Claims:1) A centre-filled smoking tobacco article to deliver a uniform smoke profile comprising:
a) an annular region,
b) an inner core region and
c) optionally a filter portion,

wherein said inner core region comprising tobacco and/or non-tobacco materials selected from specially processed tobacco, cut rolled tobacco stem, expanded tobacco, dry ice expanded tobacco (DIET) tobacco, extruded tobacco, neutral filler sheets (NFS), reconstituted tobacco sheet, humectants, aerosol generating mixture, aromatic/flavor generating substances;

wherein said annular region and said inner core region being present in a weight ratio between 45-95% to 5-55%;

wherein said centre-filled smoking tobacco article, have 17% to 20% pressure drop than the smoking articles in the blended form.

2) The centre-filled smoking tobacco article as claimed in claim 1, wherein said annular region occupies the periphery of the centre-filled smoking tobacco article.

3) The centre-filled smoking tobacco article as claimed in claim 1, wherein said annular region comprises the cut tobacco material which is a straight grade and/or blend, wherein the size of lamina is preferably ranges from 22-40 cpi and the size of the stem preferably ranges from 130-160 cpi with moisture content of 13-14%.

4) The centre-filled smoking tobacco article as claimed in claim 1, wherein said humectants is selected from polyhydric alcohols, aliphatic esters of carboxylic acids and volatile flavoring agents and tobacco flavor modifiers such as cocoa, licorice and sugars.

5) The centre-filled smoking tobacco article as claimed in claim 4, wherein said polyhydric alcohols are selected from glycerine, propylene glycol, triethylene alcohol and tetra ethylene alcohol in the range of 0-60 wt%.

6) The centre-filled smoking tobacco article as claimed in claim 1, wherein said aromatic/flavor generating substances is selected from clove, cardamom, coffee beans, mint or the like.

7) The centre-filled smoking tobacco article as claimed in claim 1, wherein said inner core region is formed of ovoidal, elliptical, round, spherical or the like, which is substantially circular in shape.

8) The centre-filled smoking tobacco article as claimed in claim 1, wherein said filter portion is made up of cellulose acetate fibers and/or PLA fibers to form segmented filter, recess/reverse recess filter, cavity filter, multi-component filter, or ventilated filter.

9) The centre-filled smoking tobacco article as claimed in any of the preceding claim which delivers uniform smoke profile and leaves substantially no perceivable traits including but not limited to stain, punctured marks or the like on the surface of the said articles.

10) A method of making centre-filled smoking tobacco articles as claimed in any of claims 1 to 9, such that said centre-filled smoking tobacco articles leaves no substantial stains on the maker, said method comprising:
(i) providing tobacco material through a tobacco infeed hopper, said infeed hopper consisting three chambers wherein atleast one chamber holds tobacco material for inner core region and atleast two chambers to hold tobacco material for annular region;
(ii) passing the tobacco material through a trough guide means which receives both annular and core portion in layers; and
(iii) forming rod like centre-filled combustible articles by a converging means.
, Description:Field of the invention

The present invention relates to center-filled articles, specifically combustible articles such as cigarettes, cigar and also includes non-combustible articles which generates aerosol upon heating (e.g. Heat-not-burn cigarettes) and a method of making the same.

Background and the prior art

Significant efforts are being done to enhance the quality of the smoking product with reduce the cost and creating a differentiated product. To manufacture cigarettes with different specific weight along with fragile materials is always challenging. For instance adding flavored ingredients like clove into the combustible article (e.g. cigarettes) involves technical complexities. In case of cigarettes manufacturing, lots of quality and machine runnability issues are inevitable. Few of the issues that are generally faced in the industry are smoke perception, physical appearance and machine runnability. Smoke perception for example smoke perception varies from cigarette to cigarette or within the length of the same cigarette. This is due to improper blending of flavored ingredients. Issues related to physical appearance may be perceivable and substantial increase in body marks, puncturing on the surface of the cigarettes. Machine runnability issues may be due to high tackiness and high bulk modulus of the flavored ingredients. Addition of flavors into a combustible article affects the runnability of the machine.
There are various attempts have been made related to co-axial cigarettes. For example GB250063 proposes a cigarette having more than two segments composed of tobaccos of varying strength gradations. However GB250063 focuses on blending different grades of tobacco in a cigarette.

