/or second filter section, which provides a reaction surface against which the additive release components 105 are compressed. The additive is preferably released into the chamber 104, and/or into the first and/or second filter sections 102,103.

The second filter section 103 and concertina section 108 defines a movable part configured to move to release additive from the additive release components.

Figures 1 Ia and I lb show half-cross-sections of a filter according to the present invention in use. The filter may be as described in any one of Figures 1 to 7, and equivalent terms indicate equivalent features. Features not described as different are substantially as described with respect to any one of Figures I to 7.

A first filter section 112 comprises a movable part in the form of a release member 118. The release member 118 is configured to move longitudinally to engage with and rupture additive release components 115 arranged on a periphery of the first filter section 112. The additive release components 115 may be in a groove or other recess having a reduced diameter relative to a forward section or rearward section 113, which may be a second filter section.

The additive release components 115 are preferably covered by a covering layer (not shown). Alternatively, the additive release components 115 may be affixed to an exterior surface of a covering layer (not shown).

In Figure 1 la, the release member has engaged and ruptured two additive release components 115, being the most forward of the longitudinally spaced additive release components 115. In Figure 1 Ib, the release member 118 has been moved further rearwardly, to cover and rupture all of the additive release components 115.

Figure 12 illustrates a method of manufacturing a filter according to the present invention, as described with respect to Figures 1 to 7 and Figures 11 a and II b. A sheet material is provided (step 121) for forming the release member. The sheet material is preferably a cellulose acetate film, and is preferably a cast cellulose acetate film. The material of the release member is formed into a C-shape (step 122). The forming may be by extrusion of granules of cellulose acetate, which is extruded into a film. The formed C-shape is an elongate section, for forming release members for a plurality of filters. The elongate C-shape section is cut laterally (step 123) to form a release member for only one filter. Separately, a filter rod is formed (step 124), comprising a first filter section with additive release components, and optionally, a second and third filter section. The C-shape release member is clipped around the first filter section (step 125).

The release member of any embodiment may be formed by moulding, extrusion and cutting or wrapping a section of coated paper (e.g. coated tipping paper). In particular, the release member may be made of cellulose acetate, and formed by moulding or extrusion.

Figures iSa to 13c show views of a further embodiment of filter during manufacture. The filter is related to the filter described in any one of Figures 1 to 7, and equivalent terms indicate equivalent features. Features not described as different may be substantially as described with respect to any one of Figures 1 to 7.

The filter 130 comprises a first filter section 132, second filter section 133 and third filter section 134, substantially as described above. One or more of the first, second and/or third filter section may be integrally formed. The first filter section 132 has a periphery comprising a plurality of additive release components 135 extending in an array longitudinally and circumferentially. The additive release components 135 preferably extend around the whole circumference of the first filter section 132. The additive release components 135 may extend from an exterior surface of the first filter section 132, or may be covered by a sheet material adjacent the exterior surface of the first filter section 132. The additive release components 135 may be attached to a substrate which is wrapped around the first filter section. -26 -

The filter 130 comprises a movable part configured to move to release additive from the additive release components 135. The movable part comprises a release member 138. The release member 138 is configured to rotate around a periphery of the first filter section 132 to rupture the additive release components. In particular, the release member 138 comprises one or more engaging elements 139. Each engaging element 139 is a protrusion, extending radially. The engaging element 139 is integrally formed with the release member 138, preferably as a corrugation or deformation of the sheet material of the release member 138. The engaging element 139 is configured to apply pressure to the additive release components 135 on rotation. Preferably, the release member 138 substantially only applies pressure through the engaging element 139. The engaging element 139 may he a longitudinally extending protrusion, having the same or greater longitudinal extent than the longitudinal extent of the additive release components 135, and may extend the whole length of the release member. The engaging element 139 may be configured to apply pressure to rupture additive release components when rotated around an exterior of the smoking article. The provision of more than one engaging element 139 provides for simultaneous engagement of additive release components at different circumferential positions. All of the additive release components may be engaged by a rotation by a pre-determined amount, which may be a full rotation (360 degrees), or may be less (e.g. 120 degrees). The additive release components may be located on a periphery of the first filter section at a uniform radial location, or may be located at varying radial locations, e.g. in one or more grooves.

The engaging element 1 39 is configured to exert a radially inward force on the additive release components. As the release member 138 is moved circumferentially around the first filter section 132 by rotation, the engaging elements 139 consecutively ruptures the additive release components.

