EP2879531A2

EP2879531A2 - Smoking article with menthol filter

Info

Publication number: EP2879531A2
Application number: EP13734117.8A
Authority: EP
Inventors: Diego Ferrazzin; Alessandro BEGHIN; Daniele SANNA; Mario Antonio FRANCESE
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2012-08-02
Filing date: 2013-07-05
Publication date: 2015-06-10
Anticipated expiration: 2033-07-05
Also published as: BR112015002025A2; JP6535782B2; BR112015002025B1; KR20150037997A; JP2015523091A; WO2014019804A2; EP2879531B1; JP6378677B2; KR102183809B1; JP2018138032A; AR091954A1; WO2014019804A3; RU2636564C2; RU2015106914A; CN104540403A; CN104540403B

Abstract

The present invention relates to a smoking article, comprising a filter, the filter comprising: a plug of filter material having a longitudinally extending surface; a wrapper wrapped around the longitudinally extending surface of the plug; and a menthol patch realized on an inner surface of said wrapper facing said longitudinally extending surface of said plug, wherein the menthol patch is applied to the wrapper and the plug is attached to the wrapper by means of the menthol patch before the wrapper is closed around the filter material.

Description

Smoking Article with Menthol Filter

The present invention relates to a smoking article with a filter and a method for the production of such a filter.

Filter cigarettes typically comprise a rod of tobacco cut filler surrounded by a paper wrapper and a cylindrical filter aligned in an end-to- end relationship with the tobacco rod, with the filter attached to the tobacco rod by tipping paper. In conventional filter cigarettes, the filter may consist of a plug of cellulose acetate tow wrapped in porous plug wrap. To adhere the filter material within the filter, the filter material is adhered to the porous plug wrap. Filter cigarettes with multi-component filters that comprise two or more segments for the removal of particulate and gaseous components of the mainstream smoke are also known.

To enhance the flavour of the mainstream smoke, it is known to provide smoking articles with flavourants, in the filter. Passive flavour release mechanisms are known wherein the flavour is released without any action of the consumer. For example, the international patent application WO-A-2009/080604 describes a filter for a smoking article such as a cigarette. The article includes a plug of filter material and a wrapping held by stripes of adhesive to the periphery of the filter material. The adhesive contains a flavourant which may be naturally coloured such as to provide a pattern around the perimeter of the end face of the filter.

The British patent application GB-A-2229078 discloses a process for making a cigarette filter which includes applying a flavour on one or more of the faces of the wrapping material which contacts the filter material .

Also, active flavour release mechanisms are known wherein the consumer activates the flavour release. For example, it is known to introduce a capsule filled with flavourant into the filter. The capsule can be broken by a consumer when additional flavour is desired.

It would be desirable to provide means for releasing flavour within a filter for a smoking article that, in use, provide improved flavour enhancement, and, in particular, improved menthol flavour delivery, to a consumer. It would be particularly desirable to provide such a filter using standard filter making apparatus and techniques.

According to the invention, there is provided a smoking article comprising a filter, wherein the filter is comprising : a plug of filter material having a longitudinally extending surface; a wrapper wrapped around the longitudinally extending surface of the plug; and a menthol patch. The menthol patch is realized on an inner surface of the wrapper facing the longitudinally extending surface of the plug . According to the invention, the menthol patch is applied to the wrapper and the plug is attached to the wrapper by means of the menthol patch before the wrapper is closed around the filter material.

The smoking article can be a conventional smoking article including a tobacco rod, for example coupled to the filter via a tipping paper, or a non-conventional smoking article, such as a smoking article to be used in conjunction with a system for electronic smoking.

The term "filter" is used throughout the specification to indicate a section of the smoking article that is configured to remove at least partially gas phase or particulate phase smoke constituents or both gas phase and particulate phase smoke constituents from the mainstream smoke drawn through the filter. The filter of the invention may include one filter segment, or a plurality of filter segments. Each segment of the filter may have a different longitudinal length. The filter segments are abutting in the longitudinal direction. Where two or more segments are provided, the filter segments may be of the same construction and materials as each other but more preferably, the individual segments have a different construction, or contain different filtration material or additives. Where two or more segments are present in the filter, at least one of the segments is adapted to remove at least partially gas phase or particulate phase smoke constituents or both gas phase and particulate phase smoke constituents from the mainstream smoke drawn through the filter. One or more of the remaining segments of the filter according to the invention also may not contribute to the removal of smoke constituents but instead may have different functions as for example influencing the flavour of the mainstream smoke or changing the ventilation of the smoking article

Moreover, an additional element, in the following called "filter inserted object", can be comprised in the filter or in a segment of the filter. This object may be either including flavourant to modify the sensory attributes of the cigarette, or it may alter some other characteristics of the smoke, such as ventilation and resistance to draw. Objects present in the filter are for example one or more rupturable capsules containing flavourant, flavour pellets, flavoured or non-flavoured strands, exchange resin beads, absorbent/adsorbent particles, restrictors and combinations thereof. A single object is preferably comprised in a single segment of the filter of the invention, however in some specific cases, such as for example when beads are considered, hundreds of objects may be included .

