HK1178755A - Reconstituted tobacco sheet and smoking article therefrom - Google Patents

Description

Reconstituted tobacco sheet and smoking article thereof

This application is a divisional application with application number 200580035343.0. The application date of the parent case is 8/4/2005; the invention relates to a regenerated tobacco sheet and a tobacco product thereof.

Cross Reference to Related Applications

This international patent application claims priority to and benefits from U.S. patent application serial No. 10/920,466 in the present application filed 8/18/2004. Patent application 10/920,466, filed on 26.3.2004 as a continuation-in-part of U.S. application serial No. 10/811,270 in the present application, claims priority to and benefits from that patent application, and patent application 10/811,270, continuing on the part of U.S. application serial No. 10/299,231 (now U.S. patent 6,827,087, issued on 7.12.2004) in the present application filed on 19.11.2002, claims priority to and benefits from that patent application, which are incorporated herein by reference.

Technical Field

The present invention relates to a method for producing a reconstituted tobacco sheet, and more particularly, to a method for producing a belt-cast reconstituted tobacco sheet, wherein a gel matrix in the reconstituted tobacco sheet comprises burley tobacco, flue-cured tobacco, oriental tobacco, maryland tobacco, rare exotic tobacco, and combinations thereof. Even more specifically, tobacco sheets having burley tobacco as well as flue-cured tobacco, oriental tobacco, maryland tobacco, rare exotic tobacco, and combinations thereof are cut into discrete inner wrapping strips and the strips are disposed within the wrapper of the tobacco rod. Exotic tobaccos include (but are not limited to): izmar (itazmir) tobacco, Samsun (samson) tobacco, Yaka (hilly land) tobacco, lataikia (lataya) tobacco, Perique (palique) tobacco, Cavendish (suyama) tobacco, Rustica (daylily) tobacco, open Fire cured (Fire-cure) tobacco and Dark (Dark) or Sun-cured (Sun-cure) tobacco.

Background

In the manufacture of smoking articles, particularly cigarettes, it is common to use a percentage of reconstituted tobacco strips in a blend of tobacco strips. Reconstituted tobacco is typically prepared from tobacco dust, veins, stems and other waste tobacco products which are further processed to form sheets, cut into strips, and incorporated into fresh cut tobacco. The amount of reconstituted tobacco used in tobacco blends for smoking articles varies, but is generally less than 20%. Typically, these reconstituted tobacco sheets do not contain additional flavoring compounds, as it has been found that flavoring compounds such as menthol can quickly evaporate or dissipate from the sheets prior to blending with other tobacco, thus having little additional flavoring effect on the tobacco blend.

In addition, there has been much interest in reducing the ignition proclivity characteristics of smoking articles because of the large number of fires that result from burning cigarettes exposed to combustible or combustible substances. Accordingly, considerable effort is expended in the industry to provide smoking articles with low ignition propensity. Many of these proposals include modifying the wrapper of the smoking article. In particular, coatings or additives have been made on the wrapper of a smoking article in order to reduce the porosity of the wrapper or to alter the chemical properties of the wrapper.

Disclosure of Invention

In view of the known deficiencies associated with earlier smoking articles, there has been provided a smoking article having reconstituted tobacco in the form of a discrete inner wrapper strip, the reconstituted tobacco consisting of burley tobacco and a second tobacco, such as flue-cured tobacco, oriental tobacco, maryland tobacco, rare exotic tobacco and combinations thereof. Rare exotic tobaccos may include (but are not limited to): izmar tobacco, Samsun tobacco, Yaka tobacco, Latakia tobacco, Cavendish tobacco, Rustica tobacco, open fire cured tobacco and dark or sun cured tobacco. While the separated inner wrap strips make up less than 9% of the total tobacco strip blend, they impart better smoke flavor, reduce ignition propensity, and increase puff count.

An object of the present invention is to provide a novel formulation for a belt-cast reconstituted tobacco sheet and a method for manufacturing the same.

It is an object of the present invention to provide a reconstituted sheet made from rare exotic tobacco that is used in limited amounts but provides a unique smoke flavor.

It is a further object of the present invention to provide a smoking article comprising a novel belt cast reconstituted tobacco sheet in one layer of the wrapper of the smoking article.

It is an object of the present invention to provide a smoking article comprising a burley bias reconstituted tobacco sheet which provides better tobacco smoke characteristics while minimizing the formation of TSNAs.

The present invention provides a cast strip tobacco sheet that may include about 30% to about 80% by weight of a tobacco blend, about 5% to about 40% by weight of wood pulp, about 8% to about 40% by weight of a binder, and up to about 30% by weight of a flavoring compound such as menthol. The tobacco blend is comprised of at least about 30 weight percent burley and up to about 30 weight percent of a second tobacco. The binder may be alginate (such as sodium alginate), guar gum, gum tragacanth, gum acacia, pectin, other gums, modified cellulose compounds and hydrocolloid compounds. The cast strand tobacco sheet may also include about 8% to about 30% by weight of a humectant, such as glycerin or propylene glycol.

The present invention also provides a method of making a bandcast tobacco sheet comprising a first step of preparing a slurry comprising tobacco, wood pulp, binder and menthol. The prepared slurry is cast onto a moving belt or wire mesh, followed by drying, to form a reconstituted tobacco sheet. The resulting tobacco sheet is cut into lengths having a predetermined width for use in smoking articles. In one embodiment, the strips are disposed longitudinally along the tobacco rod between the tobacco rod and the outer wrapper of the cigarette or smoking article.

In the preparation of the belt casting compound, wood pulp and a binder (particularly an alginate such as sodium alginate) are added to increase the strength of the sheet and to bind the ingredients into the tobacco sheet. To increase the flexibility of the flakes, a humectant such as glycerin may be added, in addition to any desired flavoring such as menthol and other fillers such as calcium carbonate. The proportions of the materials vary from one material to the next depending on the end use. However, in the preferred sheet, the amount of tobacco in the mixture is generally about the same as the binder such as sodium alginate, but the tobacco may be 10-20% by weight more than alginate.

