BACKGROUND
[0001] As part of efforts to reduce the incidence of accidental fires resulting from untended
smoking articles, various jurisdictions have imposed, are imposing, and may impose
in the future limitations on the burning characteristics of smoking articles. One
measure of the tendency of a smoking article to cause ignition of an underlying substrate
is the Ignition Propensity value. To meet common governmental requirements, the Ignition
Propensity value, or IP value, for a smoking article should preferably be no greater
than about 25%, when tested in accordance with ASTM E2187. More preferably, the IP
value should be no greater than about 20%, and even more preferably no greater than
about 10%. Accordingly, efforts to meet such limits are undertaken by various manufacturers
of smoking articles.
SUMMARY
[0002] According to an example disclosed herein, a smoking article includes a tobacco rod
comprising a column of filler and a wrapper surrounding the column of filler. The
tobacco rod has a circumferential direction, a longitudinal direction, a lit end,
and a mouth end. The wrapper includes a base web having generally parallel first and
second side edges extending in the longitudinal direction and two ends extending in
the circumferential direction wherein the base web is disposed around the column of
filler such that the first and second side edges of the base web overlap and form
a seam. The base web includes at least one circumferentially extending banded region
of fibrous crystalline cellulosic material thereon. The fibrous crystalline cellulosic
material is in a condition of having been gravure printed on the base web as a fibrous
crystalline cellulosic slurry that comprises water, crystalline cellulose, and chalk
wherein the fibrous crystalline cellulosic slurry has a solids content of about 10%
or less by weight of the fibrous crystalline cellulosic slurry.
[0003] According to an example disclosed herein, a wrapper for smoking articles includes
a base web having generally parallel first and second side edges extending in a longitudinal
direction, two ends extending in a transverse direction, and a plurality of longitudinally
spaced banded regions of fibrous crystalline cellulosic material thereon, the fibrous
crystalline cellulosic material having been gravure printed on the base web as a fibrous
crystalline cellulosic slurry comprising water, crystalline cellulose, and chalk wherein
the fibrous crystalline cellulosic slurry has a solids content of about 10% or less
by weight of the fibrous crystalline cellulosic slurry.
[0004] According to an example disclosed herein, a method of making banded wrapper paper
for smoking articles includes advancing a base web to a first printing station and
printing a first layer of a fibrous crystalline cellulosic slurry on the base web.
The fibrous crystalline cellulosic slurry includes water, crystalline cellulose, and
chalk and has a solids content of about 10% or less by weight of the fibrous crystalline
cellulosic slurry. The printing includes applying the fibrous crystalline cellulosic
slurry to a patterned gravure roller, and contacting the advancing base web with the
patterned gravure roller to apply bands of the fibrous crystalline cellulosic slurry
on the base web. Banded regions of fibrous crystalline cellulosic material are formed
on the base web by drying the bands of the fibrous crystalline cellulosic slurry.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005]
FIG. 1 is an example embodiment of a smoking article having banded wrapper paper as
described herein.
FIG. 2 is a schematic view of an example embodiment of banded wrapper paper as described
herein.
FIG. 3 is a schematic view of an example gravure printing process suitable for producing
embodiments of banded wrapper paper as described herein.
FIG. 4 is an illustration of an example embodiment of a gravure cylinder as described
herein.
FIGS. 5A, 5B, and 5C are illustrations of an example embodiment of a gravure cylinder
etching process.
FIG. 6 is a schematic view of an example embodiment of banded wrapper paper as described
herein.
FIG. 7 is an illustration of an example embodiment of a gravure cylinder as described
herein.
DETAILED DESCRIPTION
[0006] Referring to FIG. 1, a smoking article 120, such as a cigarette, can comprise a tobacco
rod 122 and a filter 132 attached to one end of the tobacco rod 122 with tipping paper
129. The tobacco rod 122 comprises a column of shredded tobacco ("cut filler") and
a piece of banded wrapper paper 123 disposed about the column of shredded tobacco.
[0007] The tobacco rod 122 has a lightable or lit end 124 and a tipped end 130, which, in
the case of non-filtered cigarettes, is referenced as the mouth end 130 of the smoking
article 120. Cut filler tobacco is an industry-standard designation. In an example
embodiment, the tobacco rod 122 has a generally circular cross section. In other example
embodiments, the tobacco rod 122 can have an oval cross section or other non-circular
shape cross section. The wrapper 123 is sealed along a longitudinal seam to form the
tobacco rod 122.
[0008] The smoking article 120 has a nominal length measured from the edge 131 of the tipping
paper to the lit end 124 of the tobacco rod 122 along a longitudinal axis of smoking
article 120. By way of example, that nominal length may lie in the range of about
60 to about 100 mm.
