EP2088877B1

EP2088877B1 - Cigarette filter with flavored particles

Info

Publication number: EP2088877B1
Application number: EP07845536.7A
Authority: EP
Inventors: France Cote; Jacinthe Larochelle
Original assignee: Imperial Tobacco Canada Ltd
Current assignee: Imperial Tobacco Canada Ltd
Priority date: 2006-11-29
Filing date: 2007-11-16
Publication date: 2018-08-01
Anticipated expiration: 2027-11-16
Also published as: TR201815890T4; EP2088877A1; CA2667633C; WO2008064463A1; JP2013226156A; AR064042A1; CO6210714A2; ZA200902917B; MY160632A; BRPI0719373A2; CA2667633A1; RU2462964C2; EP2088877A4; RU2009124595A; WO2008064463A8; BRPI0719373B1; KR20090112642A; PL2088877T3; KR101552736B1; JP2010510780A

Description

BACKGROUND OF THE INVENTION

(a) Field of the invention

The present invention relates to a novel smoke-enhancing filter rod; a smoking article comprising said smoke-enhancing filter rod; and a method for the preparation of said smoke-enhancing filter rod.

(b) Description of Prior Art

In the United States patent no. 3,771,534 entitled "Combination filter and cigarette holder", a filter cartridge is integrated to a cigarette holder. Two barrels are aligned and of their ends of similar diameter, one is connected to the cigarette to be smoked, and the other to a short length of cigarette acting as a tip. The filter cartridge can be impregnated with a volatile oil such as menthol or mint in order to flavor smoke, and the two barrels act as air chambers to cool it. The aim of such conception essentially resides in the double filters providing protection against infectious substances. However, the customer is presented with a poor flavoring of the smoke, the cooling of the smoke being an obstacle to the adhesion of the flavor. Moreover, it has been shown that menthol and volatile oils present an unpleasant aftertaste to certain groups of customers.
In United States patent no. 3,972,335 entitled "Mentholated cigarette filter", a flavored cigarette filter made of granular activated carbon, known for its efficient capacity for filtering gas phase toxic agents in the smoke, is treated so that its shelf life and delivery rates of the flavoring-agent are improved. Indeed, the carbon is treated with sucrose, or any material capable of being absorbed and retained by the activated carbon as well as act as a pore-modifying agent: its effect consists in blocking the most retentive portions of the carbon, so that the less retentive ones remain available for adsorption of the smoke-flavored agent such as menthol. Thus, the flavor agent is retained on the carbon during shelf life, but is released when measured and chosen so that only the most retentive pores are made unavailable. Such situation often ends up in inefficient filtering of the smoke's deleterious agents and very low delivery of the flavorants, the pore-modifying agent blocking most of the retentive spots on the carbon.
United States patent no. 4,620,554 entitled "Moderating agent of cigarette taste ", a moderating agent of the cigarette taste is attached to the top end of the cigarette and providing both flavoring of the smoke but also elimination of the nicotine taste. Such moderating agent is constituted from a blend of powder material. The purpose of such invention is to provide improvement of the smoke's nicotine taste and reduce the related irritancy. However, this invention is mainly intended to enhance the taste of tobacco as well as diminish and camouflage the unpleasant taste and aftertaste of the cigarette's smoke caused by nicotine and other components.
United States patent no. 4,889,144 entitled "Filter for tobacco smoking" is based on the conception of a flavored cigarette filter. The filter tip comprises a space in its middle filled with flavored-sealed particles. Those flavored-sealing particles are made of a natural polysaccharide, a diluent agent as well as one or more flavor materials selected from a variety of powdered and oil-soluble flavors: some of the most popular ones are licorice, clove, cinnamon powder and vanilla, lemon, Japanese mint oil. Such encapsulation provides protection of the flavors against volatilization and deterioration. In order to release the flavor, the capsules have to be broken by the smoker by the application of a force on the outer surfaces of the filter that is greater than the one normally applied when smoking, such as twisting or pressing the filter. Destruction-accelerator particles, which are particles such as crystalline sugars and table salt with a greater hardness than the one of the flavor particles, can be added to increase speed of the flavor particle destruction. In conclusion, such product gives the smoker the ability to enjoy either a flavored cigarette or an original one by not breaking the flavor particles. This invention can be seen as a breakthrough in the cigarette flavoring industry: however, the main problem with a filter tip comprising a cavity in its center filled with flavor particles is that very often, those particles tend to compact and that the draw resistance increases. Thus, those cigarettes tend to be difficult to smoke and customers disinterest themselves from such product.
United States patent application no. 2005/0070409 A1 entitled "Method and apparatus for incorporating objects into cigarette filters" relates to the conception of a new method for mechanically incorporating individual objects in cigarette filters. The resulting filter rods have objects imbedded in the web filter such as flavorant containing capsules.
It would be highly desirable to be provided with a cigarette constructed with a filter providing a certain level of protection, adding to the smoke's natural taste a desired flavor, enhancing its overall essence and offering a better and more subtle aftertaste. Indeed, the technologies presented in the prior art often end up overfiltering smoke to the point where its taste is altered and often has to be re-flavored through passage in a second filter containing flavorants. Such inventions are often intricate and many result in a diminution of the overall quality, taste and aftertaste of smoke and cigarette.