The wrapper may comprise porous plug wrap, impermeable plastics or any other suitable material known in the art. In the wrapper, an inner surface and an outer surface are defined. The inner surface is the surface mainly facing the one or more plugs when the smoking article is assembled, while the outer surface is generally the surface mainly either in contact with the exterior of the filter or covered by additional one or more wrapping layers depending on the filter construction. Within the wrapper, also a "seam area" can be identified, where the wrapper overlaps itself in order to be closed around the plug forming a longitudinal seam. The overlapping area, which includes a portion of the inner surface and of the outer surface of the wrapper, is referred to as seam area where the outer surface and the inner surface of the wrapper are bonded one on the other. The remaining area, that is, the area of the inner surface not part of the seam area, is referred to as "inner rod surface". The inner rod surface is generally in direct contact to the plug rod circumferentially surrounding the plug .

The term "flavourant" is herein used to indicate a substance, compound or a mixture of substances capable of triggering a sensation involving the taste of a person. Preferably, the sensation involves gustatory and olfactory sensations. In other words, such a flavourant is recognizable by a person skilled in the art as being able to impart, enhance or modify in a desired manner the flavour or the taste of an article or composition to which it is added .

Possible flavourants are preferably flavourants for tobacco products, and include for example tobacco, peppermint, coffee, menthol, spearmint or cognac. The flavourant is preferably in liquid, foam or gel state, or solid, transformable into liquid at a certain temperature.

The flavourant may additionally include one or more additives, for example heat stabilizers, emulsion stabilizers, additives to give adequate processing properties, colorants or any combination thereof.

As known in the art, the wrapper is to be attached to the plug, for example by gluing the wrapper on the plug, in order to form the filter. It is preferred that the attachment is strong enough to withstand the stress exerted on the filter during the use of the smoking article, such that the detachment of the wrapper from the plug is prevented .

For this purpose, the filter of the invention includes, on the inner surface of the wrapper facing the longitudinally extending surface of the plug, a menthol patch.

A patch in the present context indicates a layer of material which covers an area of the inner surface of the wrapper. Preferably, it covers an area of the inner rod surface. The shape of the patch is arbitrary and may include a square, a stripe, a rectangle, a wavy line, a triangle or a combination of these or other geometries. The patch may cover most of the inner rod surface of the wrapper or just a small fraction of the inner rod surface of the wrapper. Moreover, the patch may extend along the whole longitudinal length of the wrapper, or only for a portion of the longitudinal length of the wrapper. The patch has a thickness which is sufficient to allow for a secure connection between the plug and the wrapper. Moreover the layer's thickness may be homogeneous or non- homogeneous. A layer of between about 2 micrometres and about 50 micrometres is preferred .

The term "Menthol" is used throughout the specification to refer to the substance that is applied to products to induce a menthol flavour. Preferably, a commercially available menthol as used herein comprises at least 90 percent of 2-isopropyl-5-methylcyclohexanol of chemical formula CioH₂oO. However, it is to be understood, that commercially available menthol will typically comprise additional additives, stabilizers and thickeners which are known to the person skilled in the art for the use within and outside of the tobacco industry. Such a commercially available menthol is for example the one distributed by Fuerst Day Lawson Ltd, from London (UK) .

Further, the term 2-isopropyl-5-methylcyclohexanol refers to all the 8 stereoisomers of 2-isopropyl-5-methylcyclohexanol, even if the term menthol usually comprises mostly the ( 1R,2S,5R) stereoisomer. However, the ( 1R,2S,5R) stereoisomer is preferred, as it is the most stable stereoisomer of 2-isopropyl-5-methylcyclohexanol .

It has been found, that menthol has adhesive properties, which means that it is capable of adhering or bonding elements together, such as the wrapper to the plug in the present case. The fact that the menthol itself has adhesive properties does not mean that it includes adhesive, the adhesive properties are intrinsic properties of the menthol used in the filter of the invention and are due to the chemical and physical structure of the menthol . Therefore, the menthol patch in a single element combines flavourant properties and adhesive properties, due to the intrinsic characteristics of the menthol.

Advantageously, due to the double functionality of the invention to use the menthol patch as flavourant and to adhere the plug to the inner rod surface of the wrapper, the filter of the invention requires a reduced number of processing steps for its fabrication compared to a flavoured filter according to the prior art. The application of a menthol patch on the wrapper, wherein the menthol acts not only as a flavourant but also as an adhesive gluing the wrapper onto the plug, reduces or eliminates the need of additional adhesive deposition on the wrapper. The steps of flavouring the filter with menthol and depositing the adhesive on the wrapper are therefore at least partially merged.

