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Publication numberUS20050056294 A1
Publication typeApplication
Application numberUS 10/909,040
Publication dateMar 17, 2005
Filing dateJul 30, 2004
Priority dateNov 19, 2002
Also published asCA2574826A1, CA2574826C, CN101065027A, CN101065027B, DE602005015228D1, EP1781124A2, EP1781124B1, WO2006014995A2, WO2006014995A3
Publication number10909040, 909040, US 2005/0056294 A1, US 2005/056294 A1, US 20050056294 A1, US 20050056294A1, US 2005056294 A1, US 2005056294A1, US-A1-20050056294, US-A1-2005056294, US2005/0056294A1, US2005/056294A1, US20050056294 A1, US20050056294A1, US2005056294 A1, US2005056294A1
InventorsJoseph Wanna, Douglas Hicks, Luis Monsalud, John-Paul Mua
Original AssigneeWanna Joseph T., Hicks Douglas R., Luis Monsalud, John-Paul Mua
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Modified reconstituted tobacco sheet
US 20050056294 A1
Abstract
A reconstituted tobacco sheet for use in a cigarette includes up to about 80% by weight of wood pulp, up to about 30% by weight of a binder, and up to about 80% by weight of tobacco. A humectant and a flavor may be included. The reconstituted tobacco sheet is used in elongated strips along the outer surface of a tobacco rod between the tobacco rod and an inner surface of an outer wrap of cigarette paper
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Claims(50)
1. A process for making a reconstituted tobacco sheet having a binder, comprising the steps of:
preparing a slurry containing a mixture of up to about 80% by weight tobacco, and up to about 30% by weight of said binder; and
coating a preformed reconstituted tobacco sheet, wherein said sheet contains up to about 80% wood pulp, with said slurry.
2. The process of claim 1, wherein said reconstituted sheet contains up to about 60% by weight of said wood pulp.
3. The process of claim 1, wherein said slurry contains up to about 20% by weight of said binder.
4. The process of claim 1, including the addition of up to about 30% by weight of a flavor in said solid mixture.
5. The process of claim 4, wherein said solid mixture contains from about 3% to about 5% by weight of said flavor.
6. The process of claim 1, said tobacco being firstly added to an aqueous solvent to from said slurry, and said binder being added to said slurry secondly, each of said tobacco and said binder being dispersed before adding to said preformed reconstituted tobacco sheet.
7. The process of claim 1, said binder being selected from the group consisting of alginate, guar, xanthan, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid based compounds.
8. The process of claim 7, wherein said alginate is sodium alginate.
9. The process of claim 1, including the addition of a humectant.
10. The process of claim 9, said humectant being selected from the group consisting of glycerin and propylene glycol.
11. The process of claim 10, said glycerin being up to 30% by weight of said mixture.
12. The process of claim 1, further comprising:
cutting said sheet of reconstituted tobacco into longitudinal strips;
inserting a plurality of said longitudinal strips of said reconstituted tobacco into a cigarette adjacent a column of tobacco.
13. A process for making a reconstituted tobacco sheet comprising the steps of:
preparing a slurry including a binder, a humectant, tobacco, and a flavoring, said tobacco being up to about 80% by weight and dispersed in an aqueous solvent into said slurry, said binder being up to about 30% by weight and dispersed secondly into said slurry, said humectant being up to about 30% by weight and dispersed thirdly into said slurry, and then up to about 30% by weight of flavor being dispersed lastly into said slurry;
coating a preformed reconstituted tobacco sheet with said slurry;
cutting said sheet of reconstituted tobacco into longitudinal strips; and
inserting a plurality of said longitudinal strips of said reconstituted tobacco into a cigarette adjacent a column of tobacco.
14. The process of claim 13, said binder being selected from the group consisting of alginate, guar, xanthan, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid based compounds.
15. The process of claim 14, wherein said alginate is sodium alginate
16. The process of claim 13, said humectant being selected from the group consisting of glycerin and propylene glycol.
17. A cigarette comprising:
a tobacco column surrounded by an outer wrap paper; and,
a partial inner wrap material extending longitudinally of said tobacco column and disposed between said outer wrap, said partial inner wrap being one or more strips of a reconstituted tobacco sheet which is comprised of up to about 80% by weight of wood pulp, up to about 30% by weight of a binder, and up to about 80% by weight of tobacco, said partial inner wrap being coated with a coating comprising up to about 80% by weight tobacco and up to about 30% by weight of a binder.
18. The cigarette of claim 17, including up to about 30% by weight of flavor in said inner wrap.
19. The cigarette of claim 18, wherein said flavor is from about 3% to about 5% by weight of said inner wrap.
20. The cigarette of claim 17, including up to about 30% by weight of a humectant in said inner wrap.