SUMMARY OF THE INVENTION

Herein we report smoke-enhancing filter rods produced through different methods and comprising various smoke-enhancing plant flavour particles as a means for enhancing the smoke of a smoking article. Indeed, the smoke-enhancing filter rods of the present invention are made of a filtering-zone, in which smoke-enhancing plant flavour particles are present. Smoke-enhancing plant flavour particles may be embedded or inserted in a cavity in the filter. The filtering zone is made of a material chosen from cellulose acetate tow, cellulose acetate web and paper. Such filter material can be dyed to conform to the color of the smoke-enhancing plant flavour particles. The smoke-enhancing plant flavour particles may be flavorant plant particles chopped to a size suitable to be embedded or inserted in a cavity in said filtering zone and chosen from mint, vanilla, peppermint, anise, basil, bay leaves, cardamom, cinnamon, coriander, cumin, ginger, nutmeg, oregano, paprika, rosemary, saffron, sage, thyme, vanilla, lavender, licorice, coffee, tea, eucalyptus, clove, wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, rose, bergamot and orange blossom. The mint particles may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens. The smoke-enhancing plant flavour particles may also be a combination of natural flavorant plant particles blended with menthol and/or essential oils and/or one or more of their constituents. The smoke-enhancing plant flavour particles are prepared by finely chopping dry plant parts such as leaves and/or stems to a size of 10 to 80 meshes. The smoke-enhancing filter-rod is prepared in one preferred embodiment by uniformly sprinkling a suitable amount of smoke-enhancing plant flavour particles on a tow traveling laterally on a mechanical support. The tow used for the preparation of such filter is a laterally widened tow and sprinkling of the smoke-enhancing plant flavour particles is effected through passage of said tow at a certain speed under an apparatus distributing said particles. The sprinkled tow is then formed into a thin rod-shaped bundle, coated with lapping paper [plugwrap] and cut into rods of predetermined size in order to produce the smoke-enhancing filter rods. The resulting filter rod can either be prepared using a single segment of smoke-enhancing plant flavour particles embedded in the filter material or a combination of segments of regular filter material continuously linked with segments of smoke-enhancing embedded filter material. The smoke-enhancing filter rod is also prepared, in a second preferred embodiment, by filling a cavity between two segments of regular filter material with smoke-enhancing plant flavour particles. Also filter rod can include multiple segments some of which may contain other particles embedded therein, such as charcoal and resin among others.
Those rods are hereinafter incorporated into a smoking article: the filter is continuously connected to a tobacco rod, a cylindrical rod of smokable filler material, by wrapping the two axially aligned parts in an end-to-end relationship with tipping material.
For the purpose of the present invention, the following terms are defined below.
As used herein the terms 'smoking material rod' or 'smoking material' are merely intended to mean that part of the smoking article which is contained within the substantially non-combustible wrapper and should not have imported therein any association as to the combustibility or otherwise of individual components of the rod of the smoking material.
The term 'carbon' as used herein can be taken to cover a material which is substantially solely carbon and any carbon precursors, such as carbonaceous material. As used herein the term carbonaceous includes material which has been pyrolysed, which material preferably contains carbon, although some incomplete combustion products may still be present. Ready pyrolysed coconut fibre may, for example, be the carbonaceous material from which carbon is derived.
As used herein, the term 'smoking material' means any material which can be used in a smoking article. It does not necessarily mean that the material itself will necessarily sustain combustion. The smoking material is usually produced as a sheet, then cut. The smoking material may then be blended with other materials to produce a smokable filler material.
The term "smoke-enhancing" is referring to an ability to provide improved features to the smoke of a smoking article. Such features are the result of the presence of specific particles in the filter of a smoking-device: depending on the type of particles, as smoke passes through the filter, it can be flavored, improve aftertaste's quality and/or add a refreshing taste.
The expression "smoke-enhancing plant flavour particles" is referring to natural flavorant plant particles and to a combination of natural flavorant plant particles blended with menthol and/or essential oils.
The expression "flavorant" is referring to the ability of smoke-enhancing plant flavour particles to flavor the smoke produced by a smoking-device as it drawn through the filter in which they are embedded which releases, produces, neutralises, masks or alters odours, for example a perfume or deodorant.
The term "smoking article" is referring to an apparatus for smoking tobacco comprising a rod of smokable material, such as tobacco, enclosed in a circumscribing material connected to a filter by wrapping material. Such smoking article, when lit, produces the smoke that will be drawn through the filter. Such smoking articles include cigarettes, cigars and cigarillos. Other smokable materials, include reconstituted tobacco, and tobacco substitutes, and alternative smoking products in which the material is not smoked/burned as such.
The term "natural flavorant plant particles" is referring to particles of any plant parts having flavorant properties, which can be used in order to flavor the smoke of a smoking article. Those flavoring plant parts comprise, but are not limited to, flowers, beans, fruits, leaves, stems and roots.