Preferably, the menthol patch comprises at least 99% of 2- isopropyl-5-methylcyclohexanol. In other words, the menthol patch comprises substantially pure menthol. As said, the presence of menthol alone is enough to allow a good adherence between the wrapper and the plug .

For a further enhancement of the flavour, according to a preferred embodiment of the invention, the filter may include an additional filter inserted object as above defined including flavourant. The flavourant contained in this object can be identical to or different from the menthol used in the patch, allowing a variety of flavours' combinations. More preferably, the flavouring inserted object comprises at least one capsule. The use of a menthol patch allows the simple and advantageous combination of a plurality of sources of flavour in a single filter segment of the filter of the invention. This advantageously is further enhancing the flavouring possibilities and the amount of flavour which can be used . For example, the use of a capsule and a flavour thread located in the same filter segment is not practical, as these would occupy the same space in the segment.

During use, the filter wrapper is exposed to for example heat or vapour, thereby releasing the flavour contained in the menthol patch. In the preferred embodiment where the filter comprises not only the menthol patch but also the flavourant inserted object such as a capsule, the consumer may experience both an automatic flavouring released from the menthol patch and a consumer triggered flavouring, released, for example, from the ruptured capsule.

Moreover, other objects, such as non-cuttable flow restrictors, can be present in a single filter segment of the filter of the invention. As the volume occupied by the menthol patch is almost negligible, the placement of comparatively bulky flavouring elements, such as for example a flavour thread or a non-cuttable object like a rupturable capsule, is facilitated .

Both flavouring and non-flavouring filter inserted object, where the inserted object is in contact with the inner rod surface of the wrapper, can be placed and secured to the correct position within the filter by the menthol patch. To that effect, the menthol patch is suitably located depending on the filter design and construction. In this preferred embodiment, the menthol patch thus has an additional purpose of attaching both plug of acetate tow and the filter inserted object to the wrapper.

According to a preferred embodiment, the inner surface of the wrapper further comprises an adhesive patch. An adhesive patch is defined as a patch comprising adhesive, wherein adhesive is a substance the main function of which, as understood by a person skilled in the art, is to adhere or bond items together. Adhesives are typically organized by the method of adhesion. These are then organized into reactive and non-reactive adhesives, which refers to whether the adhesive chemically reacts to harden. Alternatively, adhesives can be organized by whether the raw stock is of natural, or synthetic origin, or by their starting physical phase such as for example liquid or solid.

The adhesive patch comprises preferably hot melt adhesive, such as a polyester adhesive. The adhesive patch including hot melt adhesive is referred to as the first adhesive patch. Alternatively or in addition, the adhesive patch comprises an emulsion-type adhesive such as polyvinyl acetate (PVA) and its derivatives, usually referred to as cold melt. The adhesive patch including cold melt adhesive is referred to as the second adhesive patch.

According to a preferred embodiment, the adhesive patch is located in the seam area of the inner surface of the wrapper, in other words it is located in proximity of the longitudinal edge of the inner surface of the wrapper, so that the longitudinal seam of the wrapper is bonded using adhesive. Preferably, the adhesive patch located in the seam area comprises the first adhesive patch, which means that it comprises hot melt adhesive.

It has been realized that, in correspondence to the seam of the wrapper, a long lasting gluing effect is desired, in order to avoid the unintended detachment of the wrapper from the plug after the production of the finished tobacco product. A lifting of a portion of wrapper in correspondence of the seam, creating the so-called "flag effect", is particularly undesired. Therefore, a long lasting glue such as the cold melt glue is preferred. However, during production at high speed, it may be necessary to employ an adhesive that quickly develops adhesion between two bodies. For this purpose it may be advantageous to use a hot melt adhesive. Preferably, the first adhesive patch comprises a stripe of hot melt adhesive located along the edge of the inner surface of the wrapper. Hot melt adhesive can be degraded by menthol . Therefore, the filter of the invention preferably includes a protective element for the first adhesive patch. More preferably, the protective element includes an additional adhesive patch located between the first adhesive patch and the menthol patch. Even more preferably, the additional adhesive patch is located within the seam area. Preferably, the additional adhesive patch comprises a second adhesive patch such as cold melt adhesive.

Preferably, the menthol patch is located in the inner rod surface only and the menthol patch does not extend into the seam area of the wrapper.

In the inner rod surface, which means in the area of the inner surface of the wrapper outside the seam area, according to a preferred embodiment of the invention, the plug is attached to the wrapper only via the menthol patch. In other words, the menthol patch is the only bond used to make the wrapper adhere onto the plug . In such an embodiment, the adhesive patch or patches located substantially at one edge of the inner surface of the wrapper form the seam that glues the wrapper onto itself, without contact to the plug .