Figure 13a shows the release member 138 during formation as a strip of sheet io material. The sheet material is preferably cellulose acetate. The strip of sheet material is curled around the first filter section in Figure 13b, and fully formed in Figure 13c. Rotation of the release member 138 will cause engaging element 139 to engage the additive release components 135 and release additive. -27 -

The first filter section 132 preferably has a uniform external diameter, on which the additive release components 135 are located. Alternatively, the first filter section 132 may comprise one or more circumferentially extending grooves in which the additive release components 135 are located. The engaging element is configured to engage in the grooves, substantially as described for longitudinally extending grooves in Figure Sa.

The material of the release member has been described as cellulose acetate film, which may be used for any embodiment. Alternatively, the release member of any embodiment may be formed from a sheet material selected from any one of the following options, in any combination. The sheet material may be paper, having an area density of greater than 40 g/m2, greater than 60 g/m2, greater than 80 g/m2, or greater than 100 g/m2. The paper may be treated with an additive to be more rigid, for example, starch, an adhesive or shellac. The sheet material may he a cast cellulose acetate film, for example, the film known as CLARIFOIL manufactured by Deutsche-Benkert. The film may have a thickness of approximately, or greater than, 20km, 50pm or 100pm. Preferably, the film has a thickness of between 20 and 50pm. The sheet material may be a cellulose acetate film formed from cellulose acetate tow. The tow is treated with at least one of steam, heat and pressure, and fed through an aperture. The cellulose acetate is optionally further rolled to form a film, which may have a thickness as mentioned above. The sheet material may be a cellulose film. Alternatively, the film may be made from polylactic acid (PLA). The thickness of the film may be as above. This film may be transparent. The sheet material may be a laminate of any two sheet materials. In particular, the sheet material may be a laminate of paper and cellulose acetate film (formed by either method). The sheet materials may be affixed together with an adhesive, or may only he co-located without being affixed together. Alternatively, the sheet material may be metal.

The smoking article of any embodiment may be configured to have variable ventilation. In particular, the movable part may he configured to move to vary -28 -ventilation, in addition to causing release of additive. For the embodiments of Figures 1 to 7, ha and hib, and 13a to 13c the slidable or rotatable release member may be configured to selectively cover or uncover ventilation apertures in the covering layer around the first, second and/or third filter sections which allow ventilation air into filtration material of the respective filter section. The movable part may optionally be provided with ventilation apertures alignable with ventilation apertures in the coveting layer. For the embodiments of Figures 8 and 9, the folded sections may be configured to selectively covet or uncover ventilation apertures in the coveting layer around the first, second and/or third filter sections or chamber which allow ventilation air into filtration material of the respective filter section or chamber. For the embodiment of Figure 1 0, the concertina section may be provided with ventilation apertures which allow ventilation dependent on the extension of the smoking article.

The diameter of the filter of any embodiment is within the range 4 to 10 mm.

The capsule diameter is preferably within the range (J.1 -3.5 mm, and more preferably 0.5 to 1.2 mm. Preferably, the capsule diameter is 0.8mm to 1.2mm, or approximately 1mm. Alternatively, the capsule diameter may be less than lmm.Alternatively, the additive release component diameter may be less than 1mm, or less than 0.7mm, or less than 0.5mm, or less than 0.3mm.

These ranges are not, however, intended to he limiting and the skilled person would understand that larger or smaller filter diameters or capsules could be employed.

In a further embodiment, the additive release components may be located within a movable section of covering layer, forming an exterior of the filter. The additive release components may be attached to an interior surface of the movable section, and to a surface underneath, such that lifting of the movable io section ruptures the additive release components to release additive. Preferably, the movable section lifts in a circumferential direction, i.e. is pulled by a user laterally to the longitudinal axis. One or more movable sections may provide for further control over release of additive. Alternatively, a sheet material (e.g. paper) may be provided with additive release components, preferably micro-capsules, and rolled to form the filter or a section of the filter. The rolled paper may surround a filter, or may form the whole cross-section of a filter section.

Alternatively, the filter may comprise a sleeve which is moveable longitudinal or rotationally relative to the filter within. The sleeve may extend longitudinally beyond the filtration material, and/or may have a length which covers the majority of the filtration material, all of the length of the filtration material, or is longer than the filtration material. The additive release components, preferably micro-capsules may be arranged in longitudinally extending strips. The movement of the sleeve is configured to release additive from the additive release components located on or adjacent an interior surface of the sleeve.

A filter may be formed so as to have more than one type of additive. For example, the additive release components may be formed so that one or more additive release components in a filter contain a first additive, and one or more additive release components in the filter contain a different, second, additive.

As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product The additive release components may be capsules having an outer shell, containing additive fluid (liquid or powder) in an interior cavity. The outer shell of each additive release component is frangible to release all of the additive on application of pressure.