US3902504 discloses an "engineered cigarette" wherein rods are manufactured containing varying quantities of tobacco and tobacco substitute. The rods are wrapped and cut into segments, and then segments are arranged in a preselected pattern and joined by an overwrap to produce a segmented cigarette. US3759267 discloses a cigarette having two portions, one of natural tobacco and the other of a different type of tobacco or tobacco substitute, arranged as adjoining wedges, which is similar though not the same as a product manufactured by the method and apparatus of the present invention. The cigarette here has a frusto conical center with the core forming the blend and outer annular part forming the filler section. Moreover, the cigarette would be prepared by hand and is hence not efficient. The method for manufacturing this cigarette disclosed in US3880171 illustrates the great difficulty in manufacturing. The apparatus disclosed in the patent differs radically from conventional cigarette making equipment, requiring specialized trimming and cutting apparatus to remove portions of the first blend carried on a perforated conveying belt. US4874004 and US6067995 also relate to co-axial cigarettes. US 4,874,004 relates to a coaxial cigarette comprising an inner core of a material which glows substantially residue-free, in particular tobacco material, a wrapper for the inner core, an outer jacket of a tobacco and/or non-tobacco material surrounding the inner core or its wrapper respectively, and a wrapper for the outer jacket. The wrapper in US4874004 can be tobacco foil, sheets of tobacco or other natural materials. US4874004 offers an advantage of coaxial cigarette with coaxial filter and also requires a separate sheet/foil (wrapper).

US 6,067,995 relates to co-axial cigarettes. Further it relates to a coaxial cigarette including a rod comprising a rod core, a rod core wrapping, a rod jacket and a rod jacket wrapping; and a filter comprising a filter core, a filter core wrapping, a filter jacket and a filter jacket wrapping, wherein a cross stream barrier (smoke flow stopper) is provided between said rod core and said filter jacket and/or said rod jacket and said filter core in the zone joins said rod core wrapping and said filter core wrapping. The disadvantages of US 6,067,995 are the usage of wrapping across rod core, rod jacket, rod jacket, filter jacket which is more expensive and complex to make. For instance, US 6,067,995 teaches the use of smoke flow stoppers in the cigarette that covers both a portion of the filter core wrapping and the rod core wrapping is highly complex and undesirable.

US 5713377 relates to a coaxial tobacco cartridge with an inner core of a first tobacco blend, a sheath for the inner core, an outer jacket of a second tobacco blend, a sheath of high air permeability and an associated filter element. By the coaxial arrangement of two different tobacco blends in the inner core and outer jacket of the tobacco cartridge, it is possible to achieve effects that are not obtainable with a single tobacco blend. The coaxial tobacco cartridge, according to this invention is not smokeable independently, but can be used by persons to make their own coaxial cigarettes, by inserting it in an appropriate cigarette-paper tube or wrapping it in a cigarette-paper strip. US ‘377’ describes that distinctly different flavor trends can be achieved with the tobacco cartridges attached to specific filter elements. It is further exemplified that Burley and Virginia tobacco varieties represents one such possible flavor variations by different tobacco blends in the inner core and in the outer jacket. The invention also discusses the possibility of incorporating aromatic substances such as menthol to the outer jacket and the inner core of the cartridge. The disadvantage of these cigarettes cartridges are that these comprises outer jackets which the consumer has to further roll with a sheath of permeable cigarette paper or such material. Further, US ‘377’ describes a cartridge which demands an inner sheath of paper or tobacco film.

US 4716913 relates to an improved composite cigarette comprising a core of lesser quality tobacco smoking material surrounded by an annulus of higher quality tobacco smoking material. The improvement resides in the provision of an increased quantity of the annulus material at the lighting end of the cigarette, so as to provide economic use of tobacco, increase the initial flavor impact and thereby provide more uniform smoke taste characteristics along the length of the cigarette. The invention also provides a method of making the said composite cigarettes. US 4716913 describes to fill the inner core with lesser quality tobacco from the point of view of cost saving.