[0009] As shown in FIG. 2, the banded wrapper paper 123 can include a base web 140 that
may be made from flax, wood pulp, cellulose fiber, or the like. In an example embodiment,
the base web 140 has a plurality of bands of fibrous crystalline cellulosic material
126 on one or both sides thereof. In an example embodiment, the bands of fibrous crystalline
cellulosic material 126 are applied to a wire side of the base web 140 such that they
are on the inside of the banded wrapper paper 123 when a piece of the wrapper 123
surrounds a column of shredded tobacco to form a tobacco rod 122.
[0010] In the manufacture of base web 140 suited for the construction of the various embodiments
of banded wrapper paper disclosed herein, such manufacture usually will include the
production of a roll of base web 140 of several feet across (usually about 3 feet
to about 5 feet across or in transverse dimension), which is then slit into ribbons
that are wound on bobbins. Printing operations are conducted on the rolls, but could
be conducted after slitting. The bobbins themselves will have a transverse dimension
equivalent to the width needed to make tobacco rods 122 or an integral number of such
widths (e.g., 1, 2, or 4 of such widths). The bobbins are adapted for use with typical
cigarette making machines. In an example embodiment, the banded wrapper paper has
a dimension in cross-direction that takes into account the nominal circumference of
the tobacco rod 122 and an overlapping seam. As a result, when the banded wrapper
paper 123 is slit, the smoking article 120 formed therefrom always has a longitudinal
seam with an exact overlap.
[0011] For purposes of this disclosure, "longitudinal" refers to the direction along the
length of a tobacco rod 122 (e.g., along the axis 134 in FIG. 1), or along the length
of a base web 140 (e.g., arrow 142 in FIGs. 2 and 6) used in the preparation of banded
wrapper paper 123 that, in turn, may be used to fabricate a tobacco rod 122.
[0012] For purposes of this disclosure, "transverse" refers to the direction circumferentially
around a tobacco rod 122 (see FIG. 1) or the direction perpendicular to the length
of the base web 140 (e.g., arrow 144 in FIGs. 2 and 6) used in the preparation of
banded wrapper paper 123 that, in turn, may be used to fabricate a tobacco rod 122.
[0013] For purposes of this disclosure, a "band" or "banded region" 126 is an area (see
FIG. 2) on an underlying base web 140 to which a fibrous crystalline cellulosic slurry
has been printed to form a region of fibrous crystalline cellulosic material. As used
herein, the phrase "leading edge" refers to the edge 146 (see FIG. 1) of a banded
region 126 that is closest to an approaching coal during smoldering of a smoking article
120 whose wrapper 123 contains the banded region 126, while the phrase "trailing edge"
refers to the edge 148 of a banded region 126 that is farthest from an approaching
coal during smoldering of a smoking article 120 whose wrapper 123 contains the banded
region 126. As used herein, "band spacing" refers to the distance between the trailing
edge 148 of one banded region 126 and the leading edge 146 of an adjacent banded region
126 on the base web 140 from which banded wrapper paper 123 is fashioned. As used
herein, "phase" refers to the distance from the leading edge 146 of one banded region
126 to the leading edge 146 of an adjacent banded region 126.
[0014] In an example embodiment, the banded regions of fibrous crystalline cellulosic material
126 extend transversely across the base web 140 and are separated by regions free
of added fibrous crystalline cellulosic material in the longitudinal direction 142
of the base web 140. The banded regions of fibrous crystalline cellulosic material
126 are applied to the base web 140 of the banded wrapper paper 123 to obtain satisfactory
or improved Ignition Propensity ("IP") characteristics for a smoking article including
a piece of the banded wrapper paper 123 and optionally to also obtain improved Self-Extinguishment
("SE") characteristics for the smoking article.
[0015] In an example embodiment, the banded regions of fibrous crystalline cellulosic material
126 are arranged on the base web 140 such that at least one banded region of fibrous
crystalline cellulosic material 126 is positioned between the lit end 124 and the
tipped end 130 of the tobacco rod 122 in each finished smoking article 120 that includes
the banded wrapper paper 123. In an example embodiment, at least two banded regions
of fibrous crystalline cellulosic material 126 are positioned between the lit end
124 and the tipped end 130 of the tobacco rod 122 in each finished smoking article
120 that includes the banded wrapper paper 123. In an example embodiment, the banded
regions of fibrous crystalline cellulosic material 126 extend circumferentially around
the tobacco rod at one or more longitudinally spaced locations along the axis 134
thereof.
[0016] It is noted for sake of convention that, in describing dimensions of various embodiments
herein, that band or banded region "width" extends in a longitudinal direction along
axis 142 of the base web 140 (see FIG. 2) or axis 134 of the tobacco rod 122, whereas
a dimension in the circumferential direction will be expressed as "circumferential"
or "transverse" or "in cross-direction."