The filter may comprise a reaction surface against which the additive release component can be urged, in order to facilitate release of additive. In particular, the additive release components may be located on a periphery of the filter. The radially adjacent filtration material may provide a reaction surface against which the additive release component can be urged. Preferably, the filtration material may be relatively hard (e.g. by containing an increased amount of plasticiser) to form the reaction surface, and may have a hardness on the Filtrona scale of more than 90%. The additive release components may be located within the filtration material, or may be located in a cavity adjacent to the filtration material. The cavity may be formed by an elongate inner rod of filtration material, which one or two annular outer sections of filtration material surround. A covering layer forming an exterior of the filter is attached to one or both of the outer sections of filtration material, and spaced from the inner rod to define a cavity.

Preferably, the inner rod is harder than the annular outer sections, optionally by containing more plasticiser.

Alternatively, each additive release component may release its additive contents in a plurality of discrete doses, preferably actuated by a plurality of separate applications of pressure. This type of additive release component may comprise a resiliently or plastically deformable outer shell, preferably configured to release additive through a slit formed in a pre-determined area. Alternatively, this type of additive release components may comprise a porous absorbent substrate having an open cell structure (e.g. open cell foam), in which the additive is contained. The substrate may be at least partially resiliently deformable. The substrate is surrounded by an outer shell to retain the additive, which may be frangible, resiliently deformable, plastically deformable, or a thin coating. The substrate may form discrete additive release components, or may be in the form of an annulus in the first filter section. Alternatively, this type of additive release component may comprise a porous matrix containing the additive in discrete cavities and having a dosed cell structure (e.g. dosed cell foam), which is plastically deformable to release the additive.

The additive release components may be individually attached to the filter or substrate. Alternatively, the additive release components may be connected by a web, and may be connected between laminated strips of sheet material.

Alternatively, the strips of sheet material may form the additive release -31 -components, such that the additive release components do not have a separate outer shell, and the strips of sheet material contain the additive.

The additive release components have been described as spherical. Alternatively, the additive release components may be elongate, with a longitudinal axis extending parallel to a longitudinal axis of the filter. The elongate additive release component preferably has a circular or elliptical cross-section, and contain more additive than an additive release component of the same diameter. The elongate additive release component preferably has a maximum lateral extent of less than 3.5mm, or less than 3mm, or from 2mm to 3mm. Alternatively, or in addition, the elongate additive release component may have a radial cross-sectional area which is less than 5Q% of the radial cross-sectional area of the smoking article, and optionally, less than 4()% or less than 3Q%. Such an additive release component is optimised for use in a small diameter smoking article, e.g. having a diameter of 5mm to 6mm, or 6mm to 7mm.

The additive release components have been described as individually located in the smoking article. Alternatively, a plurality of the additive release components may be surrounded by an outer wall or outer encapsulation. The outer encapsulation may be porous or configured to rupture or deform to allow release of additive on compression. The outer encapsulation may itself be contained within a further encapsulation. The additive may he contained within a plurality of discrete cavities within an open cell substrate, or a closed cell substrate. The open cell substrate, and optionally the closed cell substrate, have an outer encapsulation. One or more additive release components may be affixed to an exterior of a substantially larger additive release component. Alternatively, a plurality of additive release components, of the same or different si2es, may be affixed together. Any of these embodiments may be considered as a plurality of components connected in a unitary structure.

The additive released from the additive release components has been described as being entrained by ventilating air and/or gaseous flow from the tobacco rod.

Alternatively, flow containing additive may be selectively released from the filter.

The filter comprises a selecting means, preferably in the form of a movable element, preferably rotatable, at a mouthpiece end of the filter. The selecting means, least a part of which is movable in relation to the first and second flow paths, is configured to select a first flow path, a second flow path, or optionally, an adjustable proportion of the first and second flow paths. The first flow path may correspond to an annular, radially outer flow path, and the second flow path may correspond to a radially inner flow path within the first flow path. Alternatively, first and second half-cylindrical filter parts respectively define the first and second flow paths, the first and second filter parts arranged together to form a cylindrical filter part. The additive may be initially encapsulated within one or more additive release components (i.e. capsules), prior to being selectively released.

The additive release components have been described as formed of gelatine, other types may be used in combination with a filter of the present invention.

The additive release components may be manufactured by a known co-extrusion process, for an additive release component size of 500p.m to 10 mm. In the co-extrusion process, two fluids may be extruded together so that an additive release component is created by surface tension.