21. The cigarette of claim 20, said humectant being selected from the group consisting of glycerin and propylene glycol.
22. The cigarette of claim 17, said binder being selected from the group consisting of alginate, guar, xanthan, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid based compounds.
23. The cigarette of claim 22, said alginate being sodium alginate.
24. The cigarette of claim 17, wherein said wood pulp is up to about 60% by weight of said reconstituted tobacco sheet.
25. The cigarette of claim 17, wherein said binder is up to about 20% by weight of said reconstituted tobacco sheet.
26. A reconstituted tobacco sheet, comprised of up to about 80% by weight of wood pulp, up to about 30% by weight of binder, and up to about 80% by weight of tobacco.
27. The sheet of claim 26, wherein said wood pulp is up to about 60% by weight.
28. The sheet of claim 26, wherein said binder is up to about 20% by weight.
29. The sheet of claim 26, including up to about 30% by weight of flavor.
30. The sheet of claim 29, wherein said flavor is from about 3% to about 5% by weight.
31. The sheet of claim 26, including up to about 30% by weight of a humectant.
32. The sheet of claim 26, said humectant being selected from the group consisting of glycerin and propylene glycol.
33. The sheet of claim 26, said binder being selected from the group consisting of alginate, guar, xanthan, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid based compounds.
34. The sheet of claim 33, said alginate being sodium alginate.
35. The sheet of claim 26, wherein said reconstituted tobacco sheet is formed in a plurality of longitudinal strips, said strips inserted into a cigarette adjacent a column of tobacco.
36. The sheet of claim 35, wherein said plurality of longitudinal strips are a first and a second strip positioned equidistant from each other.
37. A process for making a modified reconstituted tobacco sheet, comprising the steps of:
preparing a slurry containing tobacco particles and an aqueous solvent;
extracting said slurry at about 160 F. for about 30 minutes;
separating said slurry into an extract with water soluble compounds and solid portion;
mixing said solid portion with wood pulp, wherein said wood is up to about 80% by weight;
forming said solid portion into a reconstituted tobacco sheet over a Fourdriner paper machine wire;
centrifuging and concentrating said extract;
adding a first binder to said extract, wherein said first binder is up to about 30% by weight;
adding a humectant to said extract, wherein said humectant is up to about 30% by weight;
applying said extract to said reconstituted tobacco sheet and drying;
slitting said reconstituted tobacco sheet into elongated strips; and
inserting a plurality of said elongated strips into a cigarette adjacent a column of tobacco.
38. The process of claim 37, said tobacco particles and said aqueous solvent being in a ratio of from about 1:11 to about 1:20.
39. The process of claim 37, wherein said solid portion and said wood pulp are further mixed with a second binder, said second binder being up to about 30% by weight.
40. The process of claim 39, said second binder being selected from the group consisting of alginate, guar, xanthan, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid compounds.
41. The process of claim 40, wherein said alginate is sodium alginate.
42. The process of claim 37, wherein said extract is treated with adsorbents.
43. The process of claim 37, said first binder being selected from the group consisting of alginate, guar, xanthan, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid compounds.
44. The process of claim 43, wherein said alginate is sodium alginate.
45. The process of claim 37, said humectant being selected from the group consisting of glycerin and propylene glycol.
46. The process of claim 37, including the addition of up to about 30% by weight of a flavor to said extract.
47. The process of claim 46, wherein said extract contains from about 3% to about 5% by weight of said flavor.
48. The process of claim 37, including the addition of an inert filler to said solid portion before forming said reconstituted tobacco sheet over said Fourdriner paper machine wire.
49. The process of claim 48, wherein said inert filler is selected from the group consisting of chalk, chitosan, liposan, or combinations thereof.
50. The process of claim 37, including the step of applying a third binder solution to said reconstituted tobacco sheet subsequent, wherein said binder is selected from the group consisting of alginate, guar, xanthan, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid based compounds.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This continuation-in-part application claims priority to and benefit from currently pending U.S. application Ser. No. 10/811,270, filed Mar. 26, 2004, which is a continuation-in-part of and claims priority to and benefit from currently pending U.S. application Ser. No. 10/299,231, filed Nov. 19, 2002, which are incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A “SEQUENTIAL LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