[0017] In an example embodiment, where the banded regions of fibrous crystalline cellulosic
material 126 extend transversely across the base web 140 (or circumferentially around
a tobacco rod 122), the "width" of the banded regions of fibrous crystalline cellulosic
material 126 is measured in the longitudinal direction 142 from a leading edge 146
to a trailing edge 148 thereof. In an example embodiment, the widths of the banded
regions of fibrous crystalline cellulosic material 126 are each about 5 to about 9
mm (from the leading edge 146 to the trailing edge 148). In an example embodiment,
the widths of the banded regions of fibrous crystalline cellulosic material 126 are
each about 5.5 to about 7.5 mm. In an example embodiment, the widths of the banded
regions of fibrous crystalline cellulosic material 126 are each about 6 to about 7
mm. In an example embodiment, adjacent banded regions of fibrous crystalline cellulosic
material 126 are longitudinally spaced by regions of the base web 140 free of added
fibrous crystalline cellulosic material by a distance of about 20 mm to about 30 mm.
In an example embodiment, the phase (i.e., the spacing from the leading edge 146 of
one banded region 126 to the leading edge 146 of an adjacent banded region 126) is
about 25 mm or 27 mm. While the banded regions of fibrous crystalline cellulosic material
126 are depicted in this disclosure as solid bands, other configurations of the banded
regions 126 on the base web 140 are within the spirit and scope of this disclosure,
including, but not limited to, configurations in which the banded regions 126 have
one or more areas free of added fibrous crystalline cellulosic material between the
leading and trailing edges 146, 148 thereof.
[0018] The base web 140 of the banded wrapper paper 123 is permeable to air. Permeability
of the base web 140 is typically identified in CORESTA units. A CORESTA unit measures
paper permeability in terms of volumetric flow rate (i.e., cm
3/sec) per unit area (i.e., cm
2) per unit pressure drop (i.e., cm of water). In example embodiments, the base web
140 of the banded wrapper paper 123 has a permeability of at least about 20 CORESTA
units and a basis weight of about 22 to 30 gram(s) per square meter in regions outside
of the banded regions of fibrous crystalline cellulosic material 126. In this specification,
the unit of measurement for basis weight, gram(s) per square meter, is abbreviated
as "gsm". In example embodiments, the base web 140 of the banded wrapper paper 123
has a permeability of at least about 20 CORESTA units and a basis weight of about
25 to 27 gsm in regions outside of the banded regions of fibrous crystalline cellulosic
material 126. In an example embodiment, the base web 140 of the wrapper 123 has a
permeability greater than about 30 CORESTA in regions outside of the banded regions
of fibrous crystalline cellulosic material 126. In an example embodiment, the base
web 140 of the wrapper 123 has a permeability of about 33 CORESTA with a basis weight
of about 25 gsm in regions outside of the banded regions of fibrous crystalline cellulosic
material 126. In an example embodiment, the base web 140 of the wrapper 123 has a
permeability of about 46 CORESTA with a basis weight of about 25 gsm in regions outside
of the banded regions of fibrous crystalline cellulosic material 126. In an example
embodiment, the base web 140 of the wrapper 123 has a permeability of about 60 CORESTA
in regions outside of the banded regions of fibrous crystalline cellulosic material
126. In an example embodiment, the base web 140 of the wrapper 123 has a permeability
of about 60 CORESTA with a basis weight of about 25 gsm in regions outside of the
banded regions of fibrous crystalline cellulosic material 126. In an example embodiment,
the base web 140 of the wrapper 123 has a permeability of about 60 CORESTA with a
basis weight of about 26 gsm in regions outside of the banded regions of fibrous crystalline
cellulosic material 126. In example embodiments, the base web 140 has a permeability
greater than about 60 CORESTA with a basis weight of about 25 gsm or more, a permeability
greater than about 80 CORESTA with a basis weight of about 25 gsm or more, or a permeability
greater than about 100 CORESTA with a basis weight of about 25 gsm or more in regions
outside of the banded regions of fibrous crystalline cellulosic material 126.
[0019] In example embodiments, application of the fibrous crystalline cellulosic slurry
to a base web 140 and drying thereof, forms a banded region of fibrous crystalline
cellulosic material 126 on the base web 140 that is effective to locally reduce the
permeability of the base web 140 within the banded region 126. In example embodiments,
bands of fibrous crystalline cellulosic slurry are printed on the base web 140 with
a gravure roller 610 to reduce the permeability of the base web 140 within the banded
regions of fibrous crystalline cellulosic material 126 to about 0 to about 12 CORESTA.