The shell fluid may be a warm gelatin solution, and liquid contents, e.g. menthol, are respectively delivered under pressure from separate tanks into a two-fluid nozzle. The shell fluid and liquid contents flow from a nozzle where they form droplets in a carrier fluid, the droplets having an outer shell of shell fluid and an inner core of liquid contents. A cooling mechanism is provided to cool and solidify the shell fluid. Alternatively, the shell material may be alginate, agar-agar, gum arabicum, latices or waxes.

Alternatively, the additive release components may be formed by any suitable process for encapsulating a liquid. For example, the additive release components may be formed by interfacial polymerisation, which may produce an additive release component size of 0.2i.tm to a few miffimetres. The shell may be made of -33 -a polymer, for example, polyester, polyamide, polyurea, polyurethane, or a biodegradable polymer e.g. protein, polysaccharides or oligo saccharides.

Alternatively, the additive release components may he formed by complex coacervation, which may produce a particle size of lOim to a few millimetres.

The additive release component may be made from gelatine and gum arabic.

Alternatively, the additive release components may be formed by single extrusion, which may produce a particle size of 200 pm to a few millimetres. The additive release component shell may be made from alginate, chitosan, carrageenan, cellulose derivatives, or waxes.

Alternatively, the additive release components may he formed by melt extrusion, which may produce a particle size of 300vm to a few millimetres. The additive release component shell may be made from gelatine, sugars, maltodextrins, corn syrup, food polymers or modified starches.

Alternatively, the additive release components may be formed by melt injection, which may produce a particle size of 200 Im to a few millimetres. The additive release component shell may he made from carbohrate materials, e.g. sucrose, glucose syrups and modified starches.

Alternatively, the additive release components may he formed by a spray drying microencapsulation process, which may produce a particle size of l0pm to a few millimetres. The additive release component shell may be made from polys accharide s (starch, alginate, agar, pectin, carrageenan, gums), proteins (gelatine, casein), fats and fatty acids, cellulose derivatives, lipids (waxes, shellac, carnuba or beeswax).

io Any materials for the additive release components or filter must be safe to use, and are subject to regulatory approval. Embodiments of the invention may he configured to comply with applicable laws and/or regulations, such as, by way of non- -34-limiting example, regulations relating to flavours, additives, emissions, constituents, and/or the like. For example, the invention may he configured such that a smoking article implementing the invention is compliant with applicable regulations before and after manipulation or release of an additive by a user. In some embodiments, the implementation is such that a smoking article meets or exceeds required regulatory test(s) in all user-configurable positions, such as, by way of non-limiting example, the testing threshold(s)/ceiling(s) for cigarette emissions and/or smoke constituents.

Any of the features described in any embodiment may he used in combination with any other features of any other embodiment.

Claims

-35 -Claims 1. A filter for a smoking article comprising: one or more additive release component containing additive; and a movable part configured such that movement of the movable part releases additive from at least one of the additive release components.
2. The filter as claimed in claim I wherein one or more additive release component is configured such that movement of the movable part actuates progressive release of additive.
3. The filter as claimed in claim I or 2 wherein the movable part is a release member movable around an exterior of the filter to engage with the additive release component(s).
4. The filter as claimed in any one of the preceding claims wherein the filter comprises a plurality of additive release components, wherein at least some of the plurality of additive release components are sequentially engaged by the movable part.
5. The filter as claimed in any one of the preceding claims wherein the movable part is a release member movable longitudinally and/or rotatably around the filter to release additive from the additive release components.
6. The filter as claimed in any one of the preceding claims wherein the additive release components are located on or adjacent a periphery of the filter.
7. The filter as claimed in any one of the preceding claims wherein the additive release components are located in one or more grooves.