GB2229078 discloses a process for making a cigarette filter which includes applying a flavour or additive on one or more of the faces of the wrapping material which contacts the filter material. The filter can have an inner fibrous core 1 wrapped with an impervious film 2 and an outer fibre tow 3 with a paper wrapper 4. The flavour or additive is applied to the inner surface 5 of outer wrapper 4 or to the inner surface 7 or the outer surface 6 of the inner wrap 2. GB2229078 is carried out on process of making cigarette filter rods, basically filter rod formation has done with co axial core construction having different density of filter material used and also filter wrapping material inner surface applied with a flavor or additives or one or more faces of wrapping material which will have the direct contact with filter material. Thus the taste of the flavor or additives drawn in to the filter material when the cigarette is smoked and the enhanced flavor will transfer to smoker and is not desirable. This has the disadvantage of flavor being located at the surface of a barrier (the paper) which prevents distribution of flavor within the filter material.

US4874004 discloses a coaxial cigarette comprising an inner core of a material, which glows substantially residue-free, in particular tobacco material, a wrapper for the inner core, an outer jacket which consists of a tobacco and/or non-tobacco material and coaxially surrounds the inner core and its wrapper, and a wrapper for the outer jacket, has a ventilated coaxial filter with a filter core, the internal diameter of which corresponds substantially to the diameter of the inner core, and with a filter jacket; the filter core has an air-impermeable wrapper; the filter jacket has an air-permeable wrapper; the wrapper of the inner core and the wrapper of the outer jacket are provided with glow agents; and the draw resistance of the inner core is lower than the draw resistance of the outer jacket.

The coaxial cigarette of the US pat no. ‘004 comprises a rod portion 12 to which a coaxial filter 15 is attached with the usual production techniques. The rod portion 12 contains an inner core 14 having a wrapper 16 and an outer jacket 18 having a wrapper 20. Hence the construct of the cited prior art and the objective is entirely different from the proposed invention. The present invention does not have such wrapper surrounding the inner core.

US5388596 discloses a coaxial cigarette comprising a coaxial tobacco rod of a core and a rod periphery which contain different mixtures, the sheaths of the rod core and the rod periphery consisting of combustible material and a filter mouthpiece being provided at one end of the coaxial tobacco rod; according to the invention, the ratio of the draw resistance of the core per unit length to the packing density thereof lies in the range from about 0.13 to about 0.27 mm WC cm2 /mg whilst the ratio of the draw resistance per unit length of the rod periphery to the packing density thereof lies in the range of about 0.07 to about 0.11 mm WC cm2 /mg; the filter mouthpiece is a conventional preferably ventilated filter.

The objectives of US pat no. ‘596 and the present invention are entirely different and offers a different value proposition. ‘596 relates to coaxial cigarettes, however through a different construct which states that “the coaxial tobacco rod 12 consists of a core 14 and a periphery or jacket 18. The core 14 is provided with a sheath 16 consisting generally of cigarette paper or tobacco sheet. The periphery 18 is also surrounded by a sheath 20 likewise consisting of cigarette paper or tobacco sheet.” The two segments have a sheath per se surrounding core and the periphery which is not the subject matter of the present invention and it may not provide the uniform smoke profile as demonstrated in the present invention.

US8573230 discloses a smoking article having a cylindrical tube of smokable material having an outer wrapper, a concentric rod of smokable material coaxially positioned within the cylindrical tube of a smokable material, and an inner wrapper separating the cylindrical tube and the concentric rod. A filter attaches to the tobacco rod with an annular film positioned between the filter and the tobacco rod. The annular film increases the resistance-to-draw of the cylindrical tube during smoking.