In an example embodiment, the permeability of the base web 140 within the banded regions
of fibrous crystalline cellulosic material 126 is 7 CORESTA or less.
[0020] In example embodiments, application of the fibrous crystalline cellulosic slurry
to the base web 140 and drying thereof, forms a banded region of fibrous crystalline
cellulosic material 126 on the base web 140 that is effective to locally reduce diffusivity
values of the base web 140 from a diffusivity level of about 2 cm/sec or greater (for
the base web 140 in regions free of added fibrous crystalline cellulosic material)
to a value in the range of 0.0 to about 0.2 cm/sec as measured by a Sodim CO
2 Diffusivity Tester (purchased from Sodim SAS of France). To measure the diffusivity
of a piece of banded wrapper paper 123 using a Diffusivity Tester, the banded wrapper
paper 123 is positioned within a clamping head so that the banded wrapper paper 123
separates two vertically arranged chambers. The upper chamber contains a carrier gas,
such as nitrogen, while the lower chamber contains a marker gas, such as carbon dioxide.
There is no pressure difference between the two chambers such that there is no permeability
effect, which occurs when a pressure difference is maintained between two surfaces
of the banded wrapper paper 123. As such, any migration of gases between the two chambers
is due to differences in concentrations of the gases. After a predetermined period
of time (e.g., for about 25 seconds or less), the concentration of carbon dioxide
within the nitrogen stream of the upper chamber is measured in an analyzer. A computer
then converts the detected level of concentration into a measure of diffusivity. In
an example embodiment, the diffusivity of the base web 140 within the banded regions
of fibrous crystalline cellulosic material 126 is less than about 0.15 cm/sec. In
an example embodiment, the diffusivity of the base web 140 within the banded regions
of fibrous crystalline cellulosic material 126 is about 0 to about 0.1 cm/sec (e.g.
about 0.01 to about 0.09 cm/sec, about 0.02 to about 0.08 cm/sec, about 0.03 to about
0.07 cm/sec or about 0.04 to about 0.06 cm/sec).
[0021] As used herein, "layer" refers to a quantity of fibrous crystalline cellulosic slurry
printed on the base web 140 by a gravure roller from which banded wrapper paper 123
is fabricated. In an example embodiment, each banded region of fibrous crystalline
cellulosic material 126 may be formed by gravure printing a "layer" of a fibrous crystalline
cellulosic slurry on the base web 140 to reduce the permeability of the base web 140
in the corresponding banded region. In an example embodiment, the fibrous crystalline
cellulosic slurry is aqueous.
[0022] To form the banded regions of fibrous crystalline cellulosic material 126, a single
pass or multi-pass gravure printing process can be utilized. Alternatively, multiple
pass gravure printing can be utilized. FIG. 3 is a schematic view of a single stage
printing apparatus 602. With reference to the above-description for printing, a supply
reel 601 supplies a blank base web 140 to a gravure printing station 602 where a banded
region of fibrous crystalline cellulosic slurry is printed on the blank base web 140
by the gravure roller 610 and dried in a drier 634. In an example embodiment, the
drier 634 can include at least one steam can. In an example embodiment, the drier
634 can include two steam cans wherein the base web 140 is advanced and pressed between
the steam cans to reduce wrinkling of the base web 140. The dried, patterned base
web 140 then advances to a collection reel 608. If desired, a wide base web 140 may
be slit or divided by a slitter 635 into a plurality of narrower strips of base web
that may be wound to form individual bobbins after the printing operation, where the
bobbins have a width corresponding to that required for a smoking article 120. The
optional slitter 635 may be used on the base web 140 as that base web 140 leaves the
printing station, or the slitter and slitting operation may be conducted at a different
location.
[0023] Example embodiments of gravure printing the fibrous crystalline cellulosic slurry
as disclosed herein enable high-speed printing on the base web 140. For purposes of
this disclosure, "high-speed" printing refers to printing processes where the base
web 140 advances through the printing process at a linear speed greater than about
300 feet/min. In an example embodiment, the size of the crystalline fibers in the
fibrous crystalline cellulosic slurry, and the deposition rate and viscosity of the
fibrous crystalline cellulosic slurry are selected such that base web printing speeds
of greater than 500 feet/minute can be achieved.