The present invention also provides a cast strip tobacco sheet having both burley tobacco and a second tobacco, such as flue-cured tobacco, oriental tobacco, maryland tobacco, or rare exotic tobacco, and combinations thereof, and a method of making the same. Rare exotic tobaccos include (but are not limited to): izmar tobacco, Samsun tobacco, Yaka tobacco, Latakia tobacco, Perique tobacco, Cavendish tobacco, Rustica tobacco, open fire cured tobacco and dark or sun cured tobacco.

Because of the high content of Tobacco Specific Nitrosamines (TSNAs), such as burley tobacco, the content of burley inclusions in potentially reduced exposure products is limited to less than the normal 25% -40% inclusion content for american hybrid cigarettes. Using less burley than normal results in a less balanced tobacco smoke profile. By separate inner packaging techniques, TSNA formation or transport in the smoke is minimized. This technique involves the use of one or more ribbed or ribbed skewed reconstituted tobacco sheet strips immediately inside the cigarette wrapper, which strips are aligned longitudinally along the tobacco column of the cigarette and are adjacent to each other on the periphery of the tobacco column.

The use of a separate inner wrapping strip of burley-type slip cast reconstituted tobacco provides unique properties to the cigarette such as reduced ignition propensity, improved smoke flavor, and increased cigarette puff count while minimizing TSNA levels. As for the organoleptic improvements, most of the smoke products formed should be transmitted to the mainstream smoke as combustion occurs preferentially toward the periphery or surface of the rod. Because the combustion temperature of a cigarette is generally lower on the outside of the rod and higher in the core, positioning the separate inner band on the outside enables it to produce less chemical compounds than the tobacco in the core, and thus the separate inner package contributes less to the Huffman Analyte (HA) emissions in the mainstream smoke. Thus, by using burley tobacco to make a split inner wrap strip of reconstituted tobacco for insertion into a tobacco rod, the smoke characteristics of the burley are improved, the taste impact is optimized, and mainstream huffman analyte emissions are minimized.

The invention also provides a smoking article comprising a split inner wrapper strip of burley reconstituted tobacco. The split inner package may be manufactured by belt casting, paper making, or extruded reconstituted tobacco techniques. It is noted that the present invention also provides a split inner wrap strip made from burley and flue-cured, oriental, maryland tobacco or combinations thereof together, wherein an outer layer and a flavoring may optionally be added. Moreover, certain rare exotic delicious tobaccos (e.g., Izmar tobacco, Samsun tobacco, Yaka tobacco, Latakia tobacco, Perique tobacco, Cavendish tobacco, Rustica tobacco, open fire cured tobacco, and dark or sun cured tobacco) can also be used in amounts less than those used in commercial applications.

Additional objects and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description, including examples of manufacture of the band cast reconstituted tobacco sheet of the present invention.

Drawings

FIG. 1 is a partial perspective view of a cigarette of the present invention utilizing reconstituted tobacco strip cast sheets of the present invention;

FIG. 2 is a perspective view of an expanded cigarette wrapper comprising a strip of belt cast reconstituted tobacco sheet of the present invention;

figure 3 is an end view of the cigarette of figure 1;

FIG. 4 is a perspective view of a cigarette wrapper of the present invention comprising a strip of belt cast reconstituted tobacco sheet;

figure 5 is a partial perspective view of a cigarette of the present invention comprising a plurality of strips of belt cast reconstituted tobacco sheet;

Detailed Description

A cigarette with burn rate modification is shown in figure 1 and may be described as a partial double wrapped cigarette 10. The tobacco can be burley tobacco, smoked tobacco, oriental tobacco, maryland tobacco, rare exotic tobacco, and combinations thereof. As can be seen, the partial double wrapped cigarette 10 of the present invention comprises a standard tobacco column 13 extending from an exposed end to a filter 15. Surrounding the tobacco column 13 is an outer wrap of cigarette paper 12. Inside the overwrapped cigarette paper 12 are separate partial inner overwrap layers or bands 14a and 14 b. The discrete partial inner wrappers 14a and 14b act as burn rate modifiers for the tobacco column 13 by modifying the burn characteristics of the cigarette 10. As can be seen from the embodiment shown in figure 1, the strip of inner wrapper may be coaxial with the tobacco column 13 and may extend substantially the length of the tobacco column from the exposed end to the filter 15. By inserting the discrete partial inner wrappers 14a and 14b extending coaxially with the tobacco column 13 in this embodiment, it is possible to employ a structure that makes it possible to make the width, inner side, of the discrete partial inner wrappers 14a and 14b according to the packing density of the tobacco, the porosity of the outer wrapper 12 and the additives in the outer wrapper, and the width of the discrete partial inner wrappers 14a and 14b

The porosity of the wrapper layers 14a and 14b and the manner in which the additives in the inner wrapper strip adjust the burn rate improve the burn rate of the cigarette. Alternatively, the inner wrapper may be shortened to not extend the entire length of the tobacco column 13, or may extend in a different direction. Accordingly, many variations in the burn rate of the partial double wrapped cigarette 10 of the present invention may be made based on a combination of factors described herein.

As shown in figure 1, the partial double wrap cigarette 10 of the present invention having improved burn rate characteristics comprises an outer wrapper 12 having discrete first and second partial inner wrapper strips 14a and 14b of the outer wrapper 12. The overwrap cigarette paper 12 may be normal porosity paper exhibiting a porosity of 15-80CORESTA units (cigarette paper air permeability units). At least one partial inner wrapper layer that modifies the burn rate characteristics of the cigarette 10 is disposed in combination with the outer wrapper cigarette paper 12. As shown, first and second partial inner wrappers 14a and 14b are disposed on opposite sides of the tobacco column 13. In order to provide substantially equal burn rate characteristics along the entire tobacco column 13, the partial inner wrap strips 14a and 14b may extend substantially coaxially with the tobacco column 13 to the filter 15.

As shown in the embodiment of fig. 4, the partial inner wrappers 14a and 14b extend from one end of the tobacco column 13 to the other and may be positioned so that they are equidistant from each other or they may be placed in alternating positions depending on the burn rate characteristics desired.