US20070137667 relates to a smoking article having a cylindrical tube of smokable material having an outer wrapper, a concentric rod of smokable material coaxially positioned within the cylindrical tube of a smokable material, and an inner wrapper separating the cylindrical tube and the concentric rod. A filter attaches to the tobacco rod with an annular film positioned between the filter and the tobacco rod. The annular film increases the resistance-to-draw of the cylindrical tube during smoking.

The objectives of the present invention and both the above cited arts US Pat. No. ‘230 and ‘667 is very different from the present invention. Both the prior arts relates to cigarettes to have greater filtering efficiency and higher levels of dilution, there has arisen a need for a smoking article having a structure that better controls the tar concentration in the mainstream smoke, enhances the transfer of flavor and tar diluents, minimizes the migration of flavor and aerosol formers in the tobacco rod, and controls the composition of the side-stream smoke. The cigarette design of ‘230 consists of an inner wrapper 60 separates the cylindrical tube 22 and the concentric rod 24. Further the annular film present in the cigarette design of 230 patent increases the resistance-to-draw which leads to increased pressure drop which is not the objective of the present invention.

None of them related to a cost effective, simple process to make smoking articles, particularly cigarettes, wherein at least one flavor ingredient(s) or other form of tobacco is placed as an inner core, surrounded by rest of tobacco blend. The composition of inner core also includes neutral fillers and other materials with desired flavor. The cigarettes made out of this process have uniform smoke characteristics, without any perceivable traits such as punctured marks or stains or then like. On the finished product, post-use or during-use or while storage, it does not interfere with the product quality.

Object of the invention

It is an object of the present invention to overcome the drawbacks of the prior art.

It is also an objective of the present invention to provide a material to be added uniformly along length of the combustible article to maintain uniform smoke profile.

It is yet another objective of the present invention to add flavored ingredient into the core of the centre-filled article, wherein it does not puncture or stain or leave any perceivable marks on the surface of the product.

It is an objective of the present invention to add fragile/brittle materials, neutral filler sheet, expanded tobacco, recon, neutral filler sheets into the combustible product with less degradation.

Summary of the invention

According to one aspect of the present invention there is provided a centre-filled smoking tobacco article to deliver a uniform smoke profile comprising:

a) an annular region;
b) an inner core region; and

c) optionally a filter portion
wherein said inner core region comprising tobacco and/or non-tobacco materials selected from specially processed tobacco, cut rolled tobacco stem, expanded tobacco, dry ice expanded tobacco (DIET) tobacco, extruded tobacco, neutral filler sheets (NFS), reconstituted tobacco sheet, humectants, aerosol generating mixture, aromatic/flavor generating substances;
wherein said annular region and said inner core region being present in a weight ratio between 45-95% to 5-55%;
wherein said centre-filled smoking tobacco article, have 17% to 20% pressure drop lesser than the smoking articles in the blended form.

According to another aspect of the present invention there is provided a method of making centre-filled smoking tobacco articles, such that said centre-filled smoking tobacco articles leaves no substantial stains on the maker, said method comprising:
(i) providing tobacco material through a tobacco infeed hopper, said infeed hopper consisting three chambers wherein atleast one chamber holds tobacco material for inner core region and atleast two chambers to hold tobacco material for annular region;
(ii) passing the tobacco material through a trough guide means which receives both annular and core portion in layers; and
(iii) forming rod like centre-filled combustible articles by a converging means.

Brief description of accompanying figures

Figure 1 illustrates the making of centre-filled articles such as cigarettes comprising tobacco hopper, partitioned into three chambers A, B, C with movable plates “A”, “B” and carded drums (large and small) which is picker roller.
Figure 2 illustrates the trough guide to receive the annular and inner portion of the centre filled combustible articles.
Figure 3 illustrates the formation of centre filled combustible articles within the trough guide (design configuration)
Figure 4 illustrates the convergence of different layers of tobacco to form centre-filled combustible articles.
Figure 5 illustrates that there is no visually perceivable stain or puncture marks on the centre-filled combustible articles of the present invention.
Figure 6 illustrates the centre-filled combustible articles wherein the inner / core portion is made up of non-tobacco material e.g. neutral fill sheets (NFS).
Figure 7 illustrates the centre filled article of the present invention

Detailed description of the present invention

The present invention provides a smoking article, particularly cigarette, wherein at least one flavor ingredient(s) or other form of tobacco is placed as an inner core, surrounded by rest of tobacco blend. The composition of inner core also includes neutral fillers and other materials with desired flavor.