DETAILED DESCRIPTION OF THE INVENTION

Smoking Article Structure

The length of the smoking material rod is advantageously at least 60 mm and the rod should preferably yield not less than six puffs, and more preferably not less than seven puffs when smoked under standard machine smoking conditions. The rod is preferably of uniform cross-sectional shape and dimensions throughout the length of the rod.

Filter

Advantageously the smoking article incorporates a filter element which may be conventional fibrous cellulose acetate, polypropylene or polyethylene material or gathered paper material. Multiple filter elements may also be utilised. Filter elements having particular pressure drop characteristics, such as the filter sold by Filtrona and known as The Ratio Filter, may also be utilised. Disposed upon or within the material of the filter element may be further flavouring materials, as described above, which are released or eluted from the filter element by the aerosol generated by the heated or burnt aerosol generation means.
Preferably the filter element may further contain particulate material, such as granular carbon, which may suitably be activated carbon. Preferably the activated carbon is activated coconut carbon. The filter containing particulate material may be a dual filter comprising, for example, a cellulose acetate mouth section and a dalmatian rod at the tobacco end of the filter. A paper section may also form part of a multiple filter. Alternatively, the filter may be the filter manufactured in accordance with the structural design of the filter known as the Active Patch filter (manufactured by Filtrona International) as described in UK Patent Specification No. 2249936 . In a yet further alternative, the filter element may be cavity filter comprising two end sections with a central cavity containing granular material.
The filter element may alternatively be a selective reduction filter as described in co-pending US Provisional Patent Applications Serial Nos. 60/309,388 and 60/309,435 both filed on 1st August 2001 .
The mouth end located filter plug may be made from a variety of material, for example, cellulose acetate tow, cellulose, paper, cotton, polypropylene web, polypropylene tow, polyester web, polyester tow or combinations thereof.
In addition, the pressure drop and/or mechanical filtration efficiency of the filter plug sections can be selected to achieve the desired smoking mechanics and filtration characteristics as may be required with the specific product design desired.
A further filter construction that may be useful in the present invention is that described in our co-pending International Patent Application No. PCT/GB02/005603 . The grooved arrangement of the filter described therein provides for ventilating air to enter grooves extending towards the tobacco end and then be re-directed towards the mouth end. The result is a decrease in the CO/tar ratio. In combination with particulate additives that selectively reduce vapour phases a significant reduction in vapour phase constituents can be achieved.
It is much by preference that a first portion of the tobacco smoke filter comprises an adsorbent material. Preferably the adsorbent material is a general adsorbent. The general adsorbent material is preferably selected from a group of relatively high surface area materials, such as activated charcoal, which are capable of adsorbing a range of chemical compounds without a high degree of specificity.
It is much by preference that the second portion of the smoke filter of the present invention comprises a conventional smoke filtration material. Suitable conventional materials include cellulose acetate, paper, polypropylene and other materials that will be well known to persons skilled in the art and capable of retaining at least a portion of the particulate phase of smoke.
Preferably the first and second portions of the smoke filter of the present invention are arranged in co-axial alignment.