Turning to figure 3, it is apparent that the partial double-wrapped cigarette 10 of the invention has alternating high diffusion areas 21 and low diffusion areas 22 depending on the placement of the inner wrap layers or strips 14a and 14 b. It can be seen that at least one of the high diffusion areas 21 allows enhanced permeation of CO and oxygen through the barrier formed by the overpack 12 while maintaining normal emissions. In conjunction with this, the low diffusion regions 22 defined by the circumferential extent of each of the partial inner wrapper layers 14a and 14b can potentially block a substantial portion or all of the gas ingress and egress, which is directly related to the combined porosity of the inner wrapper layers 14a and 14b and the outer wrapper layer 12. In the linearly corresponding regions of the high diffusion region 21 and the low diffusion region 22, the porosity of the linearly corresponding high diffusion region may be greater than 14CORESTA units, and the porosity of the linearly corresponding low diffusion region may be less than 8CORESTA units.

As shown in the drawings, the construction of the cigarette with burn rate modification is a partial double wrapped cigarette 10 as depicted herein and utilizes a standard overwrap cigarette paper 12, which in a typical cigarette is 27mm in width. In an alternative embodiment, shown in FIGS. 2 and 4, disposed along the interior of the overpack are separate partial inner wrap layers 14a and 14b, which may extend substantially along the length of the overpack 12. Although the outer wrap of the cigarette paper may be of standard porosity and construction, the partial inner wrap in this embodiment has first and second bands 14a and 14b, each of which may be 4mm in width and may have a porosity of less than 8CORESTA units. Thus, in combination, the two inner wrappers or strips 14a and 14b may circumscribe about 8mm of the circumference of the partial double wrapped cigarette 10 of the present invention, but for standard cigarette sizes, the two inner wrappers or strips 14a and 14b may also extend around up to 15mm of the circumference of the tobacco column. Any combination of partial inner and outer wrappers may function in accordance with such variables as the porosity of each of the wrappers, but we believe that good burn rate characteristics and limited impact on smoke characteristics and taste may be achieved by incorporating an inner wrapper that covers less than about 75%, or preferably less than about 60%, and even more preferably less than about 35%, of the circumference of the outer wrapper. The above values are a function of the whole cigarette and may vary with the circumference of the overwrapping. However, with the inventive aspects of the present design, variations may be utilized to achieve the same advantageous results and these descriptions are not to be considered limiting of the invention, which is merely illustrative. Additionally, even though two straps are shown, it should be appreciated that multiple straps may be used, if desired.

Alternatively, many different configurations may be utilized to provide the cigarette with burn rate modification described herein. It will be appreciated that a single inner wrapper or multiple inner wrappers may be provided depending on the desired characteristics and burn rate modification. Thus, as previously described, a combination of low porosity inner and higher porosity outer packing sections may be utilized to provide various linear burn rates that may be desired. Thus, a typical linear burn rate of 6.0 mm/min can be reduced, if desired, based on a combination of the porosities of the outer and partial inner wrapper strips, and it can also be easily reduced to below 4 mm/min, if desired. This includes designing a single inner packaging strip with lower porosity or replacing the inner packaging strip with various materials of construction including reconstituted tobacco, low porosity paper, bandcast tobacco, polymer based materials, other papers or materials. The inner wrap strip may be coated with a burn modifier or other material that will form at least one low diffusion zone along the tobacco column. For example, the cigarette paper may be coated with the burn inhibitor sodium alginate to reduce the porosity of the cigarette paper and provide sufficient characteristics such that the overall combination of outer package porosity, tobacco packing density, the number of inner package circumferences and bands covered, inner package porosity and other factors enable the cigarette to exhibit a desired burn rate.

As shown in fig. 4-7, various embodiments may be utilized to form the low porosity region. As shown in fig. 4, the opened standard overpack 12 is lined with a plurality of inner wrap or inner layer strips 16a, 16b, 16c, and 16 d. The bands may be spaced equidistantly along the interior of the overwrap 12 and positioned away from the edges or seams that bond the overwrap together during rolling in the bottom of the cigarette rod (garniture) of the cigarette making machine. As shown, all of the strips 16a-16d may be fed into the bottom of the smoker and incorporated on the inside of the outer wrap adjacent the tobacco column. The placement of the partial inner wrap strip modifies the burn rate to a desired level so that the burn rate can be reduced sufficiently to cause a significantly reduced static burn rate or self-extinguishes within a desired interval.

As shown in fig. 5, an inner layer having non-linear side edges 17 compared to the edges of the outer package 12 may be utilized as a partial inner package to form the low porosity zone. As shown, the inner wrap 17 may be corrugated such that the placement of the low porosity zone varies in location along the tobacco column axis. This non-linear arrangement of the low porosity zone may allow the cigarette to be arranged differently during static combustion and may ensure that the required static burn rate is effective regardless of the location of the cigarette.

Another embodiment of a cigarette with burn rate modification of the present invention is depicted in figure 6. As can be seen, by adding a partial double wrap inner wrap layer 18 surrounding a portion of the tobacco column 13 on the inside of the outer wrap 12, a high diffusion region 21 and a low diffusion region 22 are defined. As shown, the partial inner wrapper 18 extends about halfway around the circumference of the tobacco column 13. However, many different configurations may be utilized to achieve a suitable linear burn rate through the burn rate modification described above. The partial double wrap inner wrapper 18 may consist of standard cigarette paper having a low porosity of less than 7CORESTA units or cigarette paper coated with burn rate modifiers, or it may be an alternative construction such as a bandcast tobacco sheet with or without additives, which typically has a low CORESTA unit value, which is typically less than 5, more preferably less than 3. A second advantage of using a bandcast or reconstituted tobacco sheet as the partial double wrap inner wrapper layer 18 is that the coloration of the inner wrapper may be such that it resembles the tobacco column 13 and does not provide a relatively whitened area extending along the low diffusion areas 22. Alternatively, a polymeric film or other material may be used as the partial double wrap inner wrapper 18. The width of the inner layer of the partial double wrap shown in figure 6 is preferably 2-14mm, or less than 75% of the circumference of the outer wrap, in order to obtain the desired suitable burn rate modification, wherein the linear burn rate is maintained at a sufficiently low level, preferably below 4.0 mm/min.