The present invention relates to a process for making a reconstituted tobacco sheet and more particularly to a process for making a reconstituted tobacco sheet including a flavoring compound contained in a gel matrix within the reconstituted tobacco sheet and even more particularly to a paper process for making a reconstituted tobacco sheet including an alginate based compound.

In the manufacturing of smoking articles and particularly cigarettes, it is common to use in the tobacco blend a percentage of strips of reconstituted tobacco. The reconstituted tobacco is generally prepared from tobacco fines, veins, stems and other waste tobacco products which are further processed and formed into sheets, cut into strips and blended in with fresh cut tobacco. The amount of reconstituted tobacco used in a tobacco blend for a smoking article varies, but is generally less than 20%. Usually, reconstituted tobacco sheets made via the paper process are absent of additional binders, such as alginate, guar, xanthan, acacia, pectin, other gums, and modified cellulose compounds.

Additionally, there has been great concern for the reduction of the ignition propensity of smoking articles as there have been a substantial number of fires which have been attributed to burning cigarettes coming into contact with combustible or flammable materials. Therefore, there is a considerable effort being expended in the industry to provide smoking articles which provide a low ignition propensity smoking article. Many of these proposals include a modification of the wrapper for the smoking article. Particularly, coatings or additives have been made to wrappers for the smoking articles to reduce the porosity or to change the chemical properties of the wrapper.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a novel formulation for a reconstituted tobacco sheet and the process for making same.

It is also an object of the present invention to provide a smoking article, including a novel reconstituted tobacco sheet in one layer of a wrapper for the smoking article.

It is a further object of the present invention to provide a novel formulation for a reconstituted tobacco sheet having an alginate based coating and the process or making same.

It is yet a further object of the present invention to provide a smoking article, including a novel reconstituted tobacco sheet having an alginate based coating in one layer of a wrapper for the smoking article.

The present invention provides a reconstituted tobacco sheet which includes up to about 80% by weight of tobacco; up to about 80% by weight of wood pulp, preferably up to about 60% by weight of wood pulp; up to about 30% by weight of a binder (e.g., alginate, guar, xanthan, acacia, pectin, other gums, and modified cellulose compounds), preferably up to about 20% by weight of a binder; and up to about 30% by weight of flavoring compounds, preferably about 3% to about 5% by weight of flavoring compounds.

Processes for making a reconstituted tobacco sheet are known in the art. The present invention provides a process for making a reconstituted tobacco sheet having a binder applied to the sheet to decrease sheet porosity, thereby lowering ignition propensity and cigarette burn rate. The binder may be alginate, guar, xanthum, acacia, pectin, other gums, and modified cellulose compounds. The resulting tobacco sheet with the applied binder is cut into lengths of preselected widths for use in a smoking article. In one embodiment, the strips are positioned longitudinally of the tobacco rod between the tobacco rod and an outer cigarette or smoking article wrapper.

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 the preparation of the reconstituted tobacco sheet of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects and advantages of the present invention will be better understood when the detailed description of the preferred embodiments is taken in conjunction with the accompanying drawings, in which:

FIG. 1 is perspective view of a partial cigarette of the present invention using the reconstituted tobacco sheet of the instant invention;

FIG. 2 is a perspective view of an unrolled cigarette wrapper including the reconstituted tobacco sheet of the instant invention;

FIG. 3 is an end view of the cigarette of FIG. 1;

FIG. 4 is a perspective view of the cigarette paper of an alternative embodiment of the instant invention including the reconstituted tobacco sheet;

FIG. 5 is a perspective view of the cigarette paper of an alternative embodiment of the instant invention including the reconstituted tobacco sheet;

FIG. 6 is an end view of FIG. 5; and,

FIG. 7 is a partial cut away view of a cigarette with the cigarette paper of an alternative embodiment of the instant invention including the reconstituted tobacco sheet.

FIG. 8 is a flow chart showing the modified paper reconstituted process for making split inner wrap.