[0024] As shown in FIG. 4, the gravure cylinder (roller) 610 includes a plurality of cells
700 arranged in a pattern corresponding to a band that is to be printed on the base
web 140 by the gravure roller 610. In an example embodiment, the gravure cylinder
610 includes two or more circumferentially spaced regions 701 of cells 700 wherein
each region 701 of cells 700 is arranged in a pattern corresponding to a band that
is to be printed on the base web 140 by the gravure roller 610. In this embodiment,
adjacent regions 701 of cells 700 are circumferentially spaced by cell free surfaces
703 of the gravure roller 610 which extend a distance corresponding to the spacing
between adjacent banded regions to be printed on the base web 140. In an embodiment,
the pattern of cells 700 corresponding to banded regions are arranged in a chevron
pattern wherein angle "A" at the tip or apex of the chevron is preferably greater
than about 170 degrees. Such arrangement helps distribute stress due to shrinkage
in the base web 140 upon application of the fibrous crystalline cellulosic slurry
and drying, which in turn, helps alleviate the tendency of the paper to pucker or
wrinkle in the course of gravure printing operations.
[0025] In an example embodiment, as shown in FIGS. 5A, 5B, and 5C, the cells of the gravure
roller 610 can be formed by etching the gravure roller 610. Suitable etching processes
and gravure cylinders can be obtained from Heliograph Holding GmbH. In an example
embodiment, photoresist 801 is applied to a metallic surface 800, and lasers 802 are
used to activate the photoresist, which serves to mask areas where walls are desired.
In an example embodiment, as shown in FIG. 4, the gravure roller 610 (shown in FIG.
4) has a plurality of cells 700 which have a generally hexagonal shape. In an example
embodiment, the cells 700 of the gravure roller 610 can have walls 702 ranging from
about 12 to about 80 microns in width between adjacent cells 700 depending on the
desired final volume of each cell 700. In an example embodiment, the cells 700 of
the gravure roller 610 can have walls 702 ranging from about 12 to about 20 microns
in width between adjacent cells 700. In an example embodiment, the gravure cylinder
610 can be formed such that certain cells within a region of cells are thinner than
walls of other cells of the gravure roller 610. In an example embodiment, the cells
700 of the gravure roller 610 can have a generally circular shape. In an example embodiment,
the depth of the cells 700 is uniform. However, in other embodiments, the depth of
the cells 700 can vary.
[0026] In use, the cells 700 are filled with the fibrous crystalline cellulosic slurry such
that they may print the fibrous crystalline cellulosic slurry on the base web 140.
In an example embodiment, the cells 700 are sized to print dots of the fibrous crystalline
cellulosic slurry which spread to form a continuous band of fibrous crystalline cellulosic
material 126 on the base web 140 when the fibrous crystalline cellulosic slurry is
dried. In an example embodiment, the cells 700 are sized to print dots of the fibrous
crystalline cellulosic slurry to form a substantially continuous band of fibrous crystalline
cellulosic material 126 on the base web 140 when the fibrous crystalline cellulosic
slurry is dried. In an example embodiment, the cells 700 are sized to print small
enough dots of the fibrous crystalline cellulosic slurry to form a non-continuous
band of fibrous crystalline cellulosic material 126 on the base web 140 when the fibrous
crystalline cellulosic slurry is dried wherein one or more areas within the non-continuous
band of fibrous crystalline cellulosic material 126 are free of added fibrous crystalline
cellulosic material. Adjustment of diffusivity of the banded regions of fibrous crystalline
cellulosic material 126 can be facilitated by changing the size and/or number of cells
700 which apply fibrous crystalline cellulosic slurry.
[0027] In the printing station 602, a gravure roller 610 is supplied fibrous crystalline
cellulosic slurry, and moves through a doctor blade 630 that extends along the length
of the gravure roller 610. The doctor blade 630 is positioned so that is wipes the
surface of the gravure roller 610 such that portions 703 of the gravure roller 610
that define the nominal spacing between adjacent banded regions 126 are essentially
wiped clean of the fibrous crystalline cellulosic slurry, while the cells 700 of the
gravure roller 610 advance toward a nip 616 of the printing station 602 full of the
fibrous crystalline cellulosic slurry. The gravure roller 610 contacts one side of
the base web 140 in the nip 616 between the gravure roller 610 and an impression cylinder
612 backed by backing roller 614 to print the fibrous crystalline cellulosic slurry
in the cells of the gravure roller 610 on the base web 140. In an example embodiment,
the fibrous crystalline cellulosic slurry is delivered from a reservoir 618 to an
applicator 624 by a suitable pump 620. The fibrous crystalline cellulosic slurry is
spread on the gravure roller 610 by the applicator 624. Excess fibrous crystalline
cellulosic slurry accumulates in a bath 626 held by collector 627 from which excess
fibrous crystalline cellulosic slurry returns via drain 628 to the reservoir 618.
In an example embodiment, the fibrous crystalline cellulosic slurry is continuously
circulated between the reservoir 618 and the bath 626 to prevent the solids in the
fibrous crystalline cellulosic slurry from settling in the bottom of the reservoir
618 or the bottom of the bath 626. In an example embodiment, the fibrous crystalline
cellulosic slurry in the reservoir 618 is continuously agitated or mixed, to prevent
solids in the fibrous crystalline cellulosic slurry from settling in the bottom of
the reservoir 618. In an embodiment, the fibrous crystalline cellulosic slurry printed
on the base web 140 at room temperature. In an embodiment, the fibrous crystalline
cellulosic slurry printed on the base web 140 at a temperature less than about 38°
C.
[0028] In an example embodiment, the fibrous crystalline cellulosic slurry can be prepared
by mixing fibrous crystalline cellulosic material and chalk with a sufficient amount
of water to make an aqueous slurry having a composition of less than about 10% solids.
In an example embodiment, the fibrous crystalline cellulosic material is insoluble
in the water such that mixing the fibrous crystalline cellulosic material and chalk
with the water suspends the fibrous crystalline cellulosic material and the chalk
in the water to form a stable slurry. In an example embodiment, the fibrous crystalline
cellulosic material is free of any modified cellulose. In an example embodiment, the
fibrous crystalline cellulosic material is free of any binders. In an example embodiment,
the fibrous crystalline cellulosic material is free of any binders and modified cellulose.
In an example embodiment, the fibrous crystalline cellulosic material is free of any
bacterial cellulose. In an example embodiment, the fibrous crystalline cellulosic
material is microcrystalline cellulose and is free of any binders and modified cellulose.
In an example embodiment, the fibrous crystalline cellulosic material is microcrystalline
cellulose and a binder.
[0029] In an example embodiment, the fibrous crystalline cellulosic material includes microcrystalline
cellulose and a binder, and is free of any modified cellulose. In an example embodiment,
the fibrous crystalline cellulosic material is free of starch, guar gum, alginate,
and/or cellulose derivatives. In an example embodiment, the fibrous crystalline cellulosic
material is free of any film forming material. In an example embodiment, the fibrous
crystalline cellulosic material includes a binder such as sodium carboxymethyl cellulose
or carboxymethyl cellulose. In an example embodiment, the fibrous crystalline cellulosic
material includes microcrystalline cellulose and a binder wherein the binder is less
than about 9% by weight of the fibrous crystalline cellulosic material.
[0030] In an example embodiment, the fibrous crystalline cellulosic material includes AVICEL
™ microcrystalline cellulose. In an example embodiment, the fibrous crystalline cellulosic
material includes microcrystalline cellulose and a binder, and is free of any modified
cellulose. In an example embodiment, the fibrous crystalline cellulosic material includes
microcrystalline cellulose wherein the fibers of the microcrystalline cellulose are
predominately of a size of about 200 microns or less. In an example embodiment, the
fibrous crystalline cellulosic material includes microcrystalline cellulose wherein
at least 90% of the fibers of the microcrystalline cellulose have a size of about
200 microns or less. In an example embodiment, the fibrous crystalline cellulosic
material includes microcrystalline cellulose wherein the fibers of the microcrystalline
cellulose are predominately of a size of about 10 microns or more.
[0031] In an example embodiment, the fibrous crystalline cellulosic material is insoluble
in room temperature water wherein the fibrous crystalline cellulosic material is mixed
with room temperature water. In an embodiment, the fibrous crystalline cellulosic
material is insoluble in water having a temperature less than about 38° C wherein
the fibrous crystalline cellulosic material is mixed with water having a temperature
less than about 38° C. In an example embodiment, the fibrous crystalline cellulosic
material and chalk is mixed with non-deionized water such as tap water. In an example
embodiment, the fibrous crystalline cellulosic slurry is a composition having less
than about 9.5% fibrous crystalline cellulosic material and less than about 5.5% chalk.
In an example embodiment, the fibrous crystalline cellulosic slurry is a composition
having about 9.5% fibrous crystalline cellulosic material and about 5.5% chalk. In
an example embodiment, the fibrous crystalline cellulosic slurry includes up to 9.5
weight % cellulosic fibrous crystalline material and up to 5.5 weight % chalk. In
an embodiment, a room temperature viscosity of the fibrous crystalline cellulosic
slurry is no greater than about 40 centipoises. In an example embodiment, a room temperature
viscosity of the fibrous crystalline cellulosic slurry is between about 30 to 40 centipoises.
In an embodiment, a room temperature viscosity of the fibrous crystalline cellulosic
slurry is less than about 30 to 40 centipoises.
[0032] In an example embodiment, the fibrous crystalline cellulosic slurry is a composition
having less than about 10% solids wherein a ratio fibrous crystalline cellulosic material
to chalk in the fibrous crystalline cellulosic slurry is about 95 to 5. In an example
embodiment, the fibrous crystalline cellulosic slurry is a composition having less
than about 8% solids wherein a ratio fibrous crystalline cellulosic material to chalk
in the fibrous crystalline cellulosic slurry is about 95 to 5. In an example embodiment,
the fibrous crystalline cellulosic slurry is a composition having less than about
6% solids wherein a ratio fibrous crystalline cellulosic material to chalk in the
fibrous crystalline cellulosic slurry is about 95 to 5. In an embodiment, the fibrous
crystalline cellulosic slurry is a composition having less than about 5% solids wherein
a ratio fibrous crystalline cellulosic material to chalk in the fibrous crystalline
cellulosic slurry is about 95 to 5. In an embodiment, the fibrous crystalline cellulosic
slurry is a composition having about 2% solids wherein a ratio fibrous crystalline
cellulosic material to chalk in the fibrous crystalline cellulosic slurry is about
95 to 5. In an embodiment, the fibrous crystalline cellulosic slurry is a composition
having less than about 10% solids wherein a ratio fibrous crystalline cellulosic material
to chalk in the fibrous crystalline cellulosic slurry is about 94.5 to 5.5. In an
embodiment, the fibrous crystalline cellulosic slurry is a composition having less
than about 8% solids wherein a ratio fibrous crystalline cellulosic material to chalk
in the fibrous crystalline cellulosic slurry is about 94.5 to 5.5. In an embodiment,
the fibrous crystalline cellulosic slurry is a composition having less than about
6% solids wherein a ratio fibrous crystalline cellulosic material to chalk in the
fibrous crystalline cellulosic slurry is about 94.5 to 5.5. In an embodiment, the
fibrous crystalline cellulosic slurry is a composition having less than about 5% solids
wherein a ratio fibrous crystalline cellulosic material to chalk in the fibrous crystalline
cellulosic slurry is about 94.5 to 5.5. In an embodiment, the fibrous crystalline
cellulosic slurry is a composition having about 2% solids wherein a ratio fibrous
crystalline cellulosic material to chalk in the fibrous crystalline cellulosic slurry
is about 94.5 to 5.5.
[0033] In an embodiment, the final fibrous crystalline cellulosic slurry can be printed
as longitudinally spaced apart banded regions, as described with respect to FIG. 2,
to a base web 140 used to form banded wrapper paper 123 for smoking articles wherein
the base web 140 has a nominal width ranging from about 36 inches (i.e., about 920
mm) to about 60 inches at the gravure printing press. In an embodiment, the moisture
content of the base web 140 at the time of gravure printing is at least 3%. In an
embodiment, the base web 140 is passed through a sprayer operable to spray water on
the base web 140 before gravure printing to increase the moisture level of the base
web 140 to at least 3%.
[0034] In an embodiment, the fibrous crystalline cellulosic slurry can be applied to the
base web 140 at a target rate of about 5 to 50 BCM (billion cubic microns per square
inch). In an embodiment, the fibrous crystalline cellulosic slurry can be applied
to the base web 140 at a target rate of about 5 BCM to about 38 BCM. Thereafter the
base web 140 can be dried so that the printing solution dries. In an example embodiment,
the fibrous crystalline cellulosic slurry is gravure printed on the base web 140 in
a single pass to form bands of fibrous crystalline cellulosic material 126 wherein
the total dry weight of the added fibrous crystalline cellulosic material of each
band is up to about 2.5 gsm. In an example embodiment, the fibrous crystalline cellulosic
slurry is gravure printed on the base web 140 in a single pass to form bands of fibrous
crystalline cellulosic material 126 wherein the total dry weight of the added fibrous
crystalline cellulosic material of each band is about 2.5 gsm. In an example embodiment,
the fibrous crystalline cellulosic slurry is gravure printed on the base web 140 in
multiple passes to form bands having multiple layers of fibrous crystalline cellulosic
material 126 wherein the total dry weight of the added fibrous crystalline cellulosic
material is up to about 2.5 gsm. In an example embodiment, the fibrous crystalline
cellulosic slurry is gravure printed on the base web 140 in multiple passes to form
bands having multiple layers of fibrous crystalline cellulosic material 126 wherein
the total dry weight of the added fibrous crystalline cellulosic material is about
2.5 gsm. In an example embodiment wherein the fibrous crystalline cellulosic slurry
is gravure printed on the base web 140 in multiple passes, the base web 140 may be
passed through a drier 634, such as a heated can drier, to dry or partially dry the
base web 140 between passes.
[0035] Once printed, the base web 140 can be passed through the drier 634 and advanced under
tension to a slitter 635 where the nominal width of the base web can be longitudinally
cut into a plurality of strips or ribbons, each strip having a width of about 27 mm
(e.g., the width required to surround a conventional tobacco rod and have a longitudinal
glue seam). While the base web 140 is still under tension, the plurality of strips
can be simultaneously wound onto individual bobbins.
[0036] Ignition Propensity or IP is a standard test conducted as set forth in ASTM E 2187-04,
"Standard Test Method for Measuring the Ignition Strength of Smoking Articles", which
is incorporated herein in its entirety by this reference thereto. Ignition propensity
measures the probability that a smoking article, when smoldering and placed on a substrate,
will generate sufficient heat to maintain smoldering of the tobacco rod. Low values
for IP are desirable as such values correlate with a reduced likelihood that a smoldering
smoking article, when inadvertently left unattended upon a substrate, will cause combustion
in the substrate. An IP value of a smoking article should be no greater than about
25%, and preferably no greater than about 20%, and even more preferably no greater
than about 10% as described in
US Patent Application Publication No. 2013/0306082 published Nov. 21, 2013, the entire content of which is incorporated herein by reference thereto.
[0037] Self-Extinguishment or SE herein is a reference to smoldering characteristics of
a smoking article under free burn conditions. To evaluate SE, a laboratory test is
conducted at a temperature of 23° C +- 0.3° C and relative humidity of 55% +- 0.5%,
both of which should be monitored by a recording hygrothermograph. Exhaust hood(s)
remove combustion products formed during testing. Prior to testing, smoking articles
to be tested are conditioned at 55% +-0.5% relative humidity and 23° C +- 0.3° C for
24 hours. Just prior to testing, the smoking articles are placed in glass beakers
to assure free air access.
[0038] SE testing takes place within an enclosure or test box. A single port smoking machine
or an electric lighter is used to ignite the smoking articles for the test. During
testing, an apparatus or "angle holder" holds the smoking articles to be tested by
holding an end at angles of 0° (horizontal), 45°, and/or 90° (vertical). Preferably,
twenty (20) smoking articles are tested at each of the 0°, 45°, and 90° positions.
If more than one apparatus is used, the apparatuses are preferably positioned such
that the smoking articles face away from each other to avoid cross interference. If
a smoking article goes out before the front line of the smoldering coal reaches the
tipping paper, the outcome is scored as "self-extinguishment"; on the other hand,
if the smoking article continues smoldering until the front line of the smoldering
coal reaches the tipping paper, then the outcome is scored as "non-extinguishment".
Thus, for example, an SE value of 95% indicates that 95% of the smoking articles tested
exhibited self-extinguishment under free burn conditions; while an SE value of 20%
indicates that only 20% of the smoking articles tested exhibited self-extinguishment
under such free burn conditions.
[0039] The SE value for a smoking article should be no greater than about 80% (at horizontal
orientation) and preferably no greater than about 50% and even more preferably no
greater than about 25% as described in
US Patent Application Publication No. 2013/0306082 published Nov. 21, 2013, the entire content of which is incorporated herein by reference thereto. It is desirable
to achieve IP performance that meets and exceeds governmental requirements. Moreover,
as also previously noted, that desired IP performance often adversely impacts the
SE performance of the smoking article. Stated differently, while the IP performance
may meet or exceed the governmental requirements, that IP performance is typically
associated with a smoking article that will self-extinguish when hand held by a smoker--an
SE of 100%. Since smokers ordinarily prefer not to need to relight a smoking article,
improvement of SE performance while maintaining IP performance constitutes a highly
desirable feature for improved wrappers.
[0040] To improve SE performance, certain example band configurations disclosed herein are
useful in constructing smoking articles having both improved SE performance and desired
IP performance. For example, a band 126 configuration such as shown in FIG. 6 is capable
of better sustaining smoldering during free burns, yet when placed adjacent a substrate,
does not sustain smoldering. In addition, about 10% IP can be obtained for paper having
diffusion ranging from about 0 to about 0.2 cm/sec, while maintaining about 18% SE,
by controlling the print area and volume of fibrous crystalline cellulosic slurry
printed on the base web 140.
[0041] According to an example embodiment, as shown in FIG. 6, banded wrapper paper 123
can include a base web 140 which includes a plurality of bands of fibrous crystalline
cellulosic material 126 on one or both sides thereof. In an example embodiment, the
bands of fibrous crystalline cellulosic material 126 can be arranged on the base web
140 such that a smoking article 120 (see e.g., FIG. 1) including a piece of the banded
wrapper paper 123 includes at least two bands of fibrous crystalline cellulosic material
126, wherein each band of fibrous crystalline cellulosic material has a first zone
202, a second zone 203, and optionally a third zone 204 of fibrous crystalline cellulosic
material wherein the amount of the fibrous cellulosic crystalline cellulosic material
within each zone can be selected to control the IP performance and/or SE performance
of a smoking article including the wrapper paper. In an example embodