U.S. patent application number 12/859494 was filed with the patent office on 2012-02-23 for segmented smoking article with monolithic substrate.
Invention is credited to Chandra K. Banerjee, Yi-Ping Chang, Billy Tyrone Conner, James Richard Stone.
Application Number | 20120042885 12/859494 |
Document ID | / |
Family ID | 45593068 |
Filed Date | 2012-02-23 |
United States Patent
Application |
20120042885 |
Kind Code |
A1 |
Stone; James Richard ; et
al. |
February 23, 2012 |
SEGMENTED SMOKING ARTICLE WITH MONOLITHIC SUBSTRATE
Abstract
A cigarette includes lighting and mouth ends. It may include a
smokable segment disposed at the lighting end. It also includes a
mouth-end segment; an aerosol-generation system disposed between
the lighting and mouth ends, which includes (i) a heat-generation
segment adjacent the smokable segment, including a heat source
configured to be activated by combustion of a smokable material and
an insulation layer, and (ii) an aerosol-generating segment
including a monolithic substrate with aerosol-forming material
disposed between, but physically separate from, each of the heat
generation segment and the mouth end; a piece of outer wrapping
material that provides an overwrap around at least a portion of the
aerosol-generating segment, the heat-generation segment, and at
least a portion of the smokable segment; those segments being
connected together by the overwrap to provide a cigarette rod; that
is connected to the cigarette rod using tipping material.
Inventors: |
Stone; James Richard;
(Advance, NC) ; Banerjee; Chandra K.; (Clemmons,
NC) ; Chang; Yi-Ping; (Greensboro, NC) ;
Conner; Billy Tyrone; (Clemmons, NC) |
Family ID: |
45593068 |
Appl. No.: |
12/859494 |
Filed: |
August 19, 2010 |
Current U.S.
Class: |
131/194 ;
131/352 |
Current CPC
Class: |
A24B 15/165 20130101;
A24F 47/006 20130101 |
Class at
Publication: |
131/194 ;
131/352 |
International
Class: |
A24F 13/00 20060101
A24F013/00; A24B 15/00 20060101 A24B015/00 |
Claims
1. A cigarette comprising: a lighting end and a mouth end; a mouth
end piece segment disposed at the mouth end; and an
aerosol-generation system disposed between the lighting end and the
mouth end piece segment, the aerosol-generation system including a
heat generation segment disposed at the lighting end having a
length including a heat source configured to be activated by
ignition of the lighting end and an insulation layer of
flame-retardant material disposed around the heat source; an
aerosol-generating segment incorporating aerosol-forming material,
said aerosol-generating segment having a length and being disposed
between, but physically separate from, each of the heat generation
segment and the mouth end, wherein the aerosol-generating segment
includes a monolithic substrate.
2. The cigarette of claim 1, wherein the monolithic substrate
comprises about one-tenth to about one-half of a total length of
the cigarette.
3. The cigarette of claim 1, wherein the monolithic substrate
comprises tobacco, glycerin, water, and a binder.
4. The cigarette of claim 3, wherein the monolithic substrate
further comprises a selected one of calcium carbonate or graphite
as a filler.
5. The cigarette of claim 1, wherein the monolithic substrate
comprises about 10 to about 90 weight-percent tobacco.
6. The cigarette of claim 1, wherein the monolithic substrate
comprises a mixture of flue-cured, Burley, and Turkish
tobaccos.
7. The cigarette of claim 1, wherein the monolithic substrate
comprises a center-hole disposed longitudinally through a length
thereof.
8. The cigarette of claim 1, wherein the monolithic substrate
comprises at least one slot on an exterior surface thereof.
9. The cigarette of claim 1, wherein the monolithic substrate
comprises diammonium phosphate.
10. The cigarette of claim 1, wherein the monolithic substrate
comprises a plurality of channels longitudinally disposed
therethrough.
11. The cigarette of claim 1, further comprising a hollow spacing
tube disposed between the monolithic substrate and the mouth
end.
12. The cigarette of claim 1, further comprising a tobacco rod
disposed between the monolithic substrate and the mouth end.
13. The cigarette of claim 1, wherein the monolithic substrate
comprises an outer diameter of about 5 mm to about 10 mm.
14. The cigarette of claim 1, wherein the monolithic substrate
comprises a generally cylindrical outer geometry.
15. The cigarette of claim 1, wherein the lighting end comprises a
tobacco portion distal of the heat source.
16. The cigarette of claim 1, wherein the monolithic substrate
comprises about 10 to about 90 weight-percent tobacco, about 5 to
about 50 weight-percent glycerin, about 1 to about 30
weight-percent water, and about 0 to about 10 weight-percent
binder.
17. The cigarette of claim 1, wherein the monolithic substrate
comprises about 23 to about 58 weight-percent tobacco, about 22 to
about 32 weight-percent glycerin, about 1 to about 16
weight-percent water, and about 1 to about 4 weight-percent
binder.
18. A monolithic substrate member configured for use in a smoking
article, the monolithic substrate comprising: a composition
including about 10 to about 90 weight-percent tobacco, about 5 to
about 50 weight-percent glycerin, about 1 to about 30
weight-percent water, and about 0 to about 10 weight-percent
binder; a body having generally cylindrical outer geometry of about
10 mm to about 50 mm in length; at least one center-hole formed as
a longitudinal channel through the body.
19. The monolithic substrate member of claim 18, further comprising
a plurality of grooves on an external body surface.
20. A cigarette comprising the monolithic substrate member of claim
19.
Description
TECHNICAL FIELD
[0001] The present invention relates to products made or derived
from tobacco, or that otherwise incorporate tobacco, and are
intended for human consumption. The present application relates
particularly to components and configurations of segmented-type
smoking articles.
BACKGROUND
[0002] Popular smoking articles, such as cigarettes, have a
substantially cylindrical rod-shaped structure and include a
charge, roll or column of smokable material, such as shredded
tobacco (e.g., in cut filler form), surrounded by a paper wrapper,
thereby forming a so-called "smokable rod", "tobacco rod" or
"cigarette rod." Normally, a cigarette has a cylindrical filter
element aligned in an end-to-end relationship with the tobacco rod.
Preferably, a filter element comprises plasticized cellulose
acetate tow circumscribed by a paper material known as "plug wrap."
Preferably, the filter element is attached to one end of the
tobacco rod using a circumscribing wrapping material known as
"tipping paper." It also has become desirable to perforate the
tipping material and plug wrap, in order to provide dilution of
drawn mainstream smoke with ambient air. Descriptions of cigarettes
and the various components thereof are set forth in Tobacco
Production, Chemistry and Technology, Davis et al. (Eds.) (1999)
and U.S. Pat. No. 7,503,330 to Borschke et al, which is
incorporated herein by reference. A cigarette is employed by a
smoker by lighting one end thereof and burning the tobacco rod. The
smoker then receives mainstream smoke into his/her mouth by drawing
on the opposite end (e.g., the filter end) of the cigarette.
[0003] Certain types of cigarettes that employ carbonaceous fuel
elements have been commercially marketed under the brand names
"Premier" and "Eclipse" by R. J. Reynolds Tobacco Company. See, for
example, those types of cigarettes described in Chemical and
Biological Studies on New Cigarette Prototypes that Heat Instead of
Burn Tobacco, R. J. Reynolds Tobacco Company Monograph (1988) and
Inhalation Toxicology, 12:5, p. 1-58 (2000). More recently, a
cigarette has been marketed in Japan by Japan Tobacco Inc. under
the brand name "Steam Hot One. It has also been suggested that the
carbonaceous fuel elements of segmented types of cigarettes may
incorporate ultrafine particles of metals and metal oxides. See,
for example, U.S. Pat. App. Pub. No. 2005/0274390 to Banerjee et
al., which is incorporated by reference herein in its entirety.
[0004] Yet other types of smoking articles, such as those types of
smoking articles that generate flavored vapors by subjecting
tobacco or processed tobaccos to heat produced from chemical or
electrical heat sources are described in U.S. Pat. Nos. 5,285,798
to Banerjee et al. and 7,290,549 to Banerjee et al., and U.S. Pat.
App. Pub. No. 2008/0092912 to Robinson et al., which are
incorporated by reference herein in their entirety. One type of
smoking article that has employed electrical energy to produce heat
has been commercially marketed by Philip Morris Inc. under the
brand name "Accord."
[0005] Smoking articles that employ sources of heat other than
tobacco cut filler to produce tobacco-flavored vapors or
tobacco-flavored visible aerosols have not received widespread
commercial success. However, it would be highly desirable to
provide smoking articles that demonstrate the ability to provide to
a smoker many of the benefits and advantages of conventional
cigarette smoking, without delivering considerable quantities of
incomplete combustion and pyrolysis products.
SUMMARY
[0006] Embodiments of the present invention relate to smoking
articles, and in particular, to rod-shaped smoking articles, such
as cigarettes. A smoking article includes a lighting end (i.e., an
upstream end) and a mouth end (i.e., a downstream end). The smoking
article also includes an aerosol-generation system that includes
(i) a heat generation segment, and (ii) an aerosol-generating
region or segment located downstream from the heat generation
segment. The smoking article may be configured in a variety of
ways, including various insulative configurations related to the
heat generation segment that may include one or more of glass or
non-glass fiber materials that may or may not be woven, foamed
monolithic material selected from metal, ceramic, and ceramic-metal
composite (e.g., cermet), or other materials, which materials may
also be incorporated in a buffer region between the heat generation
and aerosol-generation segments.
[0007] Further features and advantages of the present invention are
set forth in more detail in the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Embodiments may better be understood with reference to the
following drawings, which are illustrative only and are not
limiting.