DETAILED DESCRIPTION OF THE PREFERRED EMBDIMENTS

A cigarette with burn rate modification is shown in FIG. 1 and may be described as a partial double wrap cigarette 10. As seen therein, the partial double wrap cigarette 10 of the present invention incorporates a standard column of tobacco 13 which extends from an exposed end to the filter 15. Circumscribing the tobacco column 13 is the outer wrap of the cigarette paper 12. Interior of the outer wrap cigarette paper 12 is a separate partial inner wrap layer or strip 14 a and 14 b. The separate partial inner wrap layer 14 a and 14 b acts as a burn rate modifier for the tobacco column 13 by altering the burn characteristics of the cigarette 10. As can be seen from the embodiment shown in FIG. 1, the inner wrap layer strips may be co-axial to the tobacco column 13 and may extend substantially the length of the tobacco column from the exposed end to the filter 15. By insertion of the separate partial inner wrap layer 14 a and 14 b which in this embodiment extends co-axial to the tobacco column 13, modification may be made to the burn rate of the cigarette in such a manner that the burn rate may be adjusted depending upon the packing density of the tobacco, porosity of the outer wrap paper 12 and additives to the outer wrap, width of the separate partial inner wrap layer 14 a and 14 b, porosity of the inner wrap layers 14 a and 14 b, and additives to the inner wrap strips. Alternatively, the inner wrap layer may be shortened to not extend the full length of the tobacco column 13 or may extend in varying directions. Thus, many alterations to the burn rate of the partial double wrap cigarette 10 of the present invention may be established based upon the combination of factors noted herein, among others.

As depicted in FIG. 1, the partial double wrap cigarette 10 of the present invention which has a modified burn rate characteristic incorporates an outer wrap paper 12 with a first and a second separate partial inner wrap strip 14 a and 14 b. The outer wrap cigarette paper 12 may be a normal porosity paper which typically exhibits a porosity of 15-80 CORESTA units. In combination with the outer wrap cigarette paper 12 is positioned at least one partial inner wrap layer which can modify the burn rate characteristics of the cigarette 10. As shown, a first and a second partial inner wrap layer 14 a and 14 b are provided on opposite sides of the tobacco column 13. In order to provide substantially equivalent burn rate characteristics along the entirety of the tobacco column 13, the partial inner wrap strips 14 a and 14 b may substantially extend and be co-axial with the tobacco column 13 to the filter 15.

As depicted in the embodiment of FIG. 4, the partial inner wrap layers 14 a and 14 b extend from end to end of the tobacco column 13 and may be positioned such that they are either equal distant from each other or may be placed in alternative positions based upon the desired burn rate characteristics.

Turning to FIG. 3, it is apparent that the partial double wrap cigarette 10 of the present invention has alternating high diffusion areas 21 and low diffusion areas 22 based upon the placement of the inner wrap layers or strips 14 a and 14 b. As can be seen, the high diffusion areas 21 of which there is at least one, allow for increased permeation of CO and oxygen gases through the barrier formed by the outer wrap 12 while maintaining normal deliveries. In combination, low diffusion areas 22 which are defined by the circumferential extent of each of the partial inner wrap layers 14 a and 14 b may potentially block a significant portion or all of the inflow and outflow of gases therethrough related directly to the porosity of the inner wrap layer 14 a and 14 b in combination with the outer wrap layer 12. The co-linear zones of high diffusion area 21 and low diffusion area 22 may exhibit a porosity of greater than 14 CORESTA for the co-linear high diffusion areas and less than 8 CORESTA for the co-linear low diffusion areas.

As shown in the drawings, the construction of the cigarette with burn rate modification is a partial double wrap cigarette 10 depicted herein and utilizes a standard outer wrap cigarette paper 12 which, in a typical cigarette, is 27 mm wide. Placed along the interior of the outer wrap, as shown in FIG. 2 and in FIG. 4 in an alternative embodiment, is located the separate partial inner wrap layer 14 a and 14 b which may substantially extend along the length of the outer wrap 12. While the outer wrap of the cigarette paper may be standard porosity and construction, the partial inner wrap of this embodiment has a first and a second strip 14 a and 14 b each of which may be 4 mm in width and which may have a porosity of less than 8 CORESTA units. Therefore, combined, the two inner wrap layers or strips 14 a and 14 b may circumscribe about 8 mm of the circumference of the partial double wrap cigarette 10 of the present invention but may extend around a circumference of up to 15 mm of the tobacco column in relation to a standard cigarette dimension. Any combination of the partial inner wrap and outer wrap may work depending on the variables noted, such as porosity of each paper, but it is felt that good burn rate characteristics as well as limited effects to smoke characteristics and flavor may be achieved by incorporating an inner wrap which 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 wrap. This is a function of the overall cigarette and may vary depending on the circumference of the outer wrap. However, variations are available to achieve the same favorable results utilizing the inventive aspects of the present design and such descriptions are not felt to be limiting and are exemplary only.