Wrapper

The wrapper enwrapping the smoking article may comprise a burn additive, such as sodium and/or potassium citrate, for example. Other suitable burn additives, such as sodium or potassium salts, such as acetate and tartrate; mono-ammonium phosphate, and di-sodium hydrogen phosphate, for example, will be known to the skilled man. Advantageously the burn additive is present in the range of 0.5-2.5% by weight of the wrapper. The wrapper may also have a basis weight in the range of 20-40g/m².
The wrapper of the smoking article may alternatively or in addition be a non-paper wrapper, such as the wrappers described in International Patent Applications, Publications Nos. WO 96/07336 and WO 01/41590 . Such wrappers assist in the reduction of sidestream smoke components, but still provide a smoking article which has burning and ashing characteristics similar to conventional products, i.e. the wrappers allow the smoking article to burn down and ash in a similar way to conventional products.
The wrapper may suitably be a paper wrapper or a substantially non-combustible wrapper, such as that described in WO 96/07336 . The subject matter of that application as it relates to the substantially non-combustible wrapper is incorporated herein by reference. The wrapper thereof advantageously contains at least 65% inorganic particulate filler material, such as those inorganic materials described above.
A conventional cellulose pulp paper wrapper may have a permeability in the range 2-300 CU and preferably less than 100 CU. Such a wrapper may also be a low total filler paper such as disclosed in European Patent Application No. 0 404 580 and comprising less than 14% magnesium oxide or hydroxide, for example.

Smokable Material

Preferably the smokable material is a tobacco material. Suitably the tobacco material comprises one or more of stem, lamina, tobacco dust. It is preferred that the tobacco material comprises one or more of the following types: Virginia or flue-cured tobacco, Burley tobacco, Oriental tobacco, reconstituted tobacco. It is much by preference that the smokable material comprises a blend of tobacco material. Advantageously the smokable material comprises 10-80% Virginia tobacco, 10-60% Burley tobacco, 0-20% Oriental tobacco, 0-120% reconstituted tobacco and 0-30% expanded tobacco.
The smoking material of smoking articles according to the subject invention preferably comprises or consists of cut tobacco, a proportion of which tobacco may be expanded tobacco. The smoking material may comprise reconstituted tobacco or tobacco substitute material.
The smokable filler material may also comprise a burn additive to enhance the smoking properties of the filler material. Depending on the properties of the filler the burn additive is either a burn promoter or a burn retardant. Suitable burn additives may be selected from one or more of salts of Group I or II metals such as acetates, citrates and other burn promoters known to the skilled man. Suitable burn retardants include magnesium hydroxide, mono-ammonium phosphate or magnesium chloride, for example.
The smokable filler material may also comprise an ash improver, which is advantageously present in the filler in the range of 0-5%. Appropriate ash improvers include one or more of mica, perlite, clays, such as, for example, vermiculite, kaolinites, talcs, saponites, bentonites, as well as ash improvers such as disodium hydrogen orthophosphate, sodium carbonate or diammonium phosphate, for example.