-36 -
8. The filter as claimed in claim 7 wherein the one or more grooves extend longitudinally, or, the one or more grooves extend helically, or, the one or more grooves extend circumferentially.
9. The filter as claimed in any one of the preceding claims wherein movable part comprises at least one engaging element comprising a protrusion configured to engage the additive release components.tO. The filter as claimed in claim 7 or 8, and claim 9, wherein the at least one engaging element is engaged in one or more of the grooves.11. The filter as claimed in any one of the preceding claims wherein the movable part is a sleeve extending wholly or partially around the filter.12. The filter as claimed in any one of any one of the preceding claims wherein the movable part is configured to compress the additive release components against a reaction surface, and preferably, the reaction surface is formed or supported by filtration material.13. The filter as claimed in any one of the preceding claims wherein the additive release components are located at or adjacent a periphery of filtration material of the filter, wherein the additive release components are within a wrap surrounding the filtration material, or wherein the additive release components are outside a wrap surrounding the filtration material.14. The filter as claimed in any one of the preceding claims wherein the filter comprises an inner section of filtration material, and an annular outer section of filtration material surrounding the inner section, wherein the outer section is harder than the inner section.-37 - 15. The filter as claimed in claim 14 wherein the outer section comprises a higher proportion of plasticiser than the inner section.16. The filter as claimed in any one of the preceding claims, further comprising: a covering layer forming an exterior surface of the filter, and a first filter section comprising filtration material, wherein the covering layer is spaced from the first filter section such that a chamber is defined bet\veen the covering layer and the first filter section, wherein the additive release components are located in the chamber.17. The filter as claimed in claim 16, wherein the covering layer extends with a substantially constant diameter around the first filter section, and further extends around a second filter section and/or a third filter section, wherein the covering layer is affixed to an exterior surface of the second filter section, and/or third filter section.18. The filter as claimed in claim 16, wherein the covering layer extends over one or more grooves in an external surface of the first filter section, such that the additive release components are retained within the or more grooves by the covering layer.19. The filter as claimed in any one of the preceding claims wherein the plurality of additive release components are connected by a web.20. The filter as claimed in claim I wherein the movable part comprises a covering layer defining t\vo adjacent surfaces, wherein the additive release components are located between the adjacent surfaces such that on relative movement of the adjacent surfaces of the covering layer, additive is released from at least one of the additive release components.21. The filter as claimed in claim 20 wherein the additive release components are affixed to the two adjacent surfaces of the covering layer.-38 - 22. The filter as claimed in claim 20 or 21 wherein the adjacent surfaces of the covering layer define a cavity in \vhich the additive release components are located.23. The filter as claimed in claim 22 wherein the cavity is defined by a section of covering layer folded to overlie an adjacent section of covering layer, and preferably, the folded section is radially outwardly of the adjacent covering layer, or the folded section is radially inwardly of the covering layer.24. The filter as claimed in claim 21 or 22 wherein the covering layer defines a concertina section, and the adjacent surfaces of the covering layer are adjacent segments of the concertina section.25. The filter as claimed in any one of claims 20 to 24 wherein the movable part further comprises a second filter section movable longitudinally relative to a first filter section, wherein a chamber is defined between the first filter section and second filter section.26. The filter as claimed in claim 25 wherein the additive release components are configured to release additive at least partially.: into the chamber.27. The filter as claimed in any one of claims 20 to 26 \vherein the movable part further comprises a release member providing a grip to move a part of the filter relative to another part of the filter, and preferably, to move a second filter section relative to a first filter section.28. The filter as claimed in any one of the preceding claims wherein the movable part is configured to additionally control a ventilation of the filter.Jo 29. The filter as claimed in any one of the preceding claims wherein the additive release components are attached to an interior surface of the movable part.-39 - 30. The filter as claimed in any one of the preceding claims, wherein the additive release components have an average diameter of between 0.5mm and 1.5mm, and optionally, less than 1mm, and optionally, less than 0.5mm.31. A filter for a smoking article comprising: one or more additive release component containing additive; and a covering layer defining two adjacent surfaces, wherein the additive release components are located between the adjacent surfaces such that on relative movement of the adjacent surfaces of the covering layer, additive is released from at least one of the additive release components.32. The filter as claimed in claim 31 wherein the adjacent surfaces of the covering layer define a cavity in which the additive release components are located.33. The filter as claimed in claim 32 wherein the cavity is defined by a section of covering layer folded to overlie an adjacent section of covering layer, and preferably, the folded section is radially outwardly of the adjacent covering layer, or the folded section is radially inwardly of the covering layer.34. The filter as claimed in claim 31 or 32 wherein the covering layer defines a concertina section, and the adjacent surfaces of the covering layer are adjacent segments of the concertina section.35. A smoking article comprising: a source of smokable material connected to a filter as claimed in any one of the preceding claims.36. A method of manufacturing a filter for a smoking article, comprising: providing one or more additive release component containing additive; and providing a movable part configured such that movement of the movable part releases additive from at least one of the additive release components.37. The method of claim 36 further comprising: forming a movable part comprising a release member movable around an exterior of the filter from a sheet material, and preferably, forming the release member by extrusion, moulding or wrapping.38. The method of claim 36 or 37 wherein the material of the movable part is cellulose acetate, cellulose or polylactic acid.39. The method of claim 36, 37 or 38 further comprising: forming the release member as a planar strip of sheet material, and wrapping the strip of sheet material around the first filter section to form a tubular sleeve or C-shaped clip.40. A filter as hereinbefore described with reference to and as shown in the accompanying drawings.