Alternatively, many different constructions may be utilized to provide the cigarette with burn rate modification as set forth herein. As may be understood, a single inner wrap layer or a plurality of inner wrap layers may be provided based upon the desired characteristics and burn rate modification. Thus, as previously mentioned, combinations of low porosity inner wrap segments and higher porosity outer wrap segments may be utilized to provide various linear burn rates which may be desirable. Thus, a typical linear burn rate of 6.0 mm per minute may be reduced as desired based upon a combination of porosity of outer wrap and partial inner wrap strips among other factors and may readily be reduced to below 4 mm/minute if needed. This includes formulation of single inner wrap strips of lower porosity or replacement of the inner wrap strips with various construction material including reconstituted tobacco, low porosity paper, reconstituted tobacco, a polymer based material, other paper or material. The inner wrap strips are coated with binders, such as alginates (e.g., sodium alginate), guar, xanthum, acacia, pectin, other gums, modified cellulose compounds or hydrocolloid-based compounds, which act as burn modifiers or inhibitors and which create at least one low diffusion area along the tobacco column. The binders decrease the porosity of the coated reconstituted tobacco sheet, which are used as inner strips, and provide adequate characteristics such that the entire combination of outer wrap porosity, tobacco packing density, inner strip burning characteristics, inner strip porosity, and other factors cause the cigarette to exhibit a desired burn rate.

As shown in FIGS. 4-7, various embodiments may be utilized in order to create the low porosity zone. As depicted in FIG. 4, the opened standard outer wrap 12 is lined with a plurality of inner wrap or inner layer strips 16 a, 16 b, 16 c and 16 d. These strips may be placed equidistantly apart along the interior of the outer wrap 12 and positioned away from the edges or seam where the outer wrap is adhered to itself during rolling within the garniture of the cigarette maker. As depicted, the strips 16 a-16 d may all be fed into the garniture and incorporated on the interior of the outer wrap adjacent the tobacco column. Placement of the partial inner wrap strips coated with an alginate based compound modifies the burn rate to a desired level such that the rate may be decreased sufficiently to cause either a significantly reduced static burn rate or self-extinguishment at a desired interval.

As shown in FIG. 5, an inner layer with non-linear sides 17 as compared to the edges of the outer wrap 12 may be utilized as the partial inner wrap in order to create the low porosity zone. As shown therein, the inner wrap layer 17 may have be a wave form so that the placement of the low porosity zone changes in position along the tobacco column axis. Such non-linear placement of the low porosity zone may allow for different positioning of the cigarette during static burn and insure that the desired static burn rate takes effect regardless of the position of the cigarette.

Depicted in FIG. 6 is another embodiment of the cigarette with burn rate modification of the present invention. As seen therein, a high diffusion area 21 and low diffusion area 22 is defined by addition of a partial double wrap inner wrap layer 18 which circumscribes a portion of the tobacco column 13 on the interior of outer wrap 12. The partial inner wrap layer 18, as depicted in the FIG. 6, extends approximately halfway around the perimeter of the tobacco column 13. However, many different configurations may be utilized in order to achieve the appropriate linear burn rate through the burn rate modification set forth. The partial double wrap inner wrap layer 18 may be comprised of standard cigarette paper which has a low porosity of less than 7 CORESTA units or cigarette paper coated with burn rate modifiers, or may be alternative construction such as a reconstituted tobacco sheet with or without additives and which typically has a low CORESTA unit value, typically less than 5 and more preferably less than 3. A secondary benefit of utilizing reconstituted or reconstituted tobacco sheets as the partial double wrap inner wrap layer 18 is that the coloring of the inner wrap may be such that it is similar to the tobacco column 13 and does not provide a contrasting whitened area which extends along the low diffusion area 22. Additionally, a polymer film or other material may be used as the partial double wrap inner wrap layer 18. It may be preferable for the partial double wrap inner layer displayed in FIG. 6 to be 2-14 mm in width or alternatively, less than 75% of the circumference of the outer wrap in order to obtain the appropriate burn rate modification desired wherein the linear burn rate is sustained at a low enough level, preferably below 4.0 mm per minute.