The scope of the term “smoking article” of the present invention is not limited. Any object or device or tool or a thing or any item which aids in smoking is included. It further encompasses any conventional smoking means such as cigarettes, cigars, cheroots, heat-not-burn (HNB) smoking formats, electric or electronic vaping devices, ENDS, or any other format that uses tobacco and/or nicotine to generate aerosol.

Tobacco blend comprises of different grades of cut tobacco broadly classified as flue cured, air cured and burley type of tobacco.

The centre-filled smoking article of the present invention consists of two parts: Annular portion (periphery of cigarette) and inner core portion. Annular part of cigarette consist of cut tobacco material in the form of blend or straight grade (size of the lamina preferably between 22-40 Cuts per inch (CPI), stem size preferably between 130-160 CPI and moisture retained preferably at 13-14%). Whereas inner core portion of the cigarette material is essentially made of (i) any specially processed tobacco, cut rolled stem and also other form of tobacco materials like dry ice expanded tobacco (DIET) tobacco, fragile materials like extruded tobacco etc and (ii) non-tobacco aromatic material like cut and dried clove. The non-tobacco aromatic material can be added to the core portion of the cigarette in the range of 10 to 50%. Neutral filler materials like neutral filler sheets (NFS), menthol shredded sheet can also be present in the core of the cigarette upto 30% by weight.

The inner core region comprises of tobacco and/or non-tobacco materials selected from specially processed tobacco, cut rolled tobacco stem, expanded tobacco, dry ice expanded tobacco (DIET) tobacco, extruded tobacco, neutral filler sheets (NFS), reconstituted tobacco sheet, humectants, aerosol generating mixture, aromatic/flavor generating substances. Humectants are selected from polyhydric alcohols (such as glycerine, propylene glycol, triethylene alcohol and tetra ethylene alcohol) of about 0-60 wt%, aliphatic esters of carboxylic acids and volatile flavoring agents and tobacco flavor modifiers such as cocoa, licorice and sugars. The aerosol generating mixture is selected from polyhydric alcohols (such as glycerine, propylene glycol, triethylene alcohol and tetra ethylene alcohol), aliphatic esters of carboxylic acids, volatile flavoring agents and tobacco flavor modifiers such as cocoa, licorice, sugars, organic acids, and high fructose syrup. The aromatic/flavor generating substances is selected from clove, cardomom, coffee beans, and mint.
The aromatic material is conditioned to 35% moisture, bulked for two hours then cut in to 60 CPI and then dried down to 13 to 14% moisture. The aromatic material is fed through highly précised metering conveyor then to movable type of hopper system.

The composition comprising (i) specially processed tobacco and (ii) non-tobacco aromatic material can be placed in the core of tobacco rod using conventional cigarette making machine with an “additional set up”. The product thus obtained is at par with all sensory attributes with the traditional smoking article. The smoking article in accordance with the present invention provides an effective solution to the non-uniformity in mixing of tobacco with reconstituted tobacco or neutral filler shreds or special additives such as clove or specially processed tobacco. The present invention utilizes the addition of flavored ingredients such as clove in a much more effective way to provide a smoking product with consistent in smoke quality which offers a significant cost advantage.

The present invention more preferably relates to better utilization of tobacco and non-tobacco aromatic dried particles and filler material, to create differentiated smoking tobacco products with good sensory satisfaction in cost effective manner and at the same time deliver less undesired constituents in smoke. The present invention provides a product, which can be manufactured at higher productivity with higher level of customer satisfaction with consistent smoke profile.

The cigarette rod in accordance with the present invention can be attached to any filter such as coaxial, segmented, segmented with granules and active charcoal, plain acetate or any such combination thereof.