According to a different embodiment, a combination of a menthol patch or patches and second adhesive patch or patches is realized in the inner rod surface of the wrapper in the filter of the invention in order to anchor the plug onto the wrapper.

In the known art, during filter manufacture, generally some adhesive is placed on the continuous wrapper web on which a stream of tow is laid down. Due to the relatively high radial stress present between the tow and the wrapper, it is preferred that the adhesive used anchors the tow on the wrapper as quickly as possible. For this purpose, preferably hot melt glue is applied . It has been noted that the adhesive properties of menthol are similar to those of the hot melt glue, therefore either one or a plurality of menthol patches alone, or menthol and hot melt glue patches, are used to anchor the plug on the wrapper outside the seam area in the preferred embodiment of the invention to achieve this goal.

According to a preferred embodiment, the menthol patch comprises a stripe - in the following called menthol stripe - disposed along the longitudinal direction of the plug . More preferably, the menthol stripe extends for the total longitudinal length of the filter. This is a particular simple design that allows the application of the menthol through a nozzle at high machine speed.

In the embodiment where the filter comprises both one or more menthol patches and adhesive patches, preferably the menthol patches and adhesive patches are disposed substantially parallel one to the other along the wrapper. Preferably, both menthol patches and adhesive patches comprise menthol stripes and adhesive stripes, respectively. This latter preferred embodiment allows an easy manufacture of the filter of the invention without substantial or complex modifications of the known apparatus for the production of filters at high speed.

However, in different embodiments, the menthol patch may be disposed on the inner rod surface in many other different ways, for example diagonally with respect to the plug longitudinal direction. Moreover, the menthol patches may form a predetermined selected pattern on the inner rod surface of the wrapper, for example the menthol patches can form an intermittent stripe, a wavy line, a dotted line, or any other chosen pattern.

The variety of available shapes is possible due to the fact that the at least partial substitution of the standard glue known in the art with one or more menthol patches as specified in the invention does not substantially change the adherence strength of the wrapper to the plug.

According to the invention, there is provided a filter for a smoking article according to the above described.

The present invention further provides a method for manufacturing a filter for a smoking article, the method comprising : wrapping a wrapper around a longitudinally extending surface of a plug of filtration material; and attaching said plug to said wrapper by means of a menthol patch.

Preferably, the method of the invention further includes melting menthol crystals and depositing the melted menthol onto the wrapper in order to form the menthol patch. Menthol is generally solid and in crystal form at room temperature. Therefore commercially available menthol, sold generally in form of menthol crystals, is preferably first melted to obtain liquid menthol. The liquid menthol is then deposited on the inner surface of the wrapper so that the menthol patch having the specific desired shape is formed . The patch of liquid menthol is then brought into contact with the filter material, for example the acetate tow, before the liquid menthol hardens. Once the liquid menthol cools down, it forms a bond between the filter material and the wrapper.

According to another aspect, the invention provides an apparatus for the manufacture of flavoured filters, the filter including a wrapper, the apparatus comprising : a supply for advancing a continuous web of wrapping material; a supply for advancing a tow material for the formation of a filter plug; a discharger configured to discharge menthol so as to form a menthol patch on the wrapping material; and a wrapping device for wrapping the advancing web around the tow, so that the web is attached to the tow by means of the menthol patch before the wrapper is closed around the filter material. Preferably the tow material is attached at least partially to the wrapper by means of the menthol patch.

Preferably, the apparatus also includes a cutter for cutting the resulting wrapped tow into segments of predetermined length.

Applicants have noted that a substantially standard apparatus for the production of filters can be used also for the production of the filter of the invention at high speed . More precisely, the apparatus of the invention for the manufacture of flavoured filters does not need complex modifications with respect to an apparatus of the prior art. This allows a rather easy and cost effective conversion of the known apparatuses in order to produce the flavoured filter of the invention.

According to a preferred embodiment, a single discharger configured to discharge the menthol so as to form the menthol patch and further configured to discharge adhesive so as to form an adhesive patch is present, in order to minimize space occupancy. More preferably, the aforementioned single discharger comprises two separate nozzles, one for discharging adhesive so as to form the adhesive patch and the other for discharging menthol so as to form the menthol patch onto the web.

The discharger may be configured to discharge a continuous menthol patch, so as to create a continuous longitudinal stripe of menthol along the web or intermittently. This allows for the production of a plurality of distinct menthol patches on the web of wrapper material. For example, in case of multi-components filters having a plurality of plugs, the spacing between the plurality of plugs may preferably be flavourant-free.

In an additional embodiment of the invention, a plurality of dischargers are present in the apparatus of the invention, so as to create a plurality of separated menthol patches on the web. Alternatively or in combination, a discharger including a plurality of nozzles for the formation of a plurality of parallel stripes of menthol may be included . This additional discharger of menthol can be located downstream or upstream the location of the discharger of adhesive. The terms "downstream" and "upstream" refers to the direction of advancing of the continuous web of wrapping material .