As shown in FIG. 7, an alternative embodiment is disclosed wherein a plurality of inner wrap strips 19 are utilized, the strips 19 generally surrounding the tobacco column 13 on the interior of the outer wrap 12. These inner wrap strips 19 may be fed into the bottom of the cigarette rod adjacent the outer wrap 12 and surround the tobacco column 13 as the tobacco column 13 is formed in the cigarette making machine. These bands 19 may consist of low porosity cigarette paper fed into the cigarette making machine individually or of a single or multiple bands fed into the cigarette making machine adjacent the bottom of the cigarette gun and cut to the appropriate band width. As shown in fig. 7, a plurality of inner wrapping strips 19 are utilized, the strips 19 extending substantially coaxially along the length of the tobacco column 13. Preferably, these strips 19 extend along the entire tobacco column length to modify the burn rate along the entire tobacco column regardless of the cigarette arrangement. It is believed that by providing a plurality of bands 19 as shown in figure 7, a more even improvement in the burn rate of the cigarette can be made.

It will be appreciated that by extending the inner wrap layer substantially along the length of the tobacco column 13 so that they are coaxial, a significant advantage is provided over alternating rings perpendicular to the axis of the tobacco column 13. Such vertical rings alternating along the length of the tobacco column may provide a non-linear burn rate of the tobacco column 13. Thus, in such a design having a surrounding ring around the tobacco column, the linear burn rate can be varied between a low linear burn rate and a high linear burn rate depending on the ratio of the porosity of the paper at the point where the ring is located to the porosity of the unadjusted paper between the rings. In practice, such non-linear burn rates are not good because the tobacco column between the rings continues to burn freely for a significant period of time and does not produce a suitable burn rate modification that can be relied upon throughout the length of the tobacco column. In addition, where a low porosity ring is present, the smoker can smoke the cigarette when the tobacco column is not burning on the low porosity ring. At this point, we believe that the cigarette emissions may change significantly, increasing CO and other compounds as long as the cigarette burns in one of these rings. The partial double wrap inner layer of the present invention thus overcomes these problems by providing known standard emissions over the entire length of the tobacco column, while improving burn rate along the entire coaxial length.

In the design of the cigarette with burn rate modification 10 of the present invention, it may be desirable to incorporate an inner wrap layer, whether multiple strips or a single layer, at a location remote from the seam of the outer wrap 12. As is known in cigarette manufacture, the seam 23 as shown in figure 1 is formed by the cigarette maker overlying the side edge 24 of the outer wrapper 12. In typical cigarette manufacture, adhesive is applied along one of the edges 24 prior to rolling the overwrap and forming the tobacco column 13. In the manufacture of the cigarette with burn rate modification 10 of the present invention, it is desirable to maintain the partial inner wrapper layer at a location remote from the seam portion in order to ensure that the outer wrapper 12 is properly formed and that the partial inner wrapper layer does not interfere with the formation of the tobacco column or the adhesive of the outer wrapper layer. Thus, as depicted in these embodiments, the partial inner wrap layer is shown disposed away from the side edges 24 so that the inner wrap portions do not interfere with neither the seam of the outer wrap 12 nor the formation of the tobacco column within the bottom panel of the smoker in a typical cigarette making machine. Thus, the cigarette with burn rate modification of the present invention can be implemented on a standard cigarette making machine, with only minor modifications to the paper feed and therefore without any modifications to the bottom plate of the cigarette gun. It will also be apparent that in any of the embodiments shown herein, the strips may be alternately disposed on the exterior of the cigarette and retained on the wrapper by adhesive or other means such that linear corresponding zones of high and low porosity are still formed.

As shown in fig. 8, a simple design for making a cigarette with burn rate modification as described herein is depicted. The paper feeding apparatus 50 includes two sources of paper, an outer package bobbin 37 and an inner package or strip bobbin 32. Overwrap bobbin 37 may be comprised of standard porosity overwrap cigarette paper having a standard width which may vary, as is typical, between 19-27mm, and the paper may be fed into the cigarette maker by a plurality of rollers and tension rails. In the illustrated embodiment, the partial inner and outer wrap layers may be combined to form a combined cigarette paper 36, wherein the outer and inner wrap layers receive tobacco within the base of the cigarette gun. The outer wrapper 30 may be located below partial inner wrapper strips 34, 35 fed from a bobbin 32 of inner wrapper strips or other source. The inner wrap strip bobbin 32 may be narrower than the outer wrap because it is desired to cover only a portion of the inner surface of the outer wrap 30. The inner wrap strip bobbin 32 may be unwound, fed through a roll, and cut with a knife into the desired strips, and then formed into a combined cigarette paper 36 just prior to the bottom panel of the cigarette gun. The bands 34, 35 forming the inner package portion of the cigarette of the present invention may have burn rate characteristics that are significantly different from those of the outer package 30. Thus, by providing a double bobbin on the machine, designated 50 in this embodiment, variations in porosity, content and other characteristics can be provided. A shear 33 may be provided to shear the inner wrapper into two or more strips.

As shown in fig. 8, the inner package tape bobbin 32 may have a paper having a width of 4-15mm, which is cut into two tapes. The correct combination of porosity and burn characteristics of the inner and outer wrappers can be adjusted to produce the appropriate burn rate modification required to produce a standard linear burn rate for the cigarette and tobacco column as a whole.