[0009] FIG. 1 and FIG. 2 provide longitudinal cross-sectional views
of representative smoking articles;
[0010] FIG. 3 shows a representative fuel element;
[0011] FIGS. 4A-4G show representative fuel element and insulation
embodiments;
[0012] FIG. 5 shows another representative smoking article
embodiment;
[0013] FIGS. 6A-6D show representative monolithic substrate element
embodiments; and
[0014] FIGS. 7-9 each show a longitudinal cross-sectional view of a
representative smoking article including a monolithic
substrate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Aspects and embodiments of the present invention relating to
various smoking articles, the arrangement of various components
thereof, and the manner that those smoking articles incorporate
overwrap components, are illustrated with reference to FIGS. 1 and
2. Like components are given like numeric designations throughout
the figures. For the various figures, the thicknesses of the
various wrapping materials and overwraps of the various smoking
articles and smoking article components are exaggerated. Most
preferably, wrapping materials and overwrap components are tightly
wrapped around the smoking articles and smoking article components
to provide a tight fit, and provide an aesthetically pleasing
appearance. Exemplary smoking article construction may include
features such as fibrous filter elements, foamed ceramic monoliths
formed as insulators or fuel elements, and other features disclosed
in U.S. patent application Ser. No. 12/546,107 to Sebastian, et
al., filed Aug. 24, 2009, which is incorporated herein by reference
in its entirety.
[0016] Referring to FIG. 1, a representative smoking article 10 in
the form of a cigarette is shown. The smoking article 10 has a
rod-like shape, and includes a lighting end 14 and a mouth end
18.
[0017] At the lighting end 14 is positioned a longitudinally
extending, generally cylindrical smokable lighting end segment 22,
incorporating smokable material 26. A representative smokable
material 26 can be a plant-derived material (e.g., tobacco material
in cut filler form). An exemplary cylindrical smokable lighting end
segment 22 includes a charge or roll of the smokable material 26
(e.g., tobacco cut filler) wrapped or disposed within, and
circumscribed by, a paper wrapping material 30. As such, the
longitudinally extending outer surface of that cylindrical smokable
lighting end segment 22 is provided by the wrapping material 30.
Preferably, both ends of the segment 22 are open to expose the
smokable material 26. The smokable lighting end segment 22 can be
configured so that smokable material 26 and wrapping material 30
each extend along the entire length thereof.
[0018] Located downstream from the smokable lighting end segment 22
is a longitudinally extending, generally cylindrical heat
generation segment 35. The heat generation segment 35 includes a
heat source 40 circumscribed by insulation 42, which may be
coaxially encircled by wrapping material 45. The heat source 40
preferably is configured to be activated by combustion of the
smokable material 26. Ignition and combustion of the smoking
material preferably provide a user with a desirable experience
(with respect at least to flavor and time taken to light the
smoking article 10). The heat generated as the smokable material is
consumed most preferably is sufficient to ignite or otherwise
activate the heat source 40.
[0019] The heat source 40 may include a combustible fuel element
that has a generally cylindrical shape and can incorporate a
combustible carbonaceous material. Carbonaceous materials generally
have high carbon contents. Preferred carbonaceous materials are
composed predominately of carbon, typically have carbon contents of
greater than about 60 percent, generally greater than about 70
percent, often greater than about 80 percent, and frequently
greater than about 90 percent, on a dry weight basis. Fuel elements
can incorporate components other than combustible carbonaceous
materials (e.g., tobacco components, such as powdered tobaccos or
tobacco extracts; flavoring agents; salts, such as sodium chloride,
potassium chloride and sodium carbonate; heat stable graphite
fibers; iron oxide powder; glass filaments; powdered calcium
carbonate; alumina granules; ammonia sources, such as ammonia
salts; and/or binding agents, such as guar gum, ammonium alginate
and sodium alginate). A representative fuel element has a length of
about 12 mm and an overall outside diameter of about 4.2 mm. A
representative fuel element can be extruded or compounded using a
ground or powdered carbonaceous material, and has a density that is
greater than about 0.5 g/cm.sup.3, often greater than about 0.7
g/cm.sup.3, and frequently greater than about 1g/cm.sup.3, on a dry
weight basis. See, for example, the types of fuel element
components, formulations and designs set forth in U.S. Pat. No.
5,551,451 to Riggs et al. and U.S. Pat. App. Pub. No. 2009/0090373
to Borschke et al., which are incorporated herein by reference in
their entirety. Particular embodiments of fuel elements are
described below with reference to FIG. 3.
[0020] Another embodiment of a fuel element 40 may include a foamed
carbon monolith formed in a foam process. In another embodiment,
the fuel element 40 may be co-extruded with a layer of insulation
42, thereby reducing manufacturing time and expense. Still other
embodiments of fuel elements may include those of the types
described in U.S. Pat. No. 4,922,901 to Brooks et al. or U.S. Pat.
App. Pub. No. 2009/0044818 to Takeuchi et al., each of which is
incorporated herein by reference.
[0021] A representative layer of insulation 42 can comprise glass
filaments or fibers. The insulation 42 can act as a jacket that
assists in maintaining the heat source 40 firmly in place within
the smoking article 10. The insulation 42 can be provided as a
multi-layer component including an inner layer or mat 47 of
non-woven glass filaments, an intermediate layer of reconstituted
tobacco paper 48, and an outer layer of non-woven glass filaments
49. These may be concentrically oriented or each overwrapping
and/or circumscribing the heat source.
[0022] In one embodiment, the inner layer 47 of insulation may
include a variety of glass or non-glass filaments or fibers that
are woven, knit, or both woven and knit (such as, for example,
so-called 3-D woven/knit hybrid mats). When woven, an inner layer
47 may be formed as a woven mat or tube. A woven or knitted mat or
tube can provide superior control of air flow with regard to
evenness across the insulation layer, including as any
thermal-related changes may occur to the layer). Those of skill in
the art will appreciate that a woven, knit, or hybrid material may
provide more regular and consistent air spaces/gaps between the
filaments or fibers as compared to a non-woven material which is
more likely to have irregularly closed and open spaces that may
provide comparatively non-uniform and/or decreased air-flow.
Various other insulation embodiments may be molded, extruded,
foamed, or otherwise formed. Particular embodiments of insulation
structures are described below with reference to FIGS. 4A-4G.
[0023] Preferably, both ends of the heat generation segment 35 are
open to expose the heat source 40 and insulation 42 to the adjacent
segments. The heat source 40 and the surrounding insulation 42 can
be configured so that the length of both materials is co-extensive
(i.e., the ends of the insulation 42 are flush with the respective
ends of the heat source 40, and particularly at the downstream end
of the heat generation segment). Optionally, though not necessarily
preferably, the insulation 42 may extend slightly beyond (e.g.,
from about 0.5 mm to about 2 mm beyond) either or both ends of the
heat source 40. Moreover, smoke produced when the smokable lighting
end segment 22 is burned during use of the smoking article 10 can
readily pass through the heat generation segment 35 during draw by
the smoker on the mouth end 18.
[0024] The heat generation segment 35 preferably is positioned
adjacent to the downstream end of the smokable lighting end segment
22 such that those segments are axially aligned in an end-to-end
relationship, preferably abutting one another, but with no barrier
(other than open air-space) therebetween. The close proximity of
the heat generation segment 35 and the smokable lighting end
segment 22 provides for an appropriate heat exchange relationship
(e.g., such that the action of burning smokable material within the
smokable lighting end segment 22 acts to ignite the heat source of
the heat generation segment 35). The outer cross-sectional shapes
and dimensions of the smokable lighting end and heat generation
segments 22, 35, when viewed transversely to the longitudinal axis
of the smoking article, can be essentially identical to one another
(e.g., both appear to have a cylindrical shape, each having
essentially identical diameters).
[0025] The cross-sectional shape and dimensions of the heat
generation segment 35, prior to burning, can vary. Preferably, the
cross-sectional area of the heat source 40 makes up about 10
percent to about 35 percent, often about 15 percent to about 25
percent of the total cross-sectional area of that segment 35; while
the cross-sectional area of the outer or circumscribing region
(comprising the insulation 42 and relevant outer wrapping
materials) makes up about 65 percent to about 90 percent, often
about 75 percent to about 85 percent of the total cross-sectional
area of that segment 35. For example, for a cylindrical smoking
article having a circumference of about 24 mm to about 26 mm, a
representative heat source 40 has a generally circular
cross-sectional shape with an outer diameter of about 2.5 mm to
about 5 mm, often about 3 mm to about 4.5 mm.
[0026] A longitudinally extending, cylindrical aerosol-generating
segment 51 is located downstream from the heat generation segment
35. The aerosol-generating segment 51 includes a substrate material
55 that, in turn, acts as a carrier for an aerosol-forming agent or
material (not shown). For example, the aerosol-generating segment
51 can include a reconstituted tobacco material that includes
processing aids, flavoring agents and glycerin.
[0027] The foregoing components of the aerosol-generating segment
51 can be disposed within, and circumscribed by, a wrapping
material 58. A wrapping material 58 can be configured to facilitate
the transfer of heat from the lighting end 14 of the smoking
article 10 (e.g., from the heat generation segment 35) to
components of the aerosol-generating segment 51. That is, the
aerosol-generating segment 51 and the heat generation segment 35
can be configured in a heat exchange relationship with one another.
The heat exchange relationship is such that sufficient heat from
the heat source 40 is supplied to the aerosol-formation region to
volatilize aerosol-forming material for aerosol formation. In some
embodiments, the heat exchange relationship is achieved by
positioning those segments in close proximity to one another. A
heat exchange relationship also can be achieved by extending a heat
conductive material from the vicinity of the heat source 40 into or
around the region occupied by the aerosol-generating segment 51.
Particular embodiments of substrates are described below with
reference to FIG. 5.
[0028] A representative wrapping material 58 for the substrate
material 55 may include heat conductive properties to conduct heat
from the heat generation segment 35 to the aerosol-generating
segment 51, in order to provide for the volatilization of the
aerosol forming components contained therein. The substrate
material 55 may be about 10 mm to about 22 mm in length, with
certain embodiments being about 11 mm to about 12 mm in length, and
other embodiments ranging up to about 21 mm.