According to a different embodiment of the invention, the discharger configured to discharge menthol so as to form a menthol patch comprises a drum having a plurality of grooves. Preferably, the grooves are realized in a predetermined pattern on a circumferential surface of the drum. In this embodiment, the drum is coupled to the apparatus of the invention in such a way that it rotates while contacting the web of wrapper material. The grooves are continuously filled with liquid menthol. The liquid menthol is in turn discharged onto the web due to the drum rotation. Preferably, the movement of the web puts the drum into rotation. The menthol is therefore disposed onto the web according to the pattern of the grooves on the drum, creating a menthol design on the web and therefore on inner rod surface of the final filter. Each groove therefore may form one or more different menthol patches onto the wrapper web.

In addition, the combination of the drum above and the discharger having the nozzle configured to create a continuous or intermitted menthol patch or a continuous or intermitted adhesive patch may be envisaged as well.

The present invention also relates to a method of using an applicator nozzle in a filter making machine to apply at least one patch of melted menthol to a wrapper material in order to attach a filter component to the wrapper before the wrapper is closed around the filter material.

Such a filter component may be filtration material such as for example acetate tow, crimped paper or a non-cuttable object like for example a flow restrictor.

Further advantageous aspects of the invention become apparent from the following description of embodiments of the invention with the aid of the attached figures in which : Fig. 1 is a schematic perspective view of a smoking article realized according to the invention :

Fig. 2 is a top view of a wrapper of a filter for the smoking article of Fig. 1 realized according to the invention;

- Fig. 3 is a front view in section of the smoking article of Fig. 1;

Fig. 4 is a top view of a wrapper analogue to the top view of Fig. 2 according to a different embodiment of the invention;

Fig. 5 is a perspective view of a multi-component filter according to an embodiment of the invention;

- Fig. 6 is a schematic side view of an apparatus for the manufacture of flavoured filters according to the invention;

Fig. 7 is a schematic side view of a detail of the apparatus of Fig. 6 according to an additional embodiment of the invention;

Fig. 8 is an enlarged view of a detail of the apparatus of Figs. 6 or 7; - Fig . 9 is a top view of a wrapper realized using the apparatus according to the invention including the detail of Fig . 8.

With initial reference to Fig. 1, a smoking article realized according to the teaching of the present invention is globally indicated with 1.

The smoking article 1 includes a filter cigarette comprising a cylindrical elongated tobacco rod 2 attached at one end to an axially aligned, elongated, cylindrical filter 4. Tobacco rod and filter extend longitudinally along a common X axis. The wrapped tobacco rod 2 and the filter 4 are joined in a conventional manner by tipping paper (not visible in the appended drawings), which circumscribes the entire length of the filter 4 and an adjacent length of the wrapped tobacco rod 2. The filter 4 comprises a generally cylindrical plug of filter material, for example acetate tow. The cylindrical plug of filter material comprises one or more segments, each of which may have a different material composition.

An example of a filter 4 in accordance with the invention is described with reference to Fig. 1. The filter 4 includes a single plug 5 of filter material that has first and second generally circular end faces 11, 12 and a longitudinally extending surface 13 substantially perpendicular to the first and second end faces 11, 12.

The plug of filter material 5 in the filter 4 is wrapped by a layer of sheet material in the form of a wrapper, or plug wrap 20. As shown by Fig . 1 and 3, the plug wrap 20 is wrapped around the longitudinally extending surface 13 of the plug 5 so as to leave the first and second end faces 11, 12 of the plug 5 open.

Moreover, plug 5 includes a filter inserted object 80, in this case a substantially centrally located capsule, filled with flavourant such as menthol, depicted with a circle in the section of Fig. 3. Different positioning and type of filter inserted objects are also possible.

With reference to Fig. 5, a different embodiment of the filter of the invention is shown. The filter 400 includes a plurality of filter segments, such as white plug 5, restrictor 4b and carbon plug 4c coaxially positioned along the longitudinal direction X.

A preferred embodiment of wrapper 20 is shown in an enlarged view in Fig. 2 disassembled from smoking article 1, and it can be used both in filter 4 and 400. It is to be understood that all preferred embodiments of wrapper 20 are applicable both to filter 4 and 400, unless otherwise stated. The wrapper 20 defines an inner surface 21 in contact to the plug 5 and an outer surface 22 (the outer surface 22 being visible in the drawings only with reference to Fig. 3) in contact with the exterior to the smoking article. Moreover, for a given portion of the inner and of the outer surface, the inner and outer surface overlap so as to form a longitudinal seam 30 to hold the wrapper 20 in place around the plug 5. The inner surface 21 is delimited by a first and second longitudinal edge 25, 26, substantially parallel one to the other, and includes a seam area 23 and an inner rod surface 24. The distance between the first and the second longitudinal edges 25,26 defines the width of the wrapper 20, for example between about 24 mm and about 30 mm, preferably, about 27 mm. The seam area 23 is the portion of the area of the inner surface which includes the seam 30 and the overlapping area between inner and outer wrapper surface 21,22. The inner rod surface 24 is the area of the inner surface which is in contact to the longitudinal surface 13 of the plug 5.

According to the invention, the filter 4, 400 includes a menthol patch 50 on the inner surface 21 of wrapper 20 used to attach the wrapper 20 to the plug 5. The menthol patch 50 is applied to the wrapper 20. The shape and thickness of the menthol patch 50 are arbitrary and some examples are given with reference to the appended drawings of the preferred embodiments.

The plug 5 is attached to the wrapper 20 by means of the menthol patch 50 before the wrapper 20 is closed around the filter 4.

In Fig. 2, the wrapper 20 includes a plurality of menthol patches 50, all having the shape of a rectangle, and all rectangles being substantially aligned along the longitudinal axis X of the inner surface 21. The resulting pattern is substantially that of an intermittent stripe. The menthol patch is realized in the inner rod surface 24.

In another embodiment, not shown, the menthol patch includes a single continuous menthol stripe 50 which extends substantially for the complete longitudinal length of the inner surface 21 of wrapper 20 realized on the inner rod surface 24. Preferably, the single menthol stripe is substantially aligned along the longitudinal axis X of the inner surface 21.

Alternatively, according to the embodiment of Fig. 4, the wrapper 20 includes two menthol patches, all indicated with 50 each of which has the shape of a menthol stripe which extends substantially for the complete longitudinal length of the inner surface 21 of wrapper 20. The two menthol patches 50 are substantially parallel to each other and are both realized in the inner rod surface 24.

According to another non-depicted additional preferred embodiment, the menthol patch includes a plurality of substantially parallel stripes extending substantially for the complete longitudinal length of the inner surface 21 of the wrapper 20. Preferably, the plurality of menthol stripe are also substantially all aligned along the longitudinal axis X of the inner surface 21.

In the embodiment of Fig . 4, preferably the width of the menthol stripe is between about 0.5 mm and about 8 mm. In addition, preferably the distance D between two different menthol stripes is at least 1 mm.

Alternatively, the inner rod surface 24 of the wrapper 20 includes a single "wide" menthol patch in form of a wide menthol stripe. Preferably the width of the menthol stripe is of at least 5 mm.

According to alternative preferred embodiments, the wrapper 20 in its inner rod surface 24 includes a plurality of menthol patches having a more complex design. In Fig. 9, the menthol patches have each the shape of an interrupted stripe, and they are all disposed perpendicularly with respect to the longitudinal extension of the wrapper and substantially parallel one to the other. The length of the various menthol stripes may vary. According to a different embodiment, not shown, the wrapper includes two menthol patches, each patch extending along the whole longitudinal length of the inner rod surface 24 of wrapper 20, and having each a substantially sinusoidal shape. Alternatively, the wrapper 20 includes a plurality of menthol patches 50, each of which having the shape of a menthol stripe, and the menthol patches being arranged on the inner surface 21 of wrapper 20 diagonally with respect to the longitudinal extension of the inner rod surface 24 of wrapper 20. The diagonal menthol patches 50 are moreover substantially parallel one to the others. In an additional embodiment, not depicted in the appended drawings, the inner surface 21 of a wrapper includes a plurality of menthol patches 50, the patches defining a "unit" having the shape of a rectangle and two dots positioned in a specific pattern, repeated regularly several times along the X axis. "Patch units", which are preferably repeated several time for the complete length of the wrapper 20, can have many different alternative patterns.

In the wrapper 20 of filter 400 depicted in Fig. 5, a plurality of rectangular-shaped menthol patches 50 are present, located in correspondence of some, but not all, of the filter segments. In the embodiment of Fig. 5, two menthol patches are present in correspondence of the longitudinal axial location of the plug 5 and of the carbon plug 4c, but no menthol patch is located in the longitudinal position corresponding to the restrictor 4b location.

Moreover, the filter 4,400 may include, on the inner surface 21 of wrapper 20, an adhesive patch. The shape and the thickness of the adhesive patch are also arbitrary.

Preferably, the filter 4,400 includes a first adhesive patch 51 including hot melt glue realized in correspondence to the seam area 23 of the inner surface 21 of the wrapper 20. According to a preferred embodiment, the first adhesive patch 51 is located along the longitudinal edge of the inner surface of the wrapper, so that the longitudinal seam 30 of the wrapper is bonded using hot melt glue. Preferably, the first adhesive patch 51 has the shape of an adhesive stripe and even more preferably it extends for the complete length of the longitudinal edge 26 of the wrapper 20.