The present invention thus provides a material to be added uniformly along length of the combustible article to maintain uniform smoke profile. It ensures addition of flavored ingredient or humectants like glycerine into the core of the centre-filled article, wherein it does not puncture or stain or leave any perceivable marks on the surface of the product. It also enables addition of fragile/brittle materials, neutral filler sheet, expanded tobacco, recon, neutral filler sheets into the combustible product with less degradation.

The criticality of the present invention also lies in the composition of two different materials viz.,
1) annular region with any type of tobacco blend that can be used but with the desired wt% and 2) inner core with clove / flavor / humectants / neutral filler sheets / expanded tobacco and so on. The ratio between annular and inner core region is between 45-95% to 55-5% respectively. The inner / core region can also form a larger percent in the overall composition of the cigarette. It is not mandatory that inner core must always be smaller than the annular region. The advantage of this is to offer more flavor or any desired smoke characteristics or any other smokeable materials like neutral filler sheets or the like in the inner core region.
Annular (A, C region) – 45-95% range Inner (B region) 5-55% range
45 = 22.5 : 22.5 55
95 = 47.5 : 47.5 5

Beyond the said range, either it provides off taste, tend to puncture and cause stain on the surface of the cigarette articles, or leads to run ability issue. Any suitable flavour materials (e.g. menthol, basil) can be used and without any restrictions.

Method for making centre-filled articles in accordance with the present invention:

According to a preferred embodiment of the present invention the cigarette rod is made in a conventional cigarette maker namely Mk-8. Majorly, the system consists of hopper, carded drum, picker roller, chimney and suction chamber which has been substantially modified to make centre-filled articles and the method of making such articles are described in the present embodiment. The property of formation of layers of tobacco while traversing through suction band has been exploited in the present invention. For example, the tobacco hopper region is partitioned (movable plates “A” and “B” as shown in figure -1) into three chambers named as A, B, and C wherein A and C constitutes the annular portion (top and bottom layer) and B (central portion) is directed towards inner / core portion of centre filed combustible articles. As an example to get 30% by wt. of clove and 70% cut tobacco blend in the final cigarette, the hopper (area above the carding drum) is divided in the ratio of 35:30:35. To the middle partition the core constituent would be fed manually or through an external controlled feeding system. Assuming the machine speed of 2000 cigs/min and the 0.7 g weight of smoking mixture for a standard size cigarette, the flow of the core constituent should be 420g/min. This flow is maintained using feedback from retro reflective optical sensors which control the width of the movable plates (as shown in Fig 2) based on height of tobacco roll in middle partition. The process includes by adding tobacco material for annular portion in the chamber A and C; further the flavored materials e.g. clove or the like enters into the chamber B which forms the inner / core portion. The small and large carded drums as shown in figure 1, maintain a uniform flow of tobacco by maintaining height of tobacco roll.

The layer formation (three layers) then occurs in three progressive stages in the suction band through a trough guide, as illustrated in Figure 2. The top layer (1) of the annular portion(s) of the combustible article enters first through the trough guide and attaches to the moving porous band (figure-3). Subsequently, the middle portion (2) i.e. core (clove like flavored material) enters and forms the middle section and finally the last/bottom layer (1) which is also the annular portion is allowed to seal the design configuration as detailed in figure 3. This ensures that the shape of the final product including inner core portion formed is ovoid, elliptical, round, spherical or any of the shape which is substantially circular in shape (figure – 5). The top and bottom layers constitute the annular portion which is made up of the same tobacco blend.

Different tobacco layers (as derived from Figure 2) stuck to a porous band pass through a converging area to give it a final shape of cylindrical cigarette (figure 4). This process of making a smoking article is commonplace, where converging pieces called as shoe and tongue piece are used to give a cylindrical shape to the tobacco travelling on porous suction bands. To these centre filled flavoured cigarettes, multiple filter types like conventional mono-acetate, co-axial, mutli segment, PLA, flavor enhancing as well as capsule filters can be attached to further enhance the smoke. Further the said method of making centre-filled articles such as cigarettes on a cigarette maker leaves no substantial stains on the maker is an added advantage.