[0029] The substrate material 55 can be provided from a blend of
flavorful and aromatic tobaccos in cut filler form. Those tobaccos,
in turn, can be treated with aerosol-forming material and/or at
least one flavoring agent. The substrate material can be provided
from a processed tobacco (e.g., a reconstituted tobacco
manufactured using cast sheet or papermaking types of processes) in
cut filler form. Certain cast sheet constructions may include about
270 to about 300 mg of tobacco per 10 mm of linear length. That
tobacco, in turn, can be treated with, or processed to incorporate,
aerosol-forming material and/or at least one flavoring agent, as
well as a burn retardant (e.g., diammonium phosphate or another
salt) configured to help prevent ignition and/or scorching by the
heat-generation segment. A metal inner surface of the wrapping
material 58 of the aerosol-generating segment 51 can act as a
carrier for aerosol-forming material and/or at least one flavoring
agent.
[0030] In other embodiments, the substrate 55 may include a tobacco
paper or non-tobacco gathered paper formed as a plug section. The
plug section may be loaded with aerosol-forming materials,
flavorants, tobacco extracts, or the like in a variety of forms
(e.g., microencapsulated, liquid, powdered). A burn retardant
(e.g., diammonium phosphate or another salt) may be applied to at
least a distal/lighting-end portion of the substrate to help
prevent ignition and/or scorching by the heat-generation
segment.
[0031] In these and/or other embodiments, the substrate 55 may
include marumarized tobacco that has been formed into pellets or
beads. Marumarized tobacco is known, for example, from U.S. Pat.
No. 5,105,831 to Banerjee, et al., which is incorporated herein by
reference. Marumarized tobacco may include about 20 to about 50
percent (by weight) tobacco blend in powder form, with glycerol (at
about 20 to about 30 percent by weight), calcium carbonate (at
about 40 to about 60 percent by weight), along with binder and
flavoring agents. The beads, pellets, or other marumarized forms
may be constructed in dimensions appropriate to fitting within a
substrate section and providing for optimal air flow and production
of desirable aerosol.
[0032] In these or other embodiments, the substrate 55 may include
an open interior section 66 (as shown in FIG. 2). This open region
may allow for aerosol condensation and improved
transport/aerosolization of vaporizable materials being released by
heat during use of the smoking article. The surface of the interior
opening 66 may be coated or otherwise treated with flavorants,
tobacco extracts, or other materials to provide desirable flavors
and/or organoleptic properties to the aerosol traveling
therethrough.
[0033] In still other embodiments, the substrate 55 may include or
be constructed from an extruded material. An extruded substrate may
be formed in the same manner as described herein with reference to
other extruded components. The extruded substrate may include, or
may be essentially comprised of, tobacco, glycerin, water, and
binder material, although certain formulation may exclude binder.
The binder may be any binder commonly used for tobacco formulations
including, for example, CMC (carboxymethyl cellulose) or guar gum,
or it may include diammonium phosphate. In certain embodiments, a
monolithic substrate may include about 10 to about 90
weight-percent tobacco, about 5 to about 50 weight-percent
glycerin, about 1 to about 30 weight-percent water (after drying),
and about 0 to about 10 weight-percent binder.
[0034] In one embodiment, the binder may be a custom binder
designated here as "T-1." The T-1 binder includes tobacco, water,
and diammonium phosphate. Exemplary T-1 formulations may include
about 70 to about 80 percent water (by weight), about 1 to about 5
percent DAP (diammonium phosphate), and about 20 to about 30
percent tobacco. The T-1 may be made by combining those components
in a hot water bath and stirring until a thickened slurry is
formed. The slurry may be dried (e.g., in a vacuum oven), then
ground up and used as a binder.
[0035] For extrusion, the component mix may be loaded into the
barrel of a batch extruder. One end of the barrel preferably will
be fitted with an extrusion die for shaping the extrudate as a
plastic mass. A female extrusion die may be provided with a tapered
surface to facilitate smooth flow of the plastic mass. Such a die
may have, for example, five, seven, ten, or more slots and provide
extrudate readily separable into segments about 5 to about 50 mm in
length and about 0.5 to about 5 mm in diameter, with a mass of
about 50 to about 1000 mg. One or more central steel pins may be
used to provide one or more corresponding central passageways
through the extrudate (e.g., as is shown in FIGS. 6A-6D, below).
Exemplary extruded substrates will have a mass and density
configured to provide a desirable flavor profile and air flow. An
extruded or other monolithic substrate may have zero to about 15
slots on its surface and zero to about 14 longitudinal
holes/channels through its body. A substrate with multiple internal
channels may be extruded with a honeycomb, t-shaped, cross-shaped,
or other cross-sectional geometry. A die pressure of about 3000
lbs. may be used for extrusion. The wet extruded rods preferably
are placed on a well-ventilated tray for approximately one hour,
and may then be carefully cut into lengths of about 5 mm to about
50 mm while preferably preserving the shape of the extrudate and
the integrity of the axial hole(s).
[0036] It should also be appreciated that a substrate may be formed
using the same formulations and components described herein for an
extruded substrate. However, such an alternative embodiment may be
formed by press-fit or molding/casting. Thus, the generic term
"monolithic substrate" is used herein to include a substrate formed
by extrusion or by one of those other methods. Reference to
"extruded substrate" should be interpreted to include press-fit
and/or molded/cast substrates of the same or substantially similar
composition unless contextually excluded.
[0037] For preferred smoking articles, both ends of the
aerosol-generating segment 51 are open to expose the substrate
material 55 thereof. Components of the aerosol produced by burning
the smokable lighting end segment 22 during use of the smoking
article can readily pass through the aerosol-generating segment 51
during draw on the mouth end 18.
[0038] Together, the heat generating segment 35 and the
aerosol-generating segment 51 form an aerosol-generation system 60.
The aerosol-generating segment 51 is positioned adjacent to the
downstream end of the heat generation segment 35 such that those
segments 51, 35 are axially aligned in an end-to-end relationship.
Those segments can abut one another, or be positioned in a slightly
spaced apart relationship, which may include a buffer region 53.
The outer cross-sectional shapes and dimensions of those segments,
when viewed transversely to the longitudinal axis of the smoking
article 10, can be essentially identical to one another. The
physical arrangement of those components preferably is such that
heat is transferred (e.g., by means that includes conductive and
convective heat transfer) from the heat source 40 to the adjacent
substrate material 55, throughout the time that the heat source is
activated (e.g., burned) during use of the smoking article 10.
[0039] A buffer region 53 may reduce potential scorching or other
thermal degradation of portions of the aerosol-generating segment
51. The buffer region 53 may mainly include empty air space, or it
may be partially or substantially completely filled with a
non-combustible material such as, for example, metal, organic,
inorganic, ceramic, or polymeric materials, or any combination
thereof. The buffer regions may be from about 1 mm to about 10 mm
or more in thickness, but often will be about 2 mm to about 5 mm in
thickness.
[0040] The components of the aerosol-generation system 60 and the
smokable lighting end segment 22 preferably are attached to one
another, and secured in place using an overwrap material 64. For
example, the overwrap material 64 can include a paper wrapping
material or a laminated paper-type material that circumscribes each
of the heat generation segment 35, at least a portion of outer
longitudinally extending surface of the aerosol-generating segment
51, and at least a portion of an the lighting end segment 22 that
is adjacent to the heat generation segment. The inner surface of
the overwrap material 64 may be secured to the outer surfaces of
the components it circumscribes by a suitable adhesive. Preferably,
the overwrap material 64 extends over a significant portion of the
length of the smokable lighting end segment 22.
[0041] The smoking article 10 preferably includes a suitable
mouthpiece such as, for example, a filter element 65, positioned at
the mouth end 18 thereof. The filter element 65 preferably is
positioned at one end of the cigarette rod adjacent to one end of
the aerosol-generating segment 51, such that the filter element 65
and the aerosol-generating segment 51 are axially aligned in an
end-to-end relationship, abutting one another but without any
barrier therebetween. Preferably, the general cross-sectional
shapes and dimensions of those segments 51, 65 are essentially
identical to one another when viewed transversely to the
longitudinal axis of the smoking article. The filter element 65 may
include filter material 70 that is overwrapped along the
longitudinally extending surface thereof with circumscribing plug
wrap material 72. In one example, the filter material 70 includes
plasticized cellulose acetate tow, while in some examples the
filter material may further include activated charcoal in an amount
from about 20 to about 80 mg disposed as a discrete charge or
dispersed throughout the acetate tow in a "Dalmatian type" filter.
Both ends of the filter element 65 preferably are open to permit
the passage of aerosol therethrough. The aerosol-generating system
60 preferably is attached to filter element 65 using tipping
material 78. The filter element 65 may also include a crushable
flavor capsule 76 of the type described in U.S. Pat. No. 7,479,098
to Thomas et al. and U.S. Pat. App. Pub. Nos. 2006/0272663 to Dube
et al.; and 2009/0194118 to Ademe et al., which are incorporated
herein by reference in their entirety.
[0042] The smoking article 10 may include an air dilution means,
such as a series of perforations 81, each of which may extend
through the filter element tipping material 78 and plug wrap
material 72 in the manner shown, and/or which may extend to or into
the substrate 55.
[0043] The overall dimensions of the smoking article 10, prior to
burning, can vary. Typically, smoking articles 10 are cylindrically
shaped rods having circumferences of about 20 mm to about 27 mm,
have overall lengths of about 70 mm to about 130 mm--often about 83
mm to about 100 mm. Smokable lighting end segments 22 typically
have lengths of about 3 mm to about 15 mm, but can be up to about
30 mm. The aerosol-generation system 60 has an overall length that
can vary from about 20 mm to about 65 mm. The heat generation
segment 35 of the aerosol-generation system 60 may have a length of
about 5 mm to about 30 mm; and the aerosol-generating segment 51 of
the aerosol-generation system 60 may have an overall length of
about 10 mm to about 60 mm.
[0044] The amount of smokable material 26 employed to manufacture
the smokable lighting end segment 22 can vary. Typically, the
smokable lighting end segment 22, manufactured predominantly from
tobacco cut filler, includes at least about 20 mg, generally at
least about 50 mg, often at least about 75 mg, and frequently at
least 100 mg, of tobacco material, on a dry weight basis. The
packing density of the smokable material 26 within the smokable
lighting end segment 22 preferably will be less than the density of
the fuel element (e.g., about 100 to about 400 mg/cm.sup.3).