The first adhesive stripe 51 located along the longitudinal edge 26 in the seam area 23 of the wrapper 20 is shown for example in the Figs. 2 and 4. As it becomes clear from Fig. 3, the first adhesive stripe 51 forms seam 30.

In addition, preferably the filter 4,400 includes a second adhesive patch 52 realized in cold melt glue. Preferably, the second adhesive patch 52 is realized between one of the longitudinal edges 25,26 of the inner surface 21 of wrapper 20 and the menthol patch 50. More preferably, the second adhesive patch 52 is realized in the seam area 23 between the first adhesive patch 51 and the menthol patch 50, as shown in Figs. 2 and 4. The second adhesive patch 52 in these preferred embodiments has the shape of an adhesive stripe and it is realized along the complete longitudinal length of the wrapper 20. Preferably, first and second adhesive patches 51, 52 do not intersect.

According to the preferred embodiment of Fig. 4, two second adhesive patches 52 are realized in the inner surface 21 of the wrapper, both of them located between one of the longitudinal edges of the wrapper and the menthol patch 50. One of the two second adhesive patches is located in the seam area 23, the other is located in the inner rod surface 24.

The width of the first or the second adhesive patch 51,52 is preferably between about 0.8 mm and about 1.8 mm. In the embodiment of Figs. 4, the distance between the two second adhesive stripes is equal to about 12 mm.

The wrapper 20, in any of the preferred embodiment described, is wrapped around the longitudinally extending surface 13 of plug 5, and the wrapper 20 is fixed to itself by the first adhesive patch 51 forming the seam 30, where the inner and the outer surfaces 21,22 overlap. Wrapper may be fixed to itself also by means of the second adhesive patch 52, if present. The plug 5 is attached to the inner rod surface 24 of wrapper 20 by means of the menthol patch 50 and, if present, by means of the second adhesive patch 52.

In case of a multi-component filter 400, some of the filter segments, or the filter inserted object 80, can be attached to the inner rod surface 24 wrapper by means of the menthol patch 50, such as in the embodiment of Fig. 5. According to the invention, the filter 4,400 is realized by means of an apparatus for the manufacture of flavoured filters, globally indicated with 100 and schematically depicted in Figs. 6 and 7.

Fig. 6 shows a portion of the apparatus 100, in which with 20a it is denoted an elongated continuous web of wrapping material (for example a web of paper) which is to be subdivided in a series of wrappers 20. The web is shown in a lateral view as a continuous line which advances in direction indicated by arrow 99 and it is moved in such a direction by a continuous belt 71 or other means known in the art. Apparatus 100 further includes a source (not shown) of a continuous strand of filter or tow material to be cut in order to form filter plug 5. The continuous strand is indicated with 5a and it is drawn also in the direction of arrow 98.

Objects are optionally inserted in the tow material for example by means of an apparatus for introducing objects in the continuous flow of filter material as described in the international application WO-A- 2012/076496 and not shown in the appended drawings.

The continuous web and tow strand are then put into contact, in particular the tow strand 5a is laid down on the web 20a.

Located upstream, with respect to the web or strand movement, the meeting point between tow strand and web, the apparatus 100 further includes a discharger 72 configured to discharge menthol so as to form the menthol patch 50 on the continuous web 20a of wrapping material.

The discharger 72 includes an applicator 73 and one nozzle 74. The nozzle 74 includes an orifice (not visible in the drawings) for the discharge of menthol and an inlet (also not shown) which receives menthol from a conduit 76 which delivers menthol from a reservoir.

Due to the fact that generally commercially available menthol is in the form of menthol crystals, apparatus 100 also preferably comprises a heater (not shown) in order to warm up the menthol crystals present in the reservoir and melt the liquid menthol, before conveying the melted menthol to the discharger 72 via conduit 76.

The apparatus 100 can include, additionally to discharger 72, other additional dischargers, all indicated with 82 and depicted with dotted lines in Fig . 6, discharging adhesive in order to form the first or the second adhesive patch 51,52 or both. The additional dischargers 82 may be located either upstream or downstream the menthol discharger 72.

Alternatively, with reference to Fig . 7 according to a different embodiment of the invention, discharger 72 includes two or more nozzles, 74 and 75 for the discharge of menthol as above described . Further nozzles for the discharge of a first adhesive, a second adhesive or both a first and a second adhesive may be present. Discharger 72 may include more than two nozzles. However, the nozzles are arranged such that mixture of the different add on materials (for example liquid menthol, hot melt, cold melt) is avoided .

In a different embodiment, the discharger 72 includes a rotating drum 78 having a plurality of grooves 77, realized in its circumferential surface, in which the menthol is placed . The drum 78, visible in Fig . 8, replaces the discharging nozzle 74, and is mounted on the apparatus 100 in order to rotate on the continuous web 20a discharging the menthol on the web during the rotation. Alternatively drum 78 and discharger 72 for the discharge of menthol can be both present to realize different menthol patterns. Moreover, further dischargers, such as discharger 82 for the discharge of first or second adhesive or both a first and second adhesive may also be present. In this embodiment, the menthol patch 50 is therefore formed on the continuous web 20a according to the grooves' 77 pattern.

For example, with reference to the wrapper 20 of the embodiment of Fig. 9, the depicted pattern of the menthol patches 50 on its inner surface 21 may be realized using drum 78 of Fig . 8, wherein a plurality of stripe- like grooves 77 disposed perpendicular to the rotation direction of the drum 78 are realized. Alternatively, the non-depicted embodiment having the two sinusoidal menthol patches 50 of the wrapper 20 can be realized using drum 78 in which two corresponding sinusoidal grooves 77 are formed on the surface of the drum. Alternatively, diagonal patches 50 are formed onto wrapper 20 by diagonal grooves 77 formed on the drum 78. The pattern of menthol patches "units", realized for example by the various positioning of dots and rectangles is obtained by a corresponding pattern of dot-like and rectangular grooves 77 on drum 78.

Apparatus 100 further preferably comprises an additional discharger 79, located downstream the meeting point between web and tow strand, where the hot melt glue is discharged to form the first adhesive patch on the web 20a.

Downstream the discharger 79 for hot melt glue, a wrapper unit 83 to wrap the web around the tow is also included, so that the hot melt glue forms seam 30. Preferably, means for reducing the temperature of the hot melt after application to the wrapper is provided to facilitate the hardening of the hot melt.

Preferably, a cutter (not shown) is then dividing the continuous tow surrounded by the wrapper into single double or multiple filter rods 4,400.

Claims

1. A smoking article, comprising a filter, the filter comprising :

- a plug of filter material having a longitudinally extending surface;

- a wrapper wrapped around the longitudinally extending surface of the plug; and

- an inner surface of said wrapper facing said longitudinally extending surface of said plug comprising a menthol patch, wherein the menthol patch is applied to the wrapper and the plug is attached to the wrapper by means of the menthol patch before the wrapper is closed around the filter material.

2. The smoking article, according to claim 1, wherein the menthol patch comprises at least 99% of 2-isopropyl-5-methylcyclohexanol.

3. The smoking article, according to claim 1 or 2, including an adhesive patch realized on the inner surface of the wrapper.

4. The smoking article, according to claim 3, wherein said adhesive patch comprises hot melt adhesive forming a first adhesive patch or said adhesive patch comprises polyvinyl acetate forming a second adhesive patch.

5. The smoking article, according to claim 3 or 4, in which the adhesive patch is located in a seam area of the inner surface, so that a seam formed by one edge of the inner surface overlapping the wrapper surrounding the plug is adhesively bonded by the adhesive patch.

6. The smoking article, according to claim 4, in which the second adhesive patch is located in an inner rod surface of the inner surface.

7. The smoking article, according to any of claims from 4 to 6, wherein the first adhesive patch or the first and the second adhesive patches are located in the seam area of the inner surface.

8. The smoking article, according to any of the preceding claims, comprising a filter inserted object, preferably, said object comprising flavourant.

9. The smoking article, according to claim 8, wherein said object is attached to the inner surface of the wrapper by means of the menthol patch.

10. A filter for a smoking article, the filter comprising :

- a plug of filter material having a longitudinally extending surface;

- a menthol patch realized on an inner surface of said wrapper facing said longitudinally extending surface of said plug, wherein the menthol patch is applied to the wrapper and the plug is attached to the wrapper by means of the menthol patch before the wrapper is closed around the filter material.

11. A method for manufacturing a filter for a smoking article, comprising :

- wrapping a wrapper around a longitudinally extending outer surface of a plug of filter material;

- attaching said plug to said wrapper by means of a menthol patch.

12. The method according to claim 11, wherein the attaching comprises:

melting menthol crystals;

- depositing the melted menthol onto said wrapper inner surface.

13. An apparatus for the manufacture of flavoured filters, said filter including a wrapper, said apparatus comprising :

- a supply for advancing a continuous web of wrapping material;

- a supply for advancing a tow material for filter plug;

- a discharger configured to discharge menthol so as to form a menthol patch on the continuous web of wrapping material; and

- a wrapper for wrapping the advancing web around the tow, so that the tow material is attached at least partially to the wrapper by means of the menthol patch before the wrapper is closed around the filter material.

14. The apparatus according to claim 13, including :

- a further discharger configured to discharge adhesive so as to form an adhesive patch on said continuous web of wrapping material .

15. Method of using an applicator nozzle in a filter making machine to apply a menthol patch to a wrapper material in order to attach at least one filter component to the wrapper before the wrapper is closed around the filter material.