The present invention is now illustrated by way of non-limiting examples.

Example 1
The composition of the cigarette and process of preparing the cigarette in accordance with the present invention is as follows

Annular part Inner part
Flue cureed virginia –70
Glycerine q.s Clove 30%
Glycerine q.s

The cigarette rod is made in a conventional cigarette maker namely Mk-8. Majorly, the system consists of hopper, carded drum, picker roller, chimney and suction chamber which has been substantially modified to make centre-filled articles and the method of making such articles are described in the present embodiment. The property of formation of layers of tobacco while traversing through suction band has been exploited in the present invention. For example, the tobacco hopper region is partitioned (movable plates “A” and “B” as shown in figure -1) into three chambers named as A, B, and C wherein A and C constitutes the annular portion (top and bottom layer) and B (central portion) is directed towards inner / core portion of centre filed combustible articles. As an example to get 30% by wt. of clove and 70% cut tobacco blend in the final cigarette, the hopper (area above the carding drum) is divided in the ratio of 35:30:35. To the middle partition the core constituent would be fed manually or through an external controlled feeding system. Assuming the machine speed of 2000 cigs/min and the 0.7 g weight of smoking mixture for a standard size cigarette, the flow of the core constituent should be 420g/min. This flow is maintained using feedback from retro reflective optical sensors which control the width of the movable plates (as shown in Fig 2) based on height of tobacco roll in middle partition. The process includes by adding tobacco material for annular portion in the chamber A and C; further the flavored materials e.g. clove or the like enters into the chamber B which forms the inner / core portion. The small and large carded drums as shown in figure 1, maintain a uniform flow of tobacco by maintaining height of tobacco roll.

The layer formation (three layers) then occurs in three progressive stages in the suction band through a trough guide, as illustrated in Figure 2. The trough guide section coming in contact with the inner code has been modified to give a wedge profile to prevent the inner core from spreading to the regions where the annular tobacco passes through. The top layer (1) of the annular portion(s) of the combustible article enters first through the trough guide and attaches to the moving porous band (figure-3). Subsequently, the middle portion (2) i.e. core (clove like flavored material) enters and forms the middle section and finally the last/bottom layer (1) which is also the annular portion is allowed to seal the design configuration as detailed in figure 3. This ensures that the shape of the final product including inner core portion formed is ovoid, elliptical, round, spherical or any of the shape which is substantially circular in shape (figure – 5). The top and bottom layers constitute the annular portion which is made up of the same tobacco blend.

Different tobacco layers (as derived from Figure 2) stuck to a porous band pass through a converging area to give it a final shape of cylindrical cigarette (figure 4). This process of making a smoking article is commonplace, where converging pieces called as shoe and tongue piece are used to give a cylindrical shape to the tobacco travelling on porous suction bands. To these centre filled flavoured cigarettes, multiple filter types like conventional mono-acetate, co-axial, mutli segment, PLA, flavor enhancing as well as capsule filters can be attached to further enhance the smoke. Further the said method of making centre-filled articles such as cigarettes on a cigarette maker leaves no substantial stains on the maker is an added advantage.

Example 2

Experiments to demonstrate the effect on pressure drop and draw effort of the cigarette prepared in accordance with the present invention

The draw resistance of a cigarette, or other smoking article, is a major determinant of the draw characteristic(s) of the cigarette which are experienced by a smoker. The draw resistance of a cigarette refers to the resistance of the tobacco rod, and filter element if present, to air flowing there along. The draw resistance perceived by a smoker can be measured quantitatively by the pressure drop or difference in static pressure between the two ends of a sample cigarette at a fixed air flow rate of 17.5 ml sec-1. As used herein, the phrases 'cigarette pressure drop' or 'pressure drop of a cigarette' mean the measured difference in static pressure between the two ends of the cigarette at the fixed flow rate. The pressure drop of a ventilated filter cigarette can be measured either with the ventilation holes of the filter element open, i.e. the unbound cigarette pressure drop or PDO (pressure drop open), or with the ventilation holes closed, i.e. the bound cigarette pressure drop or PDC (pressure drop closed). The device used to carry out this test was a standard industrially recognized Cerulean QTM machine which is known in the art. The average values in the table signify that a centre filled smoking article has lower pressure drop or in other words offers lower draw resistance to the smoker when compared to a conventional cigarette made with the same amount of expanded tobacco (table 2) and clove in the blend (Table 2a). The cigarettes are manufactured in accordance with the process mentioned in Example 1.