Inorganic Filler Material

Advantageously the inorganic filler material is one or more of perlite, alumina, diatomaceous earth, calcium carbonate (chalk), vermiculite, magnesium oxide, magnesium sulphate, zinc oxide, calcium sulphate (gypsum), ferric oxide, pumice, titanium dioxide, calcium aluminate or other insoluble aluminates, or other inorganic filler materials. The density range of the materials is suitably in the range of 0.1-5.7 g/cm³. Advantageously, the inorganic filler material has a density that is less than 3 g/cm³, and preferably less than 2.5 g/cm³, more preferably less than 2.0 g/cm³ and even more preferably less than 1.5 g/cm³. An inorganic filler having a density of less than 1 g/cm³ is desirable. A lower density inorganic filler reduces the density of the product, thus improving the ash characteristics.

Organic Filler Material

The smokable filler material may also comprise an organic filler. Advantageously the organic filler material is inert or relatively inert when alone i.e. will not readily maintain burning, but in a mixture may become more combustible, i.e. will maintain burning. Suitable organic fillers include insoluble alginates, such as calcium or magnesium alginate, calcium pectinate or alginic acid, as well as non-modified cellulose, such as treated or non-treated wood pulp or alpha cellulose, for example. Mixtures of inert organic fillers and inorganic fillers may also be used.

Aerosol Generating Means

The aerosol generating source preferably comprises aerosol forming means, such as glycerol and/or other aerosol forming compounds illustrated in our co-pending PCT Application No. WO 96/07336 . These include polyhydric alcohols, propylene glycol and triethylene glycol, esters such as triethyl citrate, triacetin or triethylene glycol diacetate (TEGDA), or high boiling point hydrocarbons. Other suitable aerosol forming means will be known to those skilled in the art.

Binders

Advantageously, if the binder is a mixture of alginate and non-alginate binders, then preferably the binder is comprised of at least 50% alginate, preferably at least 60% alginate and even more preferably at least 70% alginate. The amount of combined binder required may suitably decrease when a non-alginate binder is utilised. The amount of alginate in a binder combination advantageously increases as the amount of combined binder decreases. Suitable alginic binders include soluble alginates, such as ammonium alginate, sodium alginate, sodium calcium alginate, calcium ammonium alginate, potassium alginate, magnesium alginate, triethanol-amine alginate and propylene glycol alginate. Other organic binders such as cellulosic binders, gums or gels can also be used in combination with alginic binders. Suitable cellulosic binders include cellulose and cellulose derivatives, such as sodium carboxymethylcellulose, methyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose ethers. Suitable gums include gum arabic, gum ghatti, gum tragacanth, Karaya, locust bean, acacia, guar, quince seed or xanthan gums. Suitable gels include agar, agarose, carrageenans, furoidan and furcellaran. Starches can also be used as organic binders. Other suitable gums can be selected by reference to handbooks, such as Industrial Gums, E. Whistler (Academic Press).