As shown in fig. 8, the disclosed paper feeding apparatus 50 includes a plurality of tension rollers for sufficiently feeding the outer wrap 30 and the partial inner wrap strips 34, 35 to make the combined cigarette wrapper 36. It will be appreciated that the smaller the width of the bobbin 32, the more problems arise in feeding the cut paper to the base of the cigarette gun. The straps 34, 35 must be tightened sufficiently to prevent the inner wrap straps 34, 35 from rupturing prior to entering the bottom panel of the pipe. In addition, because the cigarette manufacturing process is essentially a stop-and-go process, the outer package bobbin 37 and the inner package strip bobbin 32 must be properly pulled tight. Thus, the partial inner wrapper strips 34, 35 may be combined with the outer wrapper 30 just prior to entering the bottom panel of the pipe, or immediately after cutting as shown in figure 8, to properly tension and combine the two layers.

Turning to fig. 9, a cross-section of a bottom plate of a smoking gun within a cigarette making machine is shown. The bottom panel 40 is the area within the cigarette maker where the cigarettes are rolled and formed. There is typically a belt between the outer wrap 30 and the bottom panel 40 of the smoker, but the belt is not shown herein for illustrative purposes. As shown, the bottom panel 40 of the smoker has a curved surface for forming a tobacco column and cigarette. After the tobacco is stacked by the tobacco supplier 41 in the cigarette making machine, the curved surface winds the outer package 30 around the tobacco. The inner wrap strips 34, 35 are engaged with the outer wrap 30 prior to entry into the bottom panel of the smoker so as to wind up the combined cigarette wrapper 36 and form tobacco therein when the cigarette wrapper has been properly formed. This design provides flexibility in combining various characteristics of the outer wrapper and the partial inner wrapper. Another advantage of the in-line formation and treatment of the cigarette with burn rate modification of the present invention is that it is an in-line process that does not affect the speed or formation of the actual cigarette. Thus, within the bottom panel of the cigarette rod, no significant modification need be made in forming the rod, cutting the rod to the appropriate length, and then adding it to the filter at a later point on the cigarette making machine.

As shown in figure 9, the inner wrap strips 34, 35 on the inner surface of the outer wrap 30 are fed into the bottom of the cigarette gun so that they are in place as the cigarette making machine forms the cigarettes and tobacco column. In this example, as shown in figure 3, the inner wrap strips 34, 35 are disposed at 90 ° to the seam of the outer wrap 30, and the inner wrap strips 34, 35 may be placed equidistant from each other to provide a smooth and continuous burn rate modification for the cigarettes. Preferably, no adhesive is used to place the inner wrapper on the inside of the outer wrapper 30, but other position maintaining materials may be used. The placement of the inner wrap strips 34, 35 is maintained both by the formation of the cigarettes in the bottom panel 40 of the garniture and by the compaction of the tobacco into a rod.

Turning to fig. 10, an alternative embodiment 82 of a paper feeding apparatus is shown. In this embodiment, the outer wrap 12 is fed from a standard position to a bullet roller 57, which bullet roller 57 directs the cigarette wrapping material to the bottom plate 60 of the cigarette gun for forming the cigarettes. In this example, the overwrap 12 may be standard cigarette paper 27mm wide and may have normal porosity and other typical additives. As shown, the combined partial double wrap 36 is formed by the combination of the outer wrap 12 and the two-line inner wrap strips 34, 35, which may be combined prior to the base of the cigarette gun.

As can be seen, the inner wrapping strip paper 32 from the bobbin is fed to the guide roller 58 and then cut or sheared by the cutter 51. The rotary cutter may be composed of a rotary cutter 52 and a cutter frame 53. In this formation, the interior of the cigarette is required to have an 8mm wide combined section covered with partial double inner wrap, and the inner wrap 32 may be provided cut in half to form equal 4mm wide strips 34, 35. These strips may be formed by a slitter 51 and separated by separating rollers 55, 56 and then combining the partial inner wrapper strips 34, 35 with the outer wrapper 12 at a roller 57. Of course, the inner package 32 could also be cut into even narrower strips for laying over the outer package.

One advantage of this design is that a slitter 51 can be provided to cut the paper to the desired width. A problem with feeding narrow strips and thus making guide and tension rollers a necessity is that care must be taken to prevent the inner wrapper 32 and the respective strips 34, 35 from being broken after the narrower strips are formed. Therefore, it is advantageous to provide the rotary cutter 51 in close proximity or adjacent to the bottom 60 of the garniture to prevent excessively long feeding of the narrow inner wrapping strips 34, 35.

In the paper feeding apparatus 82 as shown in fig. 10, a slitter 51 is shown for forming the strips 34, 35 from the original web 32. In all of these embodiments, many different cutting devices or shears may be used, such as static knives, lasers, rotary knives as described above, water jet cutters, kiss-cuts, or micro-hole formation. Alternatively, a pre-manufactured web may be provided, pre-cut into individual strips, which may then be separated and subsequently fed into the bottom of the pipe by various conveyors. Many different embodiments may be utilized to combine a suitable inner wrap strip with an outer wrap into the bottom panel of the pipe. Although several embodiments disclosed herein teach specific structures to accomplish the feeding of the inner wrap strip to the bottom of the smoker, many embodiments may be provided to form or combine the inner wrap strip with the outer wrap to the bottom of the smoker. Such variations are considered to fall within the teachings of the present application and no unnecessary limitations are to be drawn from the specific examples of sheet feeding apparatus described herein.

As disclosed in fig. 11, an additional embodiment 84 is provided wherein the cigarette maker 74 may have an external bobbin unit 70, 71. The outer bobbin unit 70 may have a bobbin 30, the bobbin 30 providing an outer wrapper to be fed into the bottom plate 77 of the smoking barrel. A bobbin 30 provides the web 12, and the web 12 is fed into the bottom of the smoker and combined with a web 32 forming the inner wrapper strip. The external bobbin unit 71 may have a bobbin of material 32 fed into a knife mechanism 75 for cutting. A shear or cutting mechanism 75 is positioned immediately adjacent the bottom plate 77 of the pipe to reduce the length of the individual narrow inner wrapping strips being fed. As shown, the cigarette making machine 74 has a garniture bottom 77 and a garniture bottom belt 78 driven by a drive shaft 73, the belt 78 feeding paper and tobacco material through the garniture bottom during cigarette formation to form a tobacco rod and cigarette in which an inner wrap strip is formed.