Table-2: Illustrates pressure drop/draw effort of cigarette can be changed by adding expanded cut tobacco in the inner core region of the centre filled articles of the present invention

*Reference cigarettes (control sample) contains expanded cut tobacco in the blend. Whereas, centre filled cigarettes in table-2 contains expanded cut tobacco in inner core region.

Calculation:

PDO (reference cigarettes) 56.55
56.55-46.15/56.55 = 18%
PDO (cigarettes of the present invention) 46.15

Inference: Based on the above calculation, it has been demonstrated that the centre filled smoking articles of the present invention has a 18% pressure drop than the cigarettes / smoking articles in the blended form.

Table 2a. Illustrates pressure drop/draw effort of cigarette can be changed by adding clove in the inner core region of the centre filled articles of the present invention

Calculation:

PDO (reference cigarettes) 56.7 56.7-46.75/56.7=17%
PDO (cigarettes of the present invention) 46.75
Inference: Based on the above calculation, it has been demonstrated that the centre filled smoking articles of the present invention has a 17% pressure drop than the cigarettes / smoking articles in the blended form.

Table 2b: Illustrates the pressure drop of the centre-filled articles of the present invention (without any barrier in its inner core) will be lesser than the centre-filled smoking articles with barrier. The inner core contains the expanded cut tobacco.

Calculation:

PDO (reference cigarettes with inner barrier) 71.6 71.6-59.45/71.6=17%
PDO (cigarettes of the present invention, without barrier) 59.45

Inference: Based on the above calculation, it has been demonstrated that the centre filled smoking articles of the present invention has a 17% pressure drop than the centre-filled cigarette articles with barrier.

Example 3: Experiment to demonstrate the uniform distribution of the materials that constitutes inner / core portion and delivery of uniform sensorial profile of the centre-filled combustible articles.

Table 3 (Negative example / failed experiment)
Experiment conducted on centre-filled combustible articles (control samples 1 and 2) with 30wt% of clove to demonstrate whether there is an uniform distribution to deliver uniform sensorial profile.

For the experimental purposes, either the cigarettes are commercially procured which contains clove of 30 wt%. Sufficient cigarettes for each of the control samples were picked and then slit to segregate cloves from tobacco. The total weight, clove weight and tobacco weight were then measured and reported. A subset of the reading is shown in the table below.

Constituents Control sample 1 Control sample 2
Tobacco content Tobacco blend of Virgina 70wt% Tobacco blend of
Burley & Virginia 70 wt%
Clove content 30 30

Inference: The above mentioned table 3 clearly indicates that the variation of clove content (30% in blend) in cigarette to cigarette and also found distribution of clove is not uniform (<22%) which directly reflects on smoke perception and variation within the cigarette.
Table 4 (Positive example of the present invention)

The cigarette composition and the method of preparation are described in example 1.
The above data suggests the when 30 wt % of clove (non-tobacco, aromatic substance) constitutes the inner/core portion and its distribution, sensorial delivery profile is significant (>27% consistency) when compared with the control samples (only 22% consistency, pl. refer table 3).

Figure 5 illustrates that there is no visually perceivable stain or puncture marks on the centre-filled combustible articles of the present invention.

Smoking articles like cigarettes prepared in accordance with the present invention have uniform smoke characteristics, without any perceivable marks like stains (also known as “spotting”) on the finished product (Figure 5), post-use or during-use or while storage, and it does not interfere with the product quality. Also the inner core portion of the centre filled article can be ovoid, elliptical, round, spherical or any of the shape which is substantially circular in shape (figure – 6).