Preferably, the smokable lighting end segment 22 essentially
comprises smokable material 26, and does not include a carbonaceous
fuel element component.
[0045] The combined amount of aerosol-forming agent and substrate
material 55 employed in the aerosol-generating segment 51 can vary.
The material preferably may be employed so as to fill the
appropriate section of the aerosol-generating segment 51 (e.g., the
region within the wrapping material 58 thereof) at a packing
density of about 100 to about 400 mg/cm.sup.3.
[0046] During use, the smoker lights the lighting end 14 of the
smoking article 10 using a match or cigarette lighter, in a manner
similar to the way that conventional smoking articles are lit. As
such, the smokable material 26 of the smokable lighting end segment
22 begins to burn. The mouth end 18 of the smoking article 10 is
placed in the lips of the smoker. Thermal decomposition products
(e.g., components of tobacco smoke) generated by the burning
smokable material 26 are drawn through the smoking article 10,
through the filter element 65, and into the mouth of the smoker.
That is, when smoked, the smoking article yields visible mainstream
aerosol that resembles the mainstream tobacco smoke of traditional
cigarettes that burn tobacco cut filler.
[0047] Burning the smokable lighting end segment 22 heats the fuel
element 40 of the heat generation segment 35 such that it
preferably will be ignited or otherwise activated (e.g., begin to
burn). The heat source 40 within the aerosol-generation system 60
will burn, and provide heat to volatilize aerosol-forming material
within the aerosol-generating segment 51 as a result of the heat
exchange relationship between those two segments. Certain preferred
heat sources 40 will not experience volumetric decrease during
activation, while others may degrade in a manner that reduces their
volume. Preferably, the components of the aerosol-generating
segment 51 do not experience thermal decomposition (e.g., charring
or burning) to any significant degree. Volatilized components are
entrained in the air that is drawn through the aerosol-generating
region 51. The aerosol so formed will be drawn through the filter
element 65, and into the mouth of the smoker.
[0048] During certain periods of use, aerosol formed within the
aerosol-generating segment 51, along with the aerosol (i.e., smoke)
formed as a result of the thermal degradation of the smokable
material 26 within the smokable lighting end segment 22, will be
drawn through the filter element 65 and into the mouth of the
smoker, along with the aerosol (i.e., smoke) formed as a result of
the thermal degradation of the smokable material 26 within the
smokable lighting end segment 22. Thus, the mainstream aerosol
produced by the smoking article 10 includes tobacco smoke produced
by the thermal decomposition of the tobacco cut filler as well as
by the volatilized aerosol-forming material. For early puffs (i.e.,
during and shortly after lighting), most of the mainstream aerosol
results from thermal decomposition of the smokable lighting end
segment 22. For later puffs (i.e., after the smokable lighting end
segment 22 has been consumed and the heat source 40 of the
aerosol-generation system 60 has been ignited), most of the
mainstream aerosol that is provided will be produced by the
aerosol-generation system 60. When the smokable material 26 has
been consumed, and the heat source 40 extinguishes, the use of the
smoking article is ceased (i.e., the smoking experience is
finished).
[0049] Referring to FIG. 2, a representative smoking article 10 in
the form of a cigarette is shown. The smoking article 10 includes a
heat generation segment 35 located at the lighting end 14, a filter
segment 65 located at the other end (mouth end 18), and an
aerosol-generating segment 51 (which may incorporate tobacco) that
is located in between those two segments near the lighting end. The
heat generation segment 35 of FIG. 2 can incorporate a generally
cylindrical carbonaceous heat source circumscribed by insulation
similar to what is shown in FIG. 1. The composition and dimensions
of the various segments of the smoking article 10 in FIG. 2 are
generally similar in manner with respect to those set forth
previously with reference to FIG. 1, but without a charge of
smokable material at the distal/lighting end, such that the fuel
element is ignited directly rather than by a smokable material that
was ignited and burned.
[0050] A filter element 65 preferably is attached to the cigarette
rod so formed using a tipping material 78, in the general manner
set forth previously with reference to FIG. 1. The smoking article
optionally can be air-diluted by providing appropriate perforations
81 in the vicinity of the mouth end region 18, as is known in the
art. Filters may include materials and may be manufactured by
methods such as, for example, those disclosed in U.S. Pat. Publ.
Nos. 2008/0029118 to Nelson et al.; 2008/0142028 to Fagg, et al.;
2008/0302373 to Stokes et al.; 2009/028867 to Hutchens et al.; and
2009/009037 to Thomas et al., each of which is incorporated herein
by reference.
[0051] Flavor may be provided or enhanced by capsule or
microcapsule materials on or within the substrate material 55 of
the aerosol-generating segment 51 (FIG. 1 may be considered to have
microcapsules present therein for illustrative purposes), the
wrapping materials, the filter element 65, or any other component
capable of holding and releasing flavorants, preferably with
minimal thermal degradation that would undesirably alter the
flavor. Other flavor components associated with a filter may also
be used; see, for example, U.S. Pat. No. 5,724,997 to Fagg, et
al.
[0052] Cigarettes described with reference to FIG. 2 may be used in
much the same manner as those cigarettes commercially marketed
under the trade name "Eclipse" by R. J. Reynolds Tobacco Company.
See also the "Steam Hot One" cigarette marketed by Japan Tobacco
Inc.
[0053] Smokable materials of the smokable lighting end segment most
preferably incorporate tobacco of some form. Preferred smokable
materials are composed predominantly of tobacco, based on the dry
weights of those materials. That is, the majority of the dry weight
of those materials, and the majority of the weight of a mixture
incorporating those materials (including a blend of materials, or
materials having additives applied thereto or otherwise
incorporated therein) are provided by tobacco of some form. Those
materials may be made all of tobacco material, and not incorporate
any non-tobacco fillers, substitutes or extenders. The smokable
material can be treated with tobacco additives that are
traditionally used for the manufacture of cigarettes, such as
casing and/or top dressing components. These tobacco components may
be understood with reference to the examples and references set
forth in U.S. Pat. App. Pub. No. 2007/0215167 to Crooks, et al.,
which is incorporated herein by reference in its entirety.
[0054] Fuel elements of the heat generation segment may vary.
Suitable fuel elements, and representative components, designs and
configurations thereof, and manners and methods for producing those
fuel elements and the components thereof, are set forth in U.S.
Pat. Nos. 4,714,082 to Banerjee et al.; 4,756,318 to Clearman et
al.; 4,881,556 to Clearman et al.; 4,989,619 to Clearman et al.;
5,020,548 to Farrier et al.; 5,027,837 to Clearman et al.;
5,067,499 to Banerjee et al.; 5,076,297 to Farrier et al.;
5,099,861 to Clearman et al.; 5,105,831 to Banerjee et al.;
5,129,409 to White et al.; 5,148,821 to Best et al.; 5,156,170 to
Clearman et al.; 5,178,167 to Riggs et al.; 5,211,684 to Shannon et
al.; 5,247,947 to Clearman et al.; 5,345,955 to Clearman et al.;
5,469,871 to Barnes et al.; 5,551,451 to Riggs; 5,560,376 to
Meiring et al.; 5,706,834 to Meiring et al.; and 5,727,571 to
Meiring et al.; and U.S. Pat. App. Pub. Nos. 2005/0274390 and
2010/0065075 to Banerjee et al.; which are incorporated herein by
reference.
[0055] Fuel elements often comprise carbonaceous material and may
include ingredients such as graphite or alumina, as well as high
carbon content carbonaceous material. Carbonaceous fuel elements
include the type that have been incorporated within those
cigarettes commercially marketed under the trade names "Premier"
and "Eclipse" by R. J. Reynolds Tobacco Company. See also the
"Steam Hot One" cigarette marketed by Japan Tobacco Inc. Some other
embodiments of fuel elements are set forth in U.S. Pat. Nos.
5,178,167 to Riggs et al. and 5,551,451 to Riggs et al., both which
are incorporated herein by reference in their entirety, but certain
embodiments may lack the sodium, graphite, and/or calcium carbonate
set forth therein. Some fuel element embodiments may include a
foamed carbon monolith. In another embodiment, the fuel element 40
may be co-extruded with a layer of insulation 42, thereby reducing
manufacturing time and expense.
[0056] FIG. 3 shows an example of a carbonaceous fuel element 340
of the type disclosed above with reference to heat source 40. The
following exemplary embodiments are described with reference
thereto, but may be applied to fuel elements having different
geometries and/or underlying compositions.
[0057] In a first embodiment, a fuel element 340 may be dip-coated
with a mixture of two or more precursors. For example, copper
nitrate hemi pentahydrate (available from Alfa Aesar) is mixed with
equal weight of cerium nitrate hexahydrate (available from Alfa
Aesar). The mixture of nitrates may then be dissolved in water (50%
w/w). The fuel element 340 will then be coated with this aqueous
solution, and the coated fuels are dried overnight at about
110.degree. C.
[0058] The treated fuel element 340 is subjected to a heat
treatment under nitrogen in a programmable Barnstead THERMOLYNE
62700 furnace by being heated to about 400.degree. C. at a ramp
rate of about 5.degree. C. per minute and held for about four
hours. The minimum temperatures at which a complete conversion of
cerium nitrate hexahydrate to ceria and conversion of copper
nitrate hemi pentahydrate to copper oxide take place may be
determined by thermo-gravimetric analysis (TGA) using Model STA409
PC analyzer from Netzsch Instruments, Inc. Both transitions
typically take place at or below about 300.degree. C.