It will be appreciated that the provision of the outer bobbin units 70, 71 of outer and inner wrapper allows for easier on-line handling of the cigarette paper and provides for the incorporation of the partial inner wrapper bands into the cigarette making machine 74. In addition, the provision of the outer wrap bobbin 30 and the inner wrap bobbin 32 externally requires minor changes to the structure of the cigarette maker 74, as these bobbins are separate from the cigarette maker 74 without any significant changes to the area around the bottom plate 77 of the cigarette gun other than the guide rollers and tension rollers. In addition, outer bobbin units are currently implemented with cigarette making machines and are provided to combine the outer and partially inner wrapping bands of the present invention together to form the appropriate burn rate modification required.

In use, the outer unit 71 may be fitted with a spool of tape slip cast material rather than a standard cigarette wrapper bobbin. The bobbin may be used because the material of the belt casting has unevenness. A bobbin having a strand cast recombinant band may be used wherein the width of the material is 8mm and the material is fed into the cigarette maker 74 by guide rollers as the bobbin is unwound to minimize movement of the strand cast material. The material may be joined to the outer wrapper immediately after the material is cut on a bullet roller, which is typically the roller located in the first or beginning portion of the base of the cigarette gun. A plurality of guide rollers and tension rollers may be provided for properly feeding the material to the bottom plate of the smoking gun and combining the material with the outer wrapper.

Variations in the characteristics of the outer wrapper and the inner wrapper can be used to design a cigarette with burn rate modification of the present invention. As previously mentioned, standard overpack designs are such that a typical overpack has a linear layout width of 27mm, and generally has a porosity of between 15 and 80COREST units. It is well known that significant reductions in overwrap porosity can alter cigarette emissions and linear burn rates. By adding a partial inner wrap to a cigarette, improvements can be made to the standard burn rate of a normal or typical cigarette. The partial inner package may be a single inner package portion or may be a plurality of inner package strips as shown in the various figures. The partial inner wrapper may have a paper property with a significantly reduced porosity such that the inner wrapper paper exhibits a porosity of less than 8CORESTA units. If a single inner package strip is utilized, such as tape casting or other paper as previously described and depicted in FIG. 6, the width of the inner package layer may be between 2-15 mm. The porosity of the inner wrapper can be adjusted from any value to 0-8CORESTA units.

Examples of the invention

Several examples of products employing partial strip wrap or partial inner wrap cigarette constructions utilizing the inventive techniques and constructions described herein are listed below. In these examples, a control cigarette without a partial inner wrapping strip was used, which had a linear burn rate of between 4.3 and 4.7 mm/min. As detailed in the table below, different materials were used as the partial inner wrapping bands, ranging from standard treated paper to bandcast tobacco materials.

An example of a cigarette having two belt cast inner wrap strips, wherein the belt cast material has a porosity of less than 5CORESTA units:

an example of a cigarette having two cigarette paper strips, wherein the two cigarette paper strips are treated or covered with sodium alginate and the porosity of the inner strip paper is less than 5CORESTA units:

two examples of cigarettes detailing smoke emissions for samples with belt cast strips:

in the examples given, it is evident that increasing the local inner package in the cigarette has a clear effect on the linear burn rate and self-extinguishment compared to the control cigarette. The linear burn rate using the cigarette of the present invention was directly affected and proved to be reduced up to 40%. All test specimens self-extinguish when using an inner packaging tape with a width of at least 4 mm. Narrower width strips have different results and can be modified by using alternative additives or increasing the number of strips. For the automatic extinguishment of cigarettes, it is related to the NIST test which uses 10 layers of filter paper for flammability testing.

Smoking article comprising a band-cast reconstituted tobacco strip

The discrete partial inner wrap strip 14 may be a strip cast reconstituted tobacco strip manufactured according to a particular formulation and method of manufacture thereof as will be discussed below. The overwrap cigarette paper 12 may be normal porosity paper that typically exhibits a porosity of 15-80CORESTA units. As shown, two strips 14 of reconstituted tobacco sheet are provided on opposite sides of the tobacco column 13 so as to provide a partial inner wrapper. The partial inner wrap comprising the reconstituted tobacco strip 14 may extend substantially the length of the tobacco column 13 and may be coaxial with the tobacco column 13. In one embodiment, the bands are disposed equidistant from one another to provide for uniform combustion of the resulting cigarette.

Manufacture of belt type cast reconstituted tobacco sheet

In the manufacture of bandcast reconstituted tobacco sheet for use in cigarettes, wood pulp, a binder such as sodium alginate and ground tobacco particles or concentrated extracts are slowly added to a tank containing water and mixed under high shear while adding the materials to ensure that each component is adequately dissolved or dispersed in the slurry. Specifically, it is desirable to add the wood pulp, tobacco, and then alginate in that order. To increase the flexibility of the flakes, glycerin may also be added, typically after the alginate and before any additional flavoring agents. In addition, in the preferred slurry, desirable flavors may also be added, one particularly desirable flavor being menthol. An intervening filler such as calcium carbonate may also be added to the slurry. It has been found that the ratio of tobacco to alginate is preferably about 4.0: 1.0 in order to obtain a sheet with a tensile strength sufficient to withstand the forces of a cigarette making machine. The resulting slurry is thinly spread on a casting surface such as a stainless steel belt heated to about 200 ° F. The slurry coating remains on the heated belt until the resulting sheet is sufficiently dry to be removed from the belt intact. The resulting cast strip flakes can be used immediately or can be conditioned at 100 ° F, low humidity for 24 hours or more to further "encapsulate" any flavor additives such as menthol. The sheet may then be shredded and added to the tobacco blend, or cut into elongate strips of the desired width and used as strips extending longitudinally along the outer periphery of the tobacco rod and the inner surface of the outer paper wrapper. Smoking articles utilizing these reconstituted tobacco inner strips containing menthol retain their minty taste for a considerable period of up to 1 month when the package is opened. In sealed packages, their minty taste is retained for at least 4 months.

In one embodiment, the tobacco blend comprises 30-80% by weight; wood pulp comprises about 5-40% by weight; the adhesive accounts for 8-40% by weight; if a flavoring such as menthol is added, the flavoring is up to 30% by weight. Preferably, the tobacco is present at about 26% by weight, the wood pulp at about 13.5% by weight, the binder at about 27% by weight, and the menthol at about 20% by weight. The total mixture (i.e., the solids mixture) comprises about 2 weight percent to about 10 weight percent of the slurry formulation. The binder may be alginate (such as sodium alginate), guar gum, gum tragacanth, gum acacia, pectin, other gums, modified cellulose compounds and hydrocolloid compounds. A humectant, which may be glycerin or propylene glycol, may be added. The tobacco blend may be comprised of at least about 30 weight percent burley and up to about 30 weight percent of a second tobacco. The second tobacco type can be a flue-cured tobacco type, a maryland tobacco type, a exotic tobacco type, and combinations thereof. Exotic tobaccos include (but are not limited to): izmar tobacco, Samsun tobacco, Yaka tobacco, Latakia tobacco, Perique tobacco, Cavendish tobacco, Rustica tobacco, open fire cured tobacco and dark or sun cured tobacco.

The present invention may be more fully understood by consideration of the following examples. It should be understood, however, that these examples are not intended to unduly limit this invention.

The following example demonstrates the procedure followed in the manufacture of a bandcast reconstituted tobacco sheet for use in smoking articles.

Example 1

In the manufacture of bandcast reconstituted tobacco sheet, 130 gallons of water was poured into a first vessel having a high shear mixer therein. While stirring the water, 35 pounds of wood pulp was added and thoroughly dispersed, 70 pounds of tobacco was added and thoroughly dispersed, 70 pounds of sodium alginate was added and thoroughly dispersed, and 35 pounds of glycerin was added and thoroughly dispersed. In a separate tank, 52.5 pounds of menthol was added to 15 gallons of water at 40 ℃; the mixture was stirred until the menthol dissolved. The resulting mixture was added to the alginate slurry and allowed to fully disperse. More water is added to bring the viscosity between 10000 and 20000 cps, preferably 15000 cps, to ensure correct casting.

The slurry was then cast onto a stainless steel belt maintained at a temperature of about 200 ° F to a thickness of about 40-60 mils. The flakes remained on the stainless steel strip until dry, which took approximately 6-8 minutes. The resulting menthol-treated cast strip lamina is left in lamina form until cut into strips for use in smoking articles.

It has been found that elongate smoking articles provided with a cast strip reconstituted sheet between the paper wrapper and the outer surface of the tobacco rod are able to retain their minty taste for 1 month in the open package. The minty taste of these smoking articles can be retained for at least 4 months, and possibly up to 1 year, in a sealed package.

It will be appreciated that the invention is not limited to the specific examples shown, as the parameters described in the examples may be varied by appropriate variation of the amounts of the components within the reconstituted bandcast tobacco sheet blend used in the examples.

Manufacture of ribbed reconstituted tobacco sheet and separated inner packaging strip

In general, the manufacture of the ribbed belt cast reconstituted tobacco sheet and the discrete inner wrapping strip follows the manufacture of the belt cast reconstituted tobacco sheet and the discrete inner wrapping strip as described above, with minor modifications. Note that burley and the second tobacco type are present in the tobacco blend. The first tobacco is preferably burley which comprises at least about 30 weight percent of the tobacco blend, and the second tobacco, such as flue-cured tobacco, oriental tobacco, maryland tobacco, rare exotic tobacco, and combinations thereof, comprises up to about 30 weight percent of the tobacco blend. Exotic tobaccos include (but are not limited to): izmar tobacco, Sumsun tobacco, Yaka tobacco, Latakia tobacco, Perique tobacco, Cavendish tobacco, Rustica tobacco, open fire cured tobacco and dark or sun cured tobacco.

Example 2

In the manufacture of reconstituted tobacco sheets, tobacco dust, tobacco veins, tobacco stems, tobacco scraps, cut tobacco, shredded tobacco or combinations thereof are mixed with an aqueous solvent. The starting material comprises between about 30% and 100% by weight burley tobacco. 1 part of tobacco was added to 11-20 parts of aqueous solvent and extracted at 160F (70℃) for 30 minutes. The mixture is separated by centrifugation, filtration or extrusion into a water soluble extract and a solid/fiber water insoluble component.

The extract is concentrated by vacuum evaporation, or the extract is freeze-dried, a humectant such as glycerin is added, and they are mixed together thoroughly. The extract may optionally be treated with an adsorbent to selectively remove undesirable components such as TSNA, polyphenols and proteins, and then centrifuged. The adsorbent was discarded, the remaining extract was concentrated, and it was mixed with the humectant. An alginate binder may then be added to the extract.

The solid/fiber component is refined and mixed with more than 10% of the wood fibers that have been refined to pulp in a previous process. Then, a sheet is manufactured by a paper making process using the fiber/pulp mixture. The extract prepared as described above was reapplied to the sheet. The sheet is cut and wound onto a bobbin to form a discrete inner wrapping strip of burley reconstituted tobacco.

Another sheet manufacturing option of the present invention can be obtained after considering the following example. It should be understood, however, that these examples are not intended to unduly limit this invention. The following example demonstrates the procedure followed in the manufacture of a burley belt cast reconstituted tobacco sheet for use in smoking articles.