Colouring Agents

Colouring means, such as food grade dyes, for example, or colourants such as liquorice, caramel or malt, or extracts thereof, may be used to darken the colour of the filler material. The presence of vermiculite or other inorganic material, such as iron oxide, may also give a darker colour to the filler material of the smoking article.
Suitable colourant materials include cocoa, liquorice, caramel, chocolate or toffee, for example. Finely ground, granulated or homogenised tobacco may also be used. Industry approved food colourants may also be used, such as E150a (caramel), E151 (brilliant black BN), E153 (vegetable carbon) or E155 (brown HT). Other casing materials may also be suitable. In the alternative, the presence of vermiculite or other inorganic filler materials may give a darker colour to the smoking material.
Preferably the colourant is present from 0-10% and may be as much as 5-7% by weight of the final smoking material. Advantageously the colourant is less than 7% preferably less than 6% and more preferably less than 5% of the final smoking material. Much preferred is use of colourant at less than 4%, less than 3% and less than 2%. Cocoa may suitably be present in a range of 0-5% and liquorice may be present in a range of 0-4%, by weight of the final smoking material. When the colourant is cocoa or liquorice, for example, the minimum amount of cocoa to obtain the desired sheet colour is about 3% and for liquorice is about 2%, by weight of the final smoking material. Similarly, caramel may suitably be present in a range of 0-5 %, preferably less than about 2 % by weight of the final smoking material, and more preferably about 1.5 %. Other suitable colourants include molasses, malt extract, coffee extract, tea resinoids, St. John's Bread, prune extract or tobacco extract. Mixtures of colourants may also be used.
A range of tests made on a panel of smokers and evaluating the smoking properties and overall acceptability of cigarettes made with such smoke-enhancing filters have shown favorable results in comparison with already marketed products. Compared to mentholated cigarettes, prepared with natural menthol crystals or synthetic menthol crystals, this invention presents multiple advantages. Indeed, here is provided smoke-enhancing plant flavour particles embedded or inserted in a cavity, such as mint particles, in the filter [this could be clearer, perhaps by referring simply to the particles being in the filter, with further additional possibility that they may be embedded in the filter material itself or may be provided in a cavity of the filter] providing a minty flavor and a refreshing taste and aftertaste to the smoke as it passes through it, comparatively with the overly intense taste and cooling aftertaste of the mentholated product.
In accordance with the present invention there is provided a smoke-enhancing filter rod according to claim 1.
In accordance with one embodiment of the present invention, the particles to be embedded in the first segment of the smoke-enhancing filter rod are chosen from known mint varieties including Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Mentha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens. The preferred mint variety used in accordance with the present invention is Mentha Arventis.
In accordance with another embodiment of the present invention, the type of material used for the filtering zone of the smoke-enhancing filter is chosen from any cellulose acetate tow, cellulose acetate web and paper. The preferred material used in the present invention is cellulose acetate. The filtering material is usually in the form of a fibrous tow, but may also be in other physical forms such as crimped sheet in the case of paper.
In accordance with an embodiment, the type of smoking article to be attached to the smoke-enhancing filter can be chosen from cigarette, cigars and cigarillos.
The present invention will be described with reference to the various stages of production of the final product comprising a method for fabricating the smoke-enhancing plant flavour particles, the smoke-enhancing filter rod and the smoking article containing said filter.
The smoke-enhancing plant flavour particles consist of flavorant plant particles or flavorant plant particles blended with menthol and/or essential oils and/or one or more of their constituents. The main aim associated with the use of plant particles in the smoke-enhancing filter rods instead of artificial purified agents is to provide the consumers with natural flavorant agents, in combination or not with menthol and/or essential oils and/or one or more of their constituents, and thus a product with a refreshing taste and improved aftertaste. The plant particles comprise every usable part of a chosen plant such as the roots, leaves, flowers, stems or buds. They are collected, dried and mechanically chopped to a suitable size to be embedded in the filter rod. The preferred humidity percentage of the particles to be incorporated being from 10 % to 20 %, whereas the normal degree of humidity of a cigarette being from 10 to 14 % obtained by either drying or not. In one preferred embodiment, natural mint particles are being used for flavoring the smoke. Various studies comparing the use of natural mint particles in a filter of a smoking-device were conducted to compare the smoking article with a commercially available menthol cigarette. First, studies on loading, flavor retention and overall taste in a prolonged amount of time of natural greenhouse and field mint particles when incorporated in a filter were conducted. Those tests demonstrated that natural mint particles presented different flavoring properties than the already marketed flavoring products. Moreover, smoke tests established that the characteristic taste and aftertaste of natural mint, which is the result of a combination of a multitude of components is providing a refreshing taste and improved aftertaste compared to a strong cooling effect of a current menthol product.
Flavorant particles can be incorporated in a filter rod through various techniques: the particles can be contained within a cavity in the filter rod or applied on and/or in the filter material.
"Dalmatian-filters" may be made according to known techniques. For example, "Dalmatian-filters" consist of filtering material through which smoke-enhancing plant flavour particles have been sprinkled before it has been folded and wrapped in wrapping material. Various steps are needed to lead to the conception of such filter: first, the filter material is wound in a roll from which it is continuously drawn. The laterally widened, flat material is brought to a smoke-enhancing particle dispersing section by a mechanical support. A hopper is provided above the rotary dispersion roller and a guide case is provided in front of it. The smoke-enhancing plant flavour particles fed in the hopper are uniformly applied to the filter material that is being continuously fed below the rotary dispersion roller. One important detail to be noted here is that the filter material on which smoke-enhancing plant flavour particles are sprinkled can be dyed for aesthetic reasons.