As depicted in FIG. 7, an alternative embodiment is disclosed wherein a plurality of inner wrap strips 19 are utilized substantially surrounding the tobacco column 13 on the interior of the outer wrap 12. The plurality of inner wrap strips 19 may be fed into the garniture adjacent the outer wrap 12 and encircling the tobacco column 13 as it is formed within the cigarette maker. The plurality of strips 19 may be comprised of a low porosity cigarette paper individually fed into the cigarette maker or by a single or multiple strips fed into the cigarette maker adjacent to the garniture and cut to the appropriate strip widths. As depicted in FIG. 7, a plurality of inner wrap strips 19 are utilized and extend co-axially substantially along the length of the tobacco column 13. Preferably, the plurality of strips 19 extends along the entire tobacco column length such as to modify the burn rate along the entire tobacco column regardless of cigarette positioning. It is felt that by providing a plurality of strips 19 as depicted in FIG. 7, a more even modification of the burn rate of the cigarette may be produced.

As may be appreciated, extending the inner wrap layer substantially along the length of the tobacco column 13 such that they are co-axial provides a significant benefit over alternating rings which are perpendicular to the axis of the tobacco column 13. Such perpendicular rings which alternate along the length of the tobacco column may provide a non-linear burn rate of the tobacco column 13. Thus, in such a design where there are circumscribing rings around the tobacco column, the linear burn rate becomes variable between a low linear burn rate to a high linear burn rate depending upon the porosity of the paper at the point of the rings as opposed to the porosity of the non-adjusted paper between the rings. Such non-linear burn rate may in fact be undesirable in that continued free burning of the tobacco column between the rings for significant periods of time does not produce an appropriate burn rate modification which can be depended upon through the entire tobacco column length. Further, at points where the low porosity rings are present, a smoker may puff on the cigarette as the burning of the tobacco column passes over a low porosity ring. At such a point, it is thought that the deliveries of the cigarette may be altered significantly to increase the CO and other compounds provided as the cigarette burns over one of these rings. Thus, the partial double wrap inner layer of the present invention overcomes these problems by providing known standard deliveries over the entire length of the tobacco column while also modifying the burn rate along the entire co-axial length.

In the design of the cigarette with the burn rate modification 10 of the present invention, it may be desirable to incorporate the inner wrap layers, whether a plurality of strips or a single layer, away from the seam of the outer wrap 12. As is known in cigarette manufacturing, the seam 23, depicted in FIG. 1, is formed by the maker by over-wrapping the side edges 24 of the outer wrap 12. In typical cigarette manufacturing, an adhesive is applied along one of the edges 24 prior to folding of the outer wrap and formation of the tobacco column 13. During manufacturing of the cigarette with burn rate modification 10 of the present invention, it is desirable to maintain the partial inner wrap layer away from the seam portion to assure that the outer wrap 12 is properly formed and the partial inner wrap layer does not intercede in the formation of the tobacco column or adhesive of the outer wrap layer. Thus, as depicted in the embodiments, the partial inner wrap layers are shown to be placed away from the side edges 24 so that the inner wrap portions will not interfere with the seam of the outer wrap 12 nor interfere with the formation of the tobacco column within the garniture in a typical cigarette manufacturing machine. Thus, the cigarette with burn rate modification of the present invention may be implemented on standard cigarette making machines with only minor modifications made to the paper feeding devices and no modifications therefore will necessarily be required within the garniture. It is also apparent that in any of the embodiments shown herein the strips may be alternatively placed on the exterior of the cigarette and retained on the wrapper by adhesives or other means so that there are still formed co-linear zones of high and low porosity.

The cigarette with burn rate modification of the present invention may be designed with variations in outer wrap and inner wrap paper characteristics. As previously explained, standard outer wrap designs are such that the typical outer wrap has a linear laid out width of 27 mm and generally a porosity of between 15 and 80 CORESTA units. As is generally understood, significantly decreasing the outer wrap porosity changes the deliveries and linear burn rate of the cigarette. Modification of the standard burn rate for a normal or typical cigarette may be obtained through addition of a partial inner wrap to the cigarette. The partial inner wrap may be a single inner wrap portion or may be a plurality of inner wrap strips as shown in the various figures. The partial inner wrap may have paper characteristics with a significantly reduced porosity such that the inner wrap paper exhibits a porosity of less than 8 CORESTA units. If a single inner wrap strip is utilized, the inner wrap layer may have a width of between 2-15 mm. The porosity of the inner wrap layer may be adjusted from any where to 0 to 8 CORESTA units.