Example 3

As shown in the following formula table, 1 part tobacco and other solids were mixed into 10-11 parts water to produce belt cast reconstituted tobacco:

^acarboxymethyl cellulose from TIC Gums (15K)

^bKelvis from ISP Alginates co

^cThe cooking releases gum, thereby forming a stronger tobacco sheet and reducing the amount of binder required

The solids and water were mixed successively in the following order: the water, tobacco and wood pulp were mixed thoroughly for 10 minutes. The binder (CMC and sodium alginate) and the remaining part of the water were mixed separately for 10 minutes and then added to the water/tobacco/pulp mixture. Subsequently, glycerol was added and mixed for a further 10 minutes. The mixture was then cast as a continuous sheet on a moving steel belt, passed through a drying tunnel, conditioned to 10-12% moisture and finally wound onto a bobbin. The sheet on the bobbin was then cut into 8mm wide spools and wound laterally on another bobbin. A commercial blend of strips containing 35% white ribs was used to make control cigarette samples without a regenerated inner wrapper strip of white ribs. Test cigarettes were manufactured by regenerating the inner wrapping strip with white ribs using a similar blend of strips containing 15% white ribs. For the test samples, each 8mm reconstituted tobacco bobbin was further spliced into two 4mm bobbins in half, which were then fed into the cigarette making machine. Each finished cigarette contains 2 inserts of 2 x 4mm, which are located adjacent to each other on the periphery of the tobacco section of the rod in the cigarette paper. Other belt casting variants, Exotic I, Exotic II and Exotic iii, were produced in a similar way as described above, except that each of them (see the above formula table) contained Exotic tobacco in addition to white ribs.

Example 4

Another burley belt cast reconstituted tobacco sheet for split inner wrapping was made in a similar manner as described in example 2, except that the water-tobacco-wood pulp slurry was cooked with 1.75% (by dry weight) tobacco equivalent of caustic (KOH) at 70 ℃ to 90 ℃ for 30-45 minutes. Cooking tobacco with caustic causes the release of a natural binder, i.e., gum. The gum increases the tensile strength of the sheet and reduces the amount of binder used in the formulation.

The following 7 samples were made:

1. a commercial LTS KS band blend control without insert;

2. LTS KS with 2 inserts of 2 x 4mm burley paper;

3. LTS KS with 2 ribbed belt casting inserts of 2 × 4 mm;

4. LTS KS with 2 cooked ribbed belt casting inserts of 2 x 4 mm;

5. LTS KS with 2 x 4mm Exotic I blend tape casting inserts;

6. LTS KS with 2 x 4mm Exotic II blend tape casting inserts; and

7. LTS KS with 2X 4mm ExoticIII blend tape casting inserts.

LTS means "light smoke (lights)" and KS means "king size". The cigarettes were alcoholized in cardboard box packs at 70 ° F and 65% relative humidity for three weeks and subjected to sensory and routine testing.

The following table shows the ratings of 34-37 panelists for a commercial LTS KS strip blend control without insert (1) versus the LTS with burley paper reconstituted tobacco insert (2), LTS with burley belt cast reconstituted tobacco insert (3), LTS with cooked burley belt cast reconstituted tobacco insert (4), LTS with Exotic I blend reconstituted tobacco insert (5), LTS with Exotic II blend reconstituted tobacco insert (6), and LTS with Exotic iii blend reconstituted tobacco insert (7), where these LTS have been mentioned above and are described in the formula table above.

As can be seen from the above table, we found that the cigarette with the insert had a "stronger and better tobacco flavor" than the control without the insert, although the control had the highest tar/puff ratio, as shown in the following table:

smoking article comprising a split inner wrapping strip of burley-type slip cast reconstituted tobacco

The discrete partial inner wrapper strip 14 may be a strip of cast, paper, or extruded reconstituted tobacco manufactured according to a particular formulation and method of manufacture as previously described. The overwrap cigarette paper 12 may be normal porosity paper that typically exhibits a porosity of 15-80CORESTA units. As shown, two strips of reconstituted tobacco sheet 14a, 14b are provided on opposite sides of the tobacco column 13, providing a partial inner wrapper. The partial inner wrapper comprising the burley regenerated tobacco strips 14a, 14b may extend substantially the length of the tobacco column 13 and be coaxial with the tobacco column 13. In one embodiment, the strips 14a, 14b are positioned equidistant from one another to provide for even burning of the resulting cigarette.

The foregoing detailed description has been given primarily for clearness of understanding and no unnecessary limitations should be understood therefrom, as many modifications will be apparent to those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention and scope of the appended claims.

Claims (11)

1. A cigarette combining burn rate modification with a unique flavor from a limited supply of rare exotic tobacco in an amount substantially less than that required for inclusion in a tobacco column as said rare exotic tobacco, comprising:

a tobacco column surrounded by an outer wrapper; and

a tobacco inner wrapper extending substantially along the length of and coaxial with the tobacco column, the tobacco inner wrapper having a width of less than about 15mm and comprising a tobacco blend consisting of burley and a second limited supply of rare exotic tobacco, the second tobacco selected from the group consisting of ezm tobacco, samson tobacco, hilly hill tobacco, lataya tobacco, parque tobacco, board tobacco, yellow tobacco, open fire flue-cured tobacco and dark or sun-cured tobacco and combinations thereof and comprising up to about 30 weight percent of the tobacco inner wrapper, and the tobacco inner wrapper being disposed away from an outer wrapper seam of the outer wrapper.

2. The cigarette of claim 1, wherein the outer wrapper has a porosity greater than about 15CORESTA units and the tobacco inner wrapper has a porosity less than 10CORESTA units.

3. A cigarette as in claim 2 wherein the tobacco inner wrapper has a porosity of less than 7CORESTA units.

4. A cigarette according to claim 1, wherein the tobacco inner wrapper has a first tobacco inner wrapper strip and a second tobacco inner wrapper strip.

5. A cigarette according to claim 4, wherein the first tobacco inner wrapper strip and the second tobacco inner wrapper strip are each about 5mm wide.

6. A cigarette according to claim 4, wherein the first tobacco inner wrapper strip and the second tobacco inner wrapper strip each have a width of about 4mm or less.

7. A cigarette according to claim 1, wherein the tobacco inner wrapper is based on a bandcast tobacco material.

8. The cigarette of claim 1, wherein the tobacco inner wrapper has a width of between about 2mm and 15mm and a porosity of less than 1CORESTA unit.

9. A cigarette as in claim 1 wherein the tobacco inner wrapper comprises a plurality of tobacco inner wrapper strips coaxial with the tobacco column.

10. A cigarette according to claim 1, wherein the tobacco inner wrapper is a reconstituted tobacco material.

11. The cigarette of claim 1, wherein the tobacco inner wrapper is a polymer-based material.