[0059] The fuel element 340 may be equilibrated under ambient
conditions and inserted into a cigarette 10 similar in construction
to that shown in FIG. 1. A cigarette 10 thus prepared may be smoked
under 50/30/2 smoking conditions (i.e., 50 ml puffs of 2 second
duration separated by 28 seconds) and CO in the mainstream measured
by nondispersive infrared spectroscopy (NDIR), for example, using
an NGA 2000 from Rosemount Inc. Treatment of the fuel with a
mixture of cerium nitrate hexahydrate and copper nitrate hemi
pentahydrate followed by heat treatment of the fuel will result in
at least about 65% (e.g., about 68%) reduction of mainstream CO as
compared to a control treated only with water. Nicotine and tar
yields of the cigarettes will not be significantly affected by this
modified fuel element. This reduction of CO is believed to result
from a synergistic effect in the catalytic activity of the two
metal oxides. The ratio of copper nitrate hemi pentahydrate and
cerium nitrate hexahydrate may be further optimized for maximum
catalytic activity. In other preparations of similar embodiments,
the fuel element 340 can be dip-coated with the hydrates in
sequence or the hydrates can be applied together or in sequence to
the finished product either drop wise or by dipping the fuel end of
the finished product into the hydrate solution.
[0060] In another embodiment described with reference to making a
fuel element such as, for example, a fuel element 340 shown in FIG.
3, two or more metal nitrates or other metal oxide precursors may
be mixed and dissolved in water. The solution may then be applied
to graphite. The treated graphite may then be dried and calcined to
yield metal-oxide coated graphite. Proper selection of metal oxides
and processing conditions may yield synergistic catalytic activity.
In variant embodiments of this application, the precursor solutions
can be added sequentially to graphite, i.e. one metal nitrate
solution is added to the graphite, dried and calcined as described
before to convert the metal nitrate to metal oxide. The resulting
metal oxide coated graphite may then be impregnated with a second
metal oxide precursor solution followed by drying and
calcination.
[0061] In yet another embodiment described with reference to making
a fuel element such as, for example, a fuel element 340, about 7.5
grams of cerium (III) nitrate hexahydrate (available from Alfa
Aesar) and about 7.5 grams of copper (II) nitrate hemi pentahydrate
(available from Alfa Aesar) may be dissolved in about 7 ml of
water. Next, about 18 grams of graphite powder (available Superior
Graphite Inc.) may be impregnated with the metal nitrate solution
and dried overnight in air. The treated graphite may then be
calcined at about 300.degree. C. for about one hour under a
nitrogen atmosphere in, for example, a programmable Barnstead
THERMOLYNE 62700 furnace, where the ramp rate may be set at about
5.degree. C./minute. Calcination will lead to decomposition of both
the metal nitrates to their respective metal oxides.
[0062] The metal oxide-coated graphite may then be ground in a
pestle mortar and combined with about 72 grams of milled BKO carbon
powder (available from Barnaby and Suttcliffe), and about 10 grams
of guar gum. Further mixing may be done in, for example, a Sigma
blade mixer (Teledyne) for about an hour at a low speed. Water may
then be added to convert the powder into plastic dough by mixing
for about two additional hours. Sufficient water preferably will be
added to ensure that the plastic mix is stiff enough to hold its
shape after extrusion. The moisture content of the dough at this
stage will typically be about 42 to 43% (w/w). The dough preferably
will be aged overnight in a sealed container at room
temperature.
[0063] For extrusion, the plastic mix may be loaded into the barrel
of a batch extruder. One end of the barrel preferably will be
fitted with an extrusion die for shaping the extrudate. A female
extrusion die may be provided with a tapered surface to facilitate
smooth flow of the plastic mass. Such a die may have, for example,
five or seven slots and be about 4.2 mm in diameter. An optional
central steel pin may be used to provide a central passageway
through the extrudate (e.g., as is shown in FIGS. 4B-4C, below). A
die pressure of about 3000 lbs. may be used for extrusion. The wet
extruded rods preferably are placed on a well-ventilated tray for
approximately one hour, and may then be carefully cut into about 12
mm lengths while preferably preserving the shape of the extrudate
and the integrity of the axial hole. The cut fuel rods 340 may then
be dried overnight at about room temperature. A cigarette 10
constructed using this embodiment and smoked under 60/30/2 smoking
conditions may provide mainstream aerosol having its CO reduced by
at least about 50% (for example, about 56%), compared to a
cigarette with an untreated control fuel element.
[0064] Addition of metal oxide precursor solution to graphite
occasionally may result in agglomeration of the metal oxide on the
graphite surface, leading to reduced catalytic activity. Such
agglomeration is believed due to the relatively low surface area
and hydrophobic nature of the graphite surface. Adding carbon to
graphite before impregnation with precursor solution will minimize
agglomeration of the metal oxide and result in a higher catalytic
activity. In another embodiment, about 18 grams of graphite may be
mixed with about 18 grams of milled BKO carbon. About 15 grams of
copper nitrate hemi-penta-hydrate will be dissolved in about 7.5 ml
of water. The mixture of graphite and carbon may then uniformly be
impregnated with the copper nitrate solution and dried overnight at
room temperature. The coated carbon-graphite mixture may thereafter
be calcined at about 300.degree. C. for one hour under a nitrogen
atmosphere. Fuel elements may be extruded and cut as described
earlier. Cigarettes made with this metal nitrate-treated,
carbon-graphite mixture will produce about 50% less CO in the
mainstream smoke than a control cigarette using an untreated fuel
element.
[0065] Compared to graphite, BKO milled carbon has a large surface
area and consequently has a large adsorption capacity for the metal
oxide catalyst precursor solution. This results in a highly uniform
dispersion of the solution with minimum agglomeration of the metal
oxide and thus a good activity of the metal oxide catalyst.
[0066] In still another embodiment, about 7.5 grams of copper
nitrate hemi pentahydrate may be dissolved in 7 grams of water.
About 18 grams of BKO milled carbon is impregnated with the
solution and the mixture is dried overnight at room temperature.
The treated carbon is calcined at about 300.degree. C. for one hour
under nitrogen atmosphere. The calcined carbon is mixed with other
fuel ingredients and is extruded into fuel rods as described
before. A cigarette prepared with this fuel will have about a 50%
reduction in mainstream CO compared to cigarettes produced with
untreated fuel elements. In addition, cigarettes produced with the
treated milled carbon fuel may be easier to light than cigarettes
produced with fuel made with precursor-treated graphite described
above.
[0067] The carbonaceous fuel elements commonly in use typically are
extruded with a binder that is mostly organic in nature. Some
commonly used binders include ammonium alginate, carboxymethyl
cellulose, ethyl cellulose and guar gum. These binders provide good
flow characteristics and improved physical and mechanical
properties for processing the extrudate. However, upon combustion
the extruded fuel may produce volatile organic compounds that
negatively influence the taste, aroma, and chemistry of the smoke.
These volatile organic compounds may nearly be eliminated if the
extruded fuel is calcined prior to its use in the cigarette.
[0068] Accordingly, certain fuel embodiments may be extruded,
having been formed using (by weight) about 30% calcium carbonate,
about 10% guar gum, about 10% copper nitrate-treated graphite, and
about 50% carbon. Treatment of graphite with catalyst precursor and
the process of extrusion may be conducted as described above. The
extruded fuel may be calcined at about 500.degree. C. for about two
hours under nitrogen atmosphere. In test cigarettes constructed
with the calcined fuels no significant impact was observed on the
yields of tar, nicotine and carbon monoxide of the cigarette but
significant improvements were noted with regard to taste and aroma
of the mainstream and side stream smoke.
[0069] The fuel element preferably will be circumscribed or
otherwise jacketed by insulation, or other suitable material. The
insulation can be configured and employed so as to support,
maintain and retain the fuel element in place within the smoking
article. The insulation may additionally be configured such that
drawn air and aerosol can pass readily therethrough. Examples of
insulation materials, components of insulation assemblies,
configurations of representative insulation assemblies within heat
generation segments, wrapping materials for insulation assemblies,
and manners and methods for producing those components and
assemblies, are set forth in U.S. Pat. Nos. 4,807,809 to Pryor et
al.; 4,893,637 to Hancock et al.; 4,938,238 to Barnes et al.;
5,027,836 to Shannon et al.; 5,065,776 to Lawson et al.; 5,105,838
to White et al.; 5,119,837 to Banerjee et al.; 5,247,947 to
Clearman et al.; 5,303,720 to Banerjee et al.; 5,345,955 to
Clearman et al.; 5,396,911 to Casey, III et al.; 5,546,965 to
White; 5,727,571 to Meiring et al.; 5,902,431 to Wilkinson et al.;
and 5,944,025 to Cook et al.; which are incorporated herein by
reference. Insulation assemblies have been incorporated within the
types of cigarettes commercially marketed under the trade names
"Premier" and "Eclipse" by R. J. Reynolds Tobacco Company, and as
"Steam Hot One" cigarette marketed by Japan Tobacco Inc.
[0070] FIGS. 4A-4G show different embodiments of insulation and
fuel elements of a heat generation segment. In certain embodiments,
the insulation layer may include about 40 to about 50 percent (by
weight) flue-cured tobacco lamina, about 20 to about 25 percent (by
weight) water-soluble flue-cured tobacco stems extract, and about
20 to about 25 percent (by weight) wood pulp. In certain
embodiments, the layer may include about 20 percent (by weight)
carbon fiber, or about 20 percent (by weight) c-glass fiber.
Preferred insulation layers thus formed include a treatment of
about 5 to about 15 percent ammonium chloride (NH.sub.4Cl), or of a
50/50 mixture of about 5 percent NH.sub.4Cl and 5 percent sodium
bicarbonate, by which is meant that the compound(s) will be present
on the insulation layer sheet(s). These and other flame-retardants
may be used in varying amounts. The insulation thus formed may be
manufactured on a standard fourdrinier paper-making machine.
Preferred insulation layer sheets thus formed will include a
porosity of about 50 to about 150 cfm, a basis weight of about 80
to about 150 gsm, and a tensile strength of about 2000 to about
3000 gsm.
[0071] An insulation layer 42 may include an inner-facing geometry
configured to engage and longitudinally retain a heat source 40.