After the dispersion of the particles is completed, the filter material is brought to a second section wherein the folding operation is effected. A filter material folding section is used to fold the filter material. A retainer plate projecting from the machine body is provided horizontally through a gap corresponding to a thickness of the filter material above another upper surface of a receiving plate projecting from the same machine body. A pair of curved rods obliquely closed to each other on the front side of the retainer space are provided on a mount rod projecting from the machine body. A curved portion of each rod is provided in order to depress downwardly both edge portions of the filter material. A pair of clamping thin plates are provided on both sides on the upper surface of the retainer plate for clamping, folding and gathering at the center the edge portions, downwardly depressed and inwardly pressed by the curved portions of the curved rods. The clamping thin plates are arranged so as to intersect with each other, the distance between the clamping plates and the retainer plate is increased toward the rear side and the opposite edge portions are drawn inwardly to each other by the feed of the material. At the same time, the edge portions are overlapped to form the overlapping portion which is fed in this state. Accordingly, the opposite edge portions of the filter material lap the smoke-enhancing plant flavour particles, which is led to the sleeve portion of the forming section. After introduction of the filter material into the sleeve portion, it is gathered into a thin rod shaped-bundle containing the embedded particles and subsequently coated with a lapping paper (plug wrap), porous or non-porous. Thereafter, the filter is cut into rods of predetermined length in the cutter section.
Filters can also be configured as a combination of segments of various filter materials, physical forms and/or composition wherein smoke-enhancing plant flavour particles are present in different locations along the length of the rod. Such construction can provide various advantages compared to the regular "dalmatian filter" in terms of general appearance, resistance to draw. These particular filter rods are made of two types of segments present in alternation in the rod and maintained together by lapping paper. Indeed, a combination of two to five segments of either filter material embedded with flavorant particles or regular filter material are continuously connected in the rod and, depending on the total number of segments, are known as "dual-dalmatian filter", "triple-dalmatian filter", "quadruple-dalmatian filter" and "quintuple-dalmatian filter". The filters may be symmetrical, when the segments are all of the same size, or asymmetrical, when two or more of the segments are of different lengths.
The first type of segmented filter rods is the "dual-dalmatian filter" comprising a segment of smoke-enhancing plant flavour particles embedded filter material as well as a segment of regular filter material. The segment of the filter located adjacent to tobacco rod is the segment comprising embedded smoke-enhancing plant flavour particles in order to flavor the smoke being drawn through, whereas the segment located at mouth end is made of regular filter material, produced exactly as the "dalmatian-filter" but without the step consisting of sprinkling smoke-enhancing plant flavour particles. Such a construction is interesting for two reasons. First, the presence of a segment of regular filter material at the mouth end of the cigarette prevents the smoke-enhancing plant flavour particles to fall out of the cigarette during manipulation by the consumer.
A second configuration of segmented filter rods consists of "triple-dalmatian filter rods". This type of filter, comprising two or three different segments, one configuration option is as follows: the segments adjacent to the tobacco rod and to the mouth end are both made of regular filter material whereas the segment located between the later two is made of filter material embedded with smoke-enhancing plant flavour particles. Therefore, the smoke is flavored as it passes through the filter and the appearance of the product is the same as the one of regular cigarettes.
Another filter configuration is a triple-dalmatian filter where the mouth end segment is a regular filter, the middle segment is embedded with mint particles and the tobacco rod segment is embedded with charcoal and/or resin particles among others.
One variety of triple filter distinguishes itself from already described "triple-dalmatian filter rods". Indeed, the "cavity filter" constitutes an alternative for the flavoring of the smoke as it is conceived as a filter rod comprising 2 segments separated by a cavity containing smoke-enhancing plant flavour particles. Therefore, instead of two regular segments separated by a particles embedded segment, the segments are separated by pure free smoke-enhancing plant flavour particles inserted in a cavity in the filter. Such construction is again appealing for consumers because the product has the same appearance as regular cigarettes and has interesting flavoring properties.
"Quadruple-dalmatian filter" and "quintuple-dalmatian filter" are filter rods having a configuration option in accordance with one embodiment of the present invention consisting of an alternation of four or five segments of regular filter material and of filter material embedded with smoke-enhancing plant flavour particles. The various segments are disposed in the filter rod in such an order that a segment of regular filter material is present at the mouth end. The presence of a multitude of segments in the filter rod makes it possible to present consumers with a variety of products. Indeed, the various segments embedded with smoke-enhancing plant flavour particles can be prepared using either a variety or identical smoke-enhancing plant flavour particles and/or charcoal and resin, among others. Therefore, the resulting product can present a smoke that is more concentrated in flavor or a smoke characterized by a blend of flavors, thus permitting better modulation of its taste and aftertaste.
As previously established, a variety of smoking articles can be attached to this type of filter and the procedure is the following. The smoking article is prepared by filling a cylindrical open-ended rod with smokable filler material. Such material normally consists of a blend of shredded tobacco which composition can vary, the existing varieties being flue-cured, burley, Oriental, Maryland, dark, dark-fired and Rustica tobaccos as well as rare and specialty tobacco. The circumscribing wrapping material of the tobacco rod can vary in composition and properties. One end of the tobacco rod is the lighting end whereas the other one is adapted to be linked to the filter. The filter and the tobacco rod are prepared with similar diameter and are axially aligned in an end-to-end relationship before being attached to one another by tipping material. Filter ventilation can be done through preperforated tipping or laser perforation on line.
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.