EXAMPLES

A more comprehensive understanding of the invention can be obtained by considering the following examples. However, it should be understood that the examples are not intended to be unduly limitative of the invention.

Example 1

Several product examples were made using the construction of a partial strip wrap or partial inner wrap cigarette using the inventive techniques and construction described herein. In the examples, a control cigarette was used having no partial inner wrap strips which exhibited a linear burn rate of between 4.3-4.7 mm/min. Different materials were utilized, as detailed in the chart below, for the partial inner wrap strips ranging from standard treated paper to band cast tobacco material.

Examples of cigarettes with two band cast inner wrap strips having a porosity of band cast material less than 5 CORESTA units:

Outer Outer Self
Wrapper Wrap Inner Inner Strip Linear Burn Extinguishment
Porosity Citrate Strips Width Rate (LBR) On 10 layers
Cig. CORESTA % Number mm mm/min %
1 50 0.5 0 0 4.3 0
2 50 0.5 2 4 3.1 100
3 50 0.5 2 5 2.6 100
4 50 0.5 2 6 2.7 100
5 40 0.7 0 0 4.7 0
6 40 0.7 2 3 3.8 48
7 30 0.6 0 0 4.3 0
8 30 0.6 2 4 3.1 100

Examples of cigarettes with two cigarette paper strips treated or covered with sodium alginate having a porosity of inner strip paper less than 5 CORESTA units:

Outer Outer Inner Self
Wrapper Wrap Strip Linear Burn Extinguishment
Porosity Citrate Inner Strips Width Rate (LBR) On 10 layers
Cig. CORESTA % Number mm mm/min %
9 70 0.6 0 0 4.4 0
10 70 0.6 2 2 3.8 25

Examples of cigarettes detailing smoke deliveries of two samples with band cast strips:

Outer Outer Inner Self Nico-
Wrapper Wrap Inner Strip Linear Burn Extinguishment tar tine CO Puff
Porosity Citrate Strip Width Rate (LBR) On 10 layers mg/ mg/ mg/ Num-
Cig CORESTA % Number mm mm/min % cig cig cig ber
11 70 0.6 2 4 3.9 90 15.5 1.4 12.2 10.3
12 50 0.5 2 4 3.8 90 14.5 0.9 14.6 7.3

In the examples presented, it is apparent that the addition of the partial inner wrap to the cigarette had a definite impact on linear burn rate and self extinguishment as compared to the control cigarette. The linear burn rate for the cigarettes using the present invention was directly affected and evidenced a reduction in linear burn rate by up to 40 percent. Where inner wrap strips were utilized having a width of at least 4 mm, all test samples self extinguished. Narrower width strips had differing results which could be modified by using alternative additives or increasing the number of strips. References to the self-extinguishment of the cigarette on 10 layers are related to the NIST test for cigarette ignition propensity.

Smoking Article Including Strips of Reconstituted Tobacco

The separate partial inner wrap strips 14 may be strips of reconstituted tobacco made in accordance with the specific formula and process for making same as discussed hereinafter. The outer wrap cigarette paper 12 may be a normal porosity paper which typically exhibits a porosity of 15-80 CORESTA units. As shown, two strips 14 of a reconstituted tobacco sheet are provided on opposite sides of the tobacco column 13 to provide a partial inner wrap layer. The partial inner wrap layer including the reconstituted tobacco strips 14 may extend substantially the length of and be co-axial with the tobacco column 13. In one embodiment, the strips are placed equidistant from each other such that the resulting cigarette burns evenly.

Preparation of a Reconstituted Tobacco Sheet Having Binder

FIG. 8 is a flowchart illustrating the modified reconstituted tobacco process for making split inner wraps. In the preparation of a reconstituted tobacco sheet for use in a cigarette, tobacco particles, such as tobacco fines, stems, scraps, cut lamina, shredded stems, or combinations thereof are slurried in an aqueous solvent, such as water, wherein the ratio is one part tobacco to 11-20 parts aqueous solvent. The solution is extracted at about 160 F. for about 30 minutes. The solution is then separated into an extract with water soluble compounds and solid/fibrous portion via separation techniques known in the art, such as centrifugation or filtration. The solid/fibrous portion is refined and mixed with over 10% wood pulp, made from wood fibers that have been refined to a pulp, and an optional second binder, such as alginate (e.g., sodium alginate), guar, xanthum, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid based compounds. This mixture of solid/fibrous tobacco, wood pulp, and optional second binder is then made into a reconstituted tobacco sheet via a paper process known in the art.

The extract, meanwhile, can optionally be treated with particular adsorbents to selectively remove undesired constituents. The extract is then centrifuged and the adsorbent now containing the constituents is discarded. The extract is then concentrated. A first binder, such as alginate (e.g. sodium alginate), guar, xanthum, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid-based compounds is added to the extract. Also, a humectant, such as glycerin, can be added for sheet pliability and is generally added before the binder and before any additional flavorant. A desired flavoring can also be added to the extract.

The new extract mixture is then reapplied to the preformed reconstituted tobacco sheet. Optionally, a third binder mix solution, such as alginate (e.g., sodium alginate), guar, xanthum, acacia, pectin, other gums, modified cellulose compounds, and hydrocolloid-based compounds, can be size pressed and/or sprayed onto the reconstituted tobacco sheet. The reconstituted tobacco sheet can then be dried and slit into elongated strips of a desired width and wound onto a bobbin. The elongated strips can be used as longitudinally extending strips along the outer periphery of a tobacco rod and the inner surface of an outer paper wrap.

In a preferred mix, the tobacco is up to about 80% by weight; the wood pulp is up to about 80% by weight, preferably up to about 60% by weight; the binder is up to about 30% by weight, preferably up to about 20% by weight; and, if a flavoring is added, the flavoring will be up to about 30% by weight, preferably from about 3% to about 5% by weight.

The following examples demonstrate the procedure that was followed in preparing the reconstituted tobacco sheet having a binder for use in a smoking article.

Example 2

In the process of making a reconstituted tobacco sheet, 500 pounds of a combination of tobacco and wood pulp (1:3 to 3:1 ratio) was extracted with 750 gallons of water in a mixing vessel, at 140 C. to 190 C. for 30 to 45 minutes. Following extraction, the mixture was separated into solids (fiber) and liquid (extract) streams via centrifugation, filtration, or pressing.

The liquid extract was concentrated by vacuum evaporation and mixed thoroughly with 60 pounds of glycerin. In a separate vessel, an alginate solution was prepared by thoroughly dispersing 40 pounds of sodium alginate in 135 gallons of water. The concentrated extract with glycerin was then thoroughly mixed with the alginate solution. Optionally, the liquid extract was gently agitated for 20 to 45 minutes with 75 pounds of a powdered solid adsorbent, such as bentonite (diatomaceous earth), carbon, cyclodextrin, cellulose acetate, or combinations thereof, to selectively remove nitrogen and other undesired components. After agitation, the adsorbent was separated and discarded from the extract via centrifugation. The extract was then concentrated and treated with glycerin and alginate as described above.

Meanwhile, the solid stream was put through a refiner to fibrillate the fibers into a tobacco-wood pulp. The pulp was then used to make base sheets over a Fourdriner paper machine wire and dried. Any of the two concentrated extracts as prepared above were then added back to the base sheets either via size pressing or spraying. The finished sheet was finally dried and slit into strips and wound onto bobbins to be used as split inner wraps.

Example 3

Sheets were prepared and slit as described in Example 2, except that the alginate solution was added directly to the base sheet, instead of being mixed with the concentrated extract. Also, 25 pounds of precipitated chalk or chitosan (inorganic or organic inert fillers) were added to the refined pulp mixture before making base sheet over the Fourdriner machine wire. Other inert fillers include liposan and combinations of chalk, chitosan, and liposan.

It is to be understood that the invention is not to be limited to the specific examples shown, because the parameters set forth in the examples may be varied by appropriate changes of the amounts of the constituents within the reconstituted tobacco sheet mix used in the examples.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7946296May 23, 2007May 24, 2011Philip Morris Usa Inc.Dissolvable tobacco film strips and method of making the same
Classifications
U.S. Classification131/372, 131/370
International ClassificationA24B15/14, A24C5/20, A24C5/18, A24D1/02
Cooperative ClassificationA24D1/025, A24B3/14, A24B15/14
European ClassificationA24B3/14, A24B15/14, A24D1/02B
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