The engagement may be accomplished by a compression fit,
co-extrusion of heat-source and insulation materials, or other
methods known or developed in the art. Preferred heat sources
include those that experience little if any volumetric decrease
during a smoking activity. Certain heat sources may degrade and
shrink longitudinally and/or circumferentially after being ignited,
but--for preferred embodiments incorporating complementarily-shaped
insulation elements--heat source embodiments including a matrix or
other composition that generally retains volume after ignition are
preferable.
[0072] FIGS. 4A-4B show, respectively, an end view of an insulation
material 442 and heat source 440, and a perspective view of the
heat source 440 without the insulation material 442. These elements
are configured to interlockingly engage with a dovetail connection,
where the inward-facing surface insulation material 442 includes an
inward-facing geometry with a flared tongue protrusion 442c
configured to engage in dovetail fashion with a
complementarily-shaped flared groove 440c in an outward-facing
recessed groove geometry of the heat source 440. The outward-facing
geometry of the heat source 440 includes generally elongate rounded
grooves 440d configured to facilitate airflow. In one embodiment,
the dovetail groove 440c will be only one-half as wide at its
narrowest portion (at the top/edge of the outer heat source
surface) as it is at the groove's widest portion. It should be
appreciated that the flared tongue and groove may be constructed in
variant fashion, by--for example--reversing the relative position
of the dovetailed elements, orienting them other than
longitudinally, and/or providing other interengaging tongue/groove
geometries.
[0073] FIGS. 4C-4D show, respectively, an end view of a heat source
740, and a longitudinal section view of the heat source 740 with
the insulation material 742. These elements are configured to
interlockingly engage, with the insulation forming a retaining lip
or shoulder 742a at the lighting end 714. That is, the
inward-facing surface of the insulation material 742 includes an
inward-facing geometry with a protrusion 742a configured to engage
around a complementarily-shaped lighting end decreased-diameter
cylindrical segment 740a of the heat source 740. The outward-facing
geometry of the heat source 740 may include generally elongate
rounded exterior grooves 740d that are configured to facilitate
airflow. A heat source 740 may include one or more generally
central longitudinal channels 741.
[0074] FIGS. 4E-4F show, respectively, a perspective view of a
generally frustoconical heat source 840, and a longitudinal section
view of the heat source 840 with an insulation material 842. These
elements are configured to engage, with the inward-facing geometry
of the insulation 842 forming a generally frustoconical space that
houses and complementarily fits the heat source 840. The
outward-facing geometry of the heat source 840 may include
generally elongate rounded exterior grooves 840d that are
configured to facilitate airflow. In many embodiments, five to
eight such grooves may provide a desired airflow. This and other
embodiments may include features described with reference only in
various other embodiments herein. For example, a heat source 840
may include one or more generally central longitudinal channels
841.
[0075] FIG. 4G shows a longitudinal section view of the heat source
940 with an insulation material 942. These elements are configured
to engage, with the inward-facing geometry of the insulation 942
forming a generally columnar space that houses and complementarily
fits the heat source 940. The heat source 940 includes a flared
base 940e opposite the lighting end 914 that is configured to
longitudinally retain it within the insulation 942.
[0076] In one specific example, an insulation material may be
constructed including about 50 percent (by weight) flue-cured
tobacco lamina, about 25 percent (by weight) water-soluble
flue-cured tobacco stems extract, and about 25 percent (by weight)
wood pulp. After being formed into a sheet, the material may be
treated with about 5 to about 15 percent ammonium chloride
(NH.sub.4Cl), or of a 50/50 mixture of about 5 percent NH.sub.4Cl
and 5 percent sodium bicarbonate. The insulation material may be
manufactured as a sheet on a standard fourdrinier paper-making
machine. The sheet insulation may include a porosity of about 50 to
about 150 cfm, a basis weight of about 80 to about 150 gsm, and a
tensile strength of about 2000 to about 3000 gsm.
[0077] In another example, an insulation material may be
constructed including about 40 percent (by weight) flue-cured
tobacco lamina, about 20 percent (by weight) water-soluble
flue-cured tobacco stems extract, about 20 percent (by weight) wood
pulp, and about 20 percent (by weight) c-glass fiber. After being
formed into a sheet, the material may be treated with about 5 to
about 15 percent ammonium chloride (NH.sub.4Cl), or of a 50/50
mixture of about 5 percent NH.sub.4Cl and 5 percent sodium
bicarbonate. The insulation material may be manufactured as a sheet
on a standard fourdrinier paper-making machine. The sheet
insulation may include a porosity of about 50 to about 150 cfm, a
basis weight of about 80 to about 150 gsm, and a tensile strength
of about 2000 to about 3000 gsm.
[0078] In still another example, an insulation material may be
constructed including about 40 percent (by weight) flue-cured
tobacco lamina, about 20 percent (by weight) water-soluble
flue-cured tobacco stems extract, about 20 percent (by weight) wood
pulp, and about 20 percent (by weight) carbon fiber. After being
formed into a sheet, the material may be treated with about 5 to
about 15 percent ammonium chloride (NH.sub.4Cl), or of a 50/50
mixture of about 5 percent NH.sub.4Cl and 5 percent sodium
bicarbonate. The insulation material may be manufactured as a sheet
on a standard fourdrinier paper-making machine. The sheet
insulation may include a porosity of about 50 to about 150 cfm, a
basis weight of about 80 to about 150 gsm, and a tensile strength
of about 2000 to about 3000 gsm.
[0079] Flame/burn retardant materials and additives useful in
insulation may include silica, carbon, ceramic, metallic fibers
and/or particles. When treating cellulosic or other fibers such
as--for example--cotton, boric acid or various organophosphate
compounds may provide desirable flame-retardant properties. In
addition, various organic or metallic nanoparticles may confer a
desired property of flame-retardancy, as may diammonium phosphate
and/or other salts. Other useful materials may include
organo-phosphorus compounds, borax, hydrated alumina, graphite,
potassium tripolyphosphate, dipentaerythritol, pentaerythritol, and
polyols. Others such as nitrogenous phosphonic acid salts,
mono-ammonium phosphate, ammonium polyphosphate, ammonium bromide,
ammonium chloride, ammonium borate, ethanolammonium borate,
ammonium sulphamate, halogenated organic compounds, thio-urea, and
antimony oxides may be used but are not preferred agents. In each
embodiment of flame-retardant, burn-retardant, and/or
scorch-retardant materials used in insulation, substrate material
and other components (whether alone or in any combination with each
other and/or other materials), the desirable properties most
preferably are provided without undesirable off-gassing or
melting-type behavior.
[0080] An insulation fabric made by any one of the above processes
preferably will have sufficient oxygen diffusion capability to
sustain a smoking article such as a cigarette lit during a desired
usage time. Accordingly the insulation fabric preferably will be
porous by virtue of its construction. In knit, woven, or combined
woven and knit constructions, the required porosity may be
controlled by configuring the assembly machinery to leave
sufficient (desirably sized) gaps between fibers to allow for
oxygen diffusion into the heat source. For non-woven fabrics, which
may not be porous enough to promote evenly sustained combustion,
additional porosity may be achieved by perforations into the
insulation by methods known in the art including, for example, hot
or cold pin perforation, flame perforation, embossing, laser
cutting, drilling, blade cutting, chemical perforation, punching,
and other methods. Each of the buffer and the insulation may
include non-glass material that is woven, knit, or a combination
thereof, a foamed metal material, a foamed ceramic material, a
foamed ceramic metal composite, and any combination thereof, and
the material in the insulation may be the same as or different than
that in the buffer.
[0081] The aerosol-forming material can vary, and mixtures of
various aerosol-forming materials can be used, as can various
combinations and varieties of flavoring agents (including various
materials that alter the sensory and/or organoleptic character or
nature of mainstream aerosol of a smoking article), wrapping
materials, mouth-end pieces, filter elements, plug wrap, and
tipping material. Representative types of these components are set
forth in U.S. Pat. App. Pub. No. 2007/0215167 to Crooks, et al.,
which is incorporated herein by reference in its entirety.
[0082] The substrate material can incorporate tobacco of some form,
normally is composed predominantly of tobacco, and can be provided
by virtually all tobacco material. The form of the substrate
material can vary. In some embodiments, the substrate material is
employed in an essentially traditional filler form (e.g., as cut
filler). The substrate material can be otherwise formed into
desired configurations. The substrate material can be used in the
form of a gathered web or sheet, using the types of techniques
generally set forth in U.S. Pat. No. 4,807,809 to Pryor et al,
which is incorporated herein by reference in its entirety. The
substrate material can be used in the form of a web or sheet that
is shredded into a plurality of longitudinally extending strands,
using the types of techniques generally set forth in U.S. Pat. No.
5,025,814 to Raker, which is incorporated herein by reference in
its entirety. The substrate material can have the form of a loosely
rolled sheet, such that a spiral type of air passageway extends
longitudinally through the aerosol-generating segment.
Representative types of tobacco containing substrate materials can
be manufactured from mixtures of tobacco types; or from one
predominant type of tobacco (e.g., a cast sheet-type or paper-type
reconstituted tobacco composed primarily of burley tobacco, or a
cast sheet-type or paper-type reconstituted tobacco composed
primarily of Oriental tobacco).
[0083] The substrate material also can be treated with tobacco
additives of the type that are traditionally used for the
manufacture of cigarettes, such as casing and/or top dressing
components. See, for example, the types of components set forth in
U.S. Pat. Publication 2004/0173229 to Crooks et al, which is
incorporated herein by reference in its entirety.
[0084] The manner by which the aerosol-forming material is
contacted with the substrate material (e.g., the tobacco material)
can vary. The aerosol-forming material can be applied to a formed
tobacco material, or can be incorporated into processed tobacco
materials during manufacture of those materials. The
aerosol-forming material can be dissolved or dispersed in an
aqueous liquid, or other suitable solvent or liquid carrier, and
sprayed onto that substrate material. See, for example, U.S. Patent
Application Pub. No. 2005/0066986 to Nestor et al, which is
incorporated herein by reference in its entirety. The amount of
aerosol-forming material employed relative to the dry weight of
substrate material can vary. Materials including exceedingly high
levels of aerosol-forming material can be difficult to process into
cigarette rods using conventional types of automated cigarette
manufacturing equipment.
[0085] Cast sheet types of materials may incorporate relatively
high levels of aerosol-forming material. Reconstituted tobaccos
manufactured using paper-making types of processes may incorporate
moderate levels of aerosol-forming material. Tobacco strip and
tobacco cut filler can incorporate lower amounts of aerosol-forming
material. Various paper and non-paper substrates including
gathered, laminated, laminated metal/metallic, strips, beads such
as alumina beads, open cell foam, foamed monolith, air permeable
matrices, and other materials can be used within the scope of the
invention. See, for example, U.S. Pat. Nos. 5,183,062; 5,203,355;
and 5,588,446; each to Clearman, and each of which is incorporated
herein by reference.
[0086] In one embodiment, the substrate may be constructed in a
novel multilayer fashion not including cast sheet construction,
discussed here with reference to FIG. 5, which is a longitudinal
section view of a cigarette 510 having a lighting end 514 and a
mouth end 518. The substrate 555 (which may be used in other
embodiment such as, for example, those discussed with reference to
FIG. 1 and FIG. 2) includes a multilayer construction that
preferably is stitch-bonded together.
[0087] A generally cylindrical or other-shaped substrate core 563
may be centrally located in the substrate 555. The core 563 may
include fabric (which may be treated with glycerin), and may also
include an open longitudinal channel 566. A first outer layer 593
may be disposed coaxially around (i.e., generally encircling) the
substrate core 563. The first outer layer 593 may be constructed
including a fabric material such as, for example cotton or rayon.
The fabric material preferably has been treated with glycerin such
that the glycerin is absorbed into the fabric, which may also
include one or more flame-retardant, burn-retardant, and or
scorch-retardant agents. The first outer layer 593 may be
constructed as a plurality of layers including a multilayer
construction with two or more layers.
[0088] An intermediate layer 592 may be disposed generally
coaxially/concentrically around the first outer layer 593. The
intermediate layer 592 is constructed as a layer of aromatic
tobacco paper 592. The tobacco paper may be treated with flavoring
agents, including those known for use in treating cut tobacco,
tobacco papers, and generally within the tobacco art, as well as
agents that may yet be developed. Preferred flavoring agents will
help provide a mainstream aerosol including desirable flavor and
aroma. A second outer layer 591 may be disposed coaxially around
the intermediate layer 592. Like the first outer layer 593, the
second outer layer may be constructed as a plurality of layers
including a multilayer construction with two or more layers. And,
it may be constructed of fabric material that preferably has been
treated with glycerin such that the glycerin is absorbed into the
fabric, which may also include one or more flame-retardant,
burn-retardant, and or scorch-retardant agents.
[0089] At least a portion of the first outer layer 593, second
outer layer 591, and/or intermediate layer 592 preferably will be
stitch-bonded together using a substrate heat-conducting material
such as, for example, a metallic material (including as one
example, aluminum). Stitch-bonding is known in the art of making
non-woven fabrics (e.g., using barbed needles to entangle or
otherwise bond fibers together to form a non-woven fabric or web).
A stitch-bonding process may be used to form a three-layered
substrate (e.g., as shown diagrammatically in FIG. 5) including at
least one first outer layer 593, at least one intermediate layer
592, and at least one second outer layer 591 by joining one or more
portions of two or more of the layers together. The heat-conducting
material will help transmit heat from the heat-generation segment
535 in a matter configured to generate a desirable aroma and flavor
from the substrate 555. This construction may be superior to cast
sheet substrates, which may experience scorching and/or introduce
undesirable flavors, tastes, aromas, etc. The presence of glycerin
and the layered construction described with reference to the
embodiment of FIG. 5 will help reduce scorching and minimize
undesirable flavors and/or aromas associated with scorching.
Embodiments with this and other substrate embodiments may be used
with cigarettes including smokable material at the lighting end
(e.g., as in FIG. 1).
[0090] In still other embodiments, the substrate portion of an
aerosol-generation segment may include or may be constructed from
an extruded or other monolithic material. An extruded substrate may
be formed in the same manner as described herein with reference to
other extruded components. The extruded or other monolithic
substrate may include, or may be essentially comprised of, tobacco,
glycerin, water, and binder material. In certain embodiments, a
monolithic substrate may include about 10 to about 90
weight-percent tobacco, about 5 to about 50 weight-percent
glycerin, about 1 to about 30 weight-percent water (before being
dried and cut), and about 0 to about 10 weight-percent binder. It
may also include a filler such as, for example, calcium carbonate
and/or graphite.
[0091] For extrusion, the component mix may be loaded into the
barrel of a batch extruder. One end of the barrel preferably will
be fitted with an extrusion die for shaping the extrudate as a
plastic mass. A female extrusion die may be provided with a tapered
surface to facilitate smooth flow of the plastic mass. Such a die
may have, for example, one, five, seven, ten, or more (or fewer)
slots and provide for extrudate with about 5 to about 10 mm outer
diameter, although the outer diameter may be larger and the
substrate may not necessarily have a circular cross-section. One or
more central steel pins may be used to provide one or more
corresponding central passageways, which may include up to 14 or
more such passages through the extrudate (e.g., as is shown in
FIGS. 6A-6D, discussed below). The passages may be circular and/or
polygonal in cross section, including providing a monolithic
substrate having a generally honeycomb cross-sectional
appearance.
[0092] Exemplary extruded and other monolithic substrates will have
a mass and density configured to provide a desirable flavor profile
and air flow. A monolithic substrate may have zero to at least one
to about 15 slots/grooves on its exterior surface and zero to about
14 longitudinal holes/channels through its body. Certain preferred
embodiments may include at least one generally centered passage
that is about 0.025 to about 0.1 inches in diameter. Generally, the
passages may have internal diameters of less than 0.001 to about
0.1 inches. A substrate with multiple internal channels may be
extruded with a honeycomb geometry. A die pressure of about 3000
lbs. may be used for extrusion. The wet extruded rods preferably
are placed on a well-ventilated tray for approximately one hour,
and may then be carefully cut into lengths of about 5 mm to about
50 mm while preferably preserving the shape of the extrudate and
the integrity of the axial hole(s). The dried weight of the
substrate units may range from about 50 to about 1000 mg.
[0093] Following extrusion, drying, and cutting to a desired
length, the substrate may be assembled into a segmented smoking
article such as an Eclipse-type cigarette using a manual assembly
method or a cigarette-making machine (e.g., KDF or Protus by Hauni
Maschinenbau AG). Smaller diameter monolithic substrate elements
may be combined by being wrapped, adhered, or otherwise assembled
together for use in a smoking article as described for other
substrate embodiments herein. Preferred substrate wraps include
foil paper, heavy-gauge paper, plug wrap, and/or cigarette
paper.
[0094] FIG. 6A shows a generally cylindrical slotted/grooved
monolithic substrate element 600 including a plurality of external
grooves 602. FIG. 6B shows a grooved monolithic substrate element
610 including a plurality of external grooves 612 and a center hole
614 that extends longitudinally through its length. As shown in
FIGS. 6A-6B, the grooves/slots do not have to be the same shape(s)
as each other. FIG. 6C shows a generally cylindrical non-grooved
monolithic substrate element 620 including a center-hole 624 (it
should be appreciated that the "center-hole" may actually be
off-center in certain embodiments). FIG. 6D shows a non-grooved
monolithic substrate element 630 including a center-hole 634 and a
plurality of holes/channels 636 configured in a honeycomb-like
manner and extending through its length.
[0095] In one embodiment, a smoking article may be constructed with
an monolithic substrate 763, described here with reference to FIG.
7, which is a longitudinal section view of a cigarette 710 having a
lighting end 714 and a mouth end 718. The monolithic substrate 763
(which may be used in other embodiments such as, for example, those
discussed with reference to FIGS. 1, 2, and 5) may be formed by any
appropriate extrusion method and is shown with a center-hole 795
extending longitudinally therethrough. The monolithic substrate,
cut to length may comprise about 1/16 to about 5/8 of the total
length of the cigarette, often about 1/10 to about 1/2 thereof
(e.g., a 10 mm, 12 mm, or 50 mm long substrate element in an 85 mm
or 130 mm long cigarette). The substrate segment 755 of the
cigarette body includes a hollow spacing tube 767 disposed between
the substrate 767 and the filter 770. The filter 770 is shown as
constructed with overlying layers of plug wrap 772 and tipping
paper 778. The substrate 763 and tube 767 are surrounded by a
wrapping material 758, which may be configured--for example--as a
heat-conducting material (e.g., foil paper), heavy-gauge paper,
plug wrap, or cigarette paper. A cylindrically-encompassing
wrapping material 764 (such as, for example, cigarette paper or
heavy-gauge paper) may be provided to connect the heat-generation
segment 735, central substrate segment 755, and filter segment 765.
The heat-generation segment 735 and other components may be
constructed as described herein and elsewhere in this and other
embodiments configured to be practiced within the scope of the
present invention.
[0096] In another embodiment, a smoking article may be constructed
with an elongate monolithic substrate 863, described here with
reference to FIG. 8, which is a longitudinal section view of a
cigarette 810 having a lighting end 814 and a mouth end 818. The
elongate monolithic substrate 863 (which may be used in other
embodiments) may be formed by any appropriate extrusion method and
is shown with a center-hole 895 extending longitudinally
therethrough. The filter 870 is shown as constructed with overlying
layers of plug wrap 872 and tipping paper 878. The substrate 863 is
surrounded by a wrapping material 858, which may be configured--for
example--as a heat-conducting material (e.g., foil paper),
heavy-gauge paper, plug wrap, or cigarette paper. A
cylindrically-encompassing wrapping material (such as, for example,
cigarette paper or heavy-gauge paper) may be provided to connect
the heat-generation segment 835, central substrate segment 855
(consisting essentially of the substrate in this embodiment), and
filter segment 865. The heat-generation segment 835 and other
components may be constructed as described herein and elsewhere in
this and other embodiments configured to be practiced within the
scope of the present invention.
[0097] In one embodiment, a smoking article may be constructed with
an monolithic substrate 963, described here with reference to FIG.
9, which is a longitudinal section view of a cigarette 910 having a
lighting end 914 and a mouth end 918. The monolithic substrate 963
(which may be used in other embodiments) may be formed by any
appropriate extrusion method and is shown with a center-hole 995
extending longitudinally therethrough. The cigarette body includes
a tobacco rod 969 disposed between the substrate 967 and the filter
970. The filter 970 is shown as constructed with overlying layers
of plug wrap 972 and tipping paper 978. The substrate segment 955,
formed by the substrate 963 and tobacco rod 969, is surrounded by a
wrapping material 958, which may be configured--for example--as a
heat-conducting material (e.g., foil paper), heavy-gauge paper,
plug wrap, or cigarette paper. A cylindrically-encompassing
wrapping material (such as, for example, cigarette paper or
heavy-gauge paper) may be provided to connect the heat-generation
segment 935, central substrate segment 955, and filter segment 965.
The heat-generation segment 935 and other components may be
constructed as described herein and elsewhere in this and other
embodiments configured to be practiced within the scope of the
present invention.
[0098] In other embodiments, an extruded or other monolithic
substrate may be used in place of the substrates discussed herein
with reference, for example, to FIGS. 1 and 2. For example, in one
embodiment, the substrate 55 of FIG. 1 may be replaced with a
monolithic substrate having one or more internal longitudinal
channels and/or one or more external grooves. Various other filter
designs may be used including perforated filters made of
non-cellular acetate materials known in the art, as well as other
filter configurations now known or forthcoming, all within the
scope of the present invention. The other portions of cigarettes
made with extruded or other monolithic substrates may also be
modified in accordance with the state of the art, and still be
practiced within the scope of the present invention. In the
following examples, the monolithic substrate includes about 20 to
about 60 weight-percent tobacco, about 20 to about 35
weight-percent glycerin, about 1 to about 20 weight-percent water,
and about 1 to about 4 weight-percent binder.
Example 1
Extruded Substrate in Smoking Article
[0099] In one example, smoking articles of about 83-85 mm in length
were constructed using a heat source of about 12 mm in length, a
substrate extruded according to the processes described herein and
measuring about 10 mm in length, a hollow/void tube between the
substrate and filter measuring about 50 mm in length, and a
cellulose acetate filter about 10 mm in length. The exemplary
extruded substrate was formed with ten external slots and a 0.032
inch center-hole, and it included the following components:
TABLE-US-00001 Component Mass (g) Weight-Percent Flue-Cured Tobacco
15 11.8% Burley Tobacco 9 7.1% Turkish Tobacco 6 39.4% CaCo.sub.3
50 39.4% Glycerin 40 31.5% CMC (binder) 2 1.6% Water 5 3.9%
The physical construction of the smoking article of Example 1 may
be understood with reference to the construction of the cigarette
710 shown in FIG. 7.
Example 2
Extruded Substrate in Smoking Article
[0100] In another example, a smoking article was constructed using
a heat source of about 12 mm in length, a substrate extruded
according to the processes described herein and measuring about 50
mm in length, and a cellulose acetate filter about 10 mm in length
with minimal space between the substrate and the filter. The
exemplary extruded substrate was formed with ten external slots and
a 0.032 inch center-hole, and it included the following
components:
TABLE-US-00002 Component Mass (g) Weight-Percent Flue-Cured Tobacco
50 14.4% Burley Tobacco 30 8.6% Turkish Tobacco 20 5.8% CaCo.sub.3
100 28.8% Glycerin 80 23.1% CMC (binder) 12 3.5% Water 55 15.9%
The physical construction of the smoking article of Example 2 may
be understood with reference to the construction of the cigarette
810 shown in FIG. 8.
Example 3
Extruded Substrate in Smoking Article
[0101] In another example, a smoking article was constructed using
a heat source of about 12 mm in length, a substrate extruded
according to the processes described herein and measuring about 10
mm in length, a tobacco rod between the substrate and filter
measuring about 50 mm in length, and a cellulose acetate filter
about 10 mm in length. The exemplary extruded substrate was formed
with ten external slots and a 0.032 inch center-hole, and it
included the following components:
TABLE-US-00003 Component Mass (g) Weight-Percent Flue-Cured Tobacco
15 11.8% Burley Tobacco 9 7.1% Turkish Tobacco 6 4.7% CaCo.sub.3 50
39.4% Glycerin 40 31.5% CMC (binder) 2 1.6% Water 5 3.9%
The physical construction of the smoking article of Example 3 may
be understood with reference to the construction of the cigarette
910 shown in FIG. 9.
Example 4
Extruded Substrate in Smoking Article
[0102] In another example, a smoking article was constructed using
a heat source of about 12 mm in length, a substrate extruded
according to the processes described herein and measuring about 50
mm in length, and a cellulose acetate filter about 10 mm in length
with minimal space between the substrate and the filter. The
exemplary extruded substrate was formed with ten external slots and
a 0.032 inch center-hole, and it included the following
components:
TABLE-US-00004 Component Mass (g) Weight-Percent Flue-Cured Tobacco
100 28.8% Burley Tobacco 60 17.3% Turkish Tobacco 40 11.5%
CaCo.sub.3 0 0% Glycerin 80 23.1% CMC (binder) 12 3.5% Water 55
15.9%
The physical construction of the smoking article of Example 4 may
be understood with reference to the construction of the cigarette
810 shown in FIG. 8.
Example 5
Extruded Substrate in Smoking Article
[0103] In another example, a smoking article was constructed using
a heat source of about 12 mm in length, a substrate extruded
according to the processes described herein and measuring about 50
mm in length, and a cellulose acetate filter about 10 mm in length
with minimal space between the substrate and the filter. The
exemplary extruded substrate was formed with ten external slots and
a 0.032 inch center-hole, and it included the following
components:
TABLE-US-00005 Component Mass (g) Weight-Percent Flue-Cured Tobacco
100 28.0% Burley Tobacco 60 16.8% Turkish Tobacco 40 11.2% Graphite
10 2.8% Glycerin 80 22.4% CMC (binder) 12 3.4% Water 55 15.4%
The physical construction of the smoking article of Example 5 may
be understood with reference to the construction of the cigarette
810 shown in FIG. 8.
Examples 6 and 7
Substrates with T-1 Binder
[0104] In another example, two substrates were formed according to
processes described herein, and they included the following
components:
TABLE-US-00006 Mass (q) Mass (q) Component (Example 6) (Example 7)
Tobacco 150 80 T-1 Binder (formed as 50 50 73.2 wt-pct water; 3.6%
wt-pct DAP; and 23.2% wt-pct tobacco Glycerin 80 80 Water 45 55
CaCO.sub.3 -- 70
Examples 8 and 9
Substrates with DAP
[0105] In another example, two substrates may be formed by
combining the following components in a heated mixer, then being
extruded, press-fit, or molded/cast. The substrates may include the
following mixtures of components:
TABLE-US-00007 Weight-Percent Weight-Percent Component (Example 8)
(Example 9) Tobacco 59.5% 36.8% DAP 2.1% 2.0% Glycerin 24.6% 23.9%
Water 13.8% 16.4% CaCO.sub.3 -- 20.9%
[0106] Cigarettes of the present invention may be air-diluted or
ventilated such that the amount of air dilution for an air diluted
cigarette may be about 10 percent to about 80 percent. As used
herein, the term "air dilution" is the ratio (expressed as a
percentage) of the volume of air drawn through the air dilution
means to the total volume of air and aerosol drawn through the
cigarette and exiting the mouth end portion of the cigarette.
Higher air dilution levels can act to reduce the transfer
efficiency of aerosol-forming material into mainstream aerosol.
[0107] Preferred embodiments of cigarettes of the present
invention, when smoked, yield an acceptable number of puffs. Such
cigarettes normally provide more than about 6 puffs, and generally
more than about 8 puffs, per cigarette, when machine-smoked under
standardized smoking conditions. Such cigarettes normally provide
less than about 15 puffs, and generally less than about 12 puffs,
per cigarette, when smoked under standardized smoking conditions.
Standardized smoking conditions consist of 35 ml puffs of 2 second
duration separated by 58 seconds of smolder.
[0108] Aerosols that are produced by cigarettes of the present
invention are those that comprise air-containing components such as
vapors, gases, suspended particulates, and the like. Aerosol
components can be generated from burning tobacco of some form (and
optionally other components that are burned to generate heat); by
thermally decomposing tobacco caused by heating tobacco and
charring tobacco (or otherwise causing tobacco to undergo some form
of smolder); and by vaporizing aerosol-forming agent. As such, the
aerosol can contain volatilized components, combustion products
(e.g., carbon dioxide and water), incomplete combustion products,
and products of pyrolysis.
[0109] Aerosol components may also be generated by the action of
heat from burning tobacco of some form (and optionally other
components that are burned to generate heat), upon substances that
are located in a heat exchange relationship with tobacco material
that is burned and other components that are burned. Aerosol
components may also be generated by the aerosol-generation system
as a result of the action of the heat generation segment upon an
aerosol-generating segment. In some embodiments, components of the
aerosol-generating segment have an overall composition, and are
positioned within the smoking article, such that those components
will have a tendency not to undergo a significant degree of thermal
decomposition (e.g., as a result of combustion, smoldering or
pyrolysis) during conditions of normal use.
[0110] Drawings in the figures illustrating various embodiments are
not necessarily to scale. Some drawings may have certain details
magnified for emphasis, and any different numbers or proportions of
parts should not be read as limiting, unless so-designated by one
or more claims. Those of skill in the art will appreciate that
embodiments not expressly illustrated herein may be practiced
within the scope of the present invention, including that features
described herein for different embodiments may be combined with
each other and/or with currently-known or future-developed
technologies while remaining within the scope of the claims
presented here. It is therefore intended that the foregoing
detailed description be regarded as illustrative rather than
limiting. And, it should be understood that the following claims,
including all equivalents, are intended to define the spirit and
scope of this invention.
* * * * *