Claims

A smoke-enhancing filter rod for a smoking article, the filter rod comprising:
a first segment comprising a filter material and smoke-enhancing plant flavour particles dispersed within said filter material, said plant flavour particles being particles of mint plant leaves and/or particles of mint plant stems, said plant flavour particles being plant particles chopped to a size of 2mm to 0.177mm (10 to 80 meshes); and

a second segment comprising a regular filter material,

wherein the second segment is arranged to be disposed at a mouth end of the smoking article and is configured to prevent said smoke-enhancing plant flavour particles from falling out of the smoking article.
The filter according to claim 1, wherein said smoke-enhancing plant flavour particles are a combination of natural flavourant plant particles blended with menthol and/or essential oils.
The filter according to claim 1, wherein said filtering zone is made of a material chosen from cellulose acetate tow, cellulose acetate web and paper.
The filter according to claim 3, wherein said tow is dyed.
The filter according to any one of the preceding claims, wherein said mint plant is chosen from Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Mentha Iongifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens.
A smoking article comprising a smoke-enhancing filter rod according to any one of claims 1 to 5, continuously connected to a tobacco rod.
A smoking article comprising a smoke-enhancing filter rod according to any one of claims 1 to 5, said smoking article constituted of a combination of segments of filter material embedded with smoke-enhancing plant flavour particles in alternation with segments of filter material embedded or not with other particles, continuously connected to a tobacco rod.
The smoking article according to claim 7, wherein said other particles are selected from charcoal, resin and plant particles.
The smoking article according to claim 7 or 8, wherein said combination of segments of smoke-enhancing filter rod and segments of filter material consists of an association in alternation of three, four or five segments.
A method for producing smoke-enhancing filter rods according to claim 1, said method comprising uniformly sprinkling a suitable amount of smoke-enhancing plant flavour particles on a tow traveling laterally on a mechanical support prior to forming said tow into a filter rod,
wherein forming the tow into a filter rod comprises the steps of forming the sprinkled tow into a thin rod-shaped bundle, cutting it into segments of a predetermined size, preparing the segments into the desired configuration before coating it with lapping paper and cutting it into rods of filter of a predetermined size,
wherein preparing the segments into the desired configuration consists of preparing combinations of segments of filter material embedded with smoke-enhancing plant flavour particles and of segments of filter material,
wherein said segments of filter material consist of regular filter tow shaped into a thin rod bundle and cut into segments of a predetermined size, and
wherein the segment arranged to be disposed at the mouth end of the smoking article is a segment of regular filter material, and
wherein said smoke-enhancing plant flavour particles are prepared by finely chopping particles of leaves and/or stems to a size of 10 to 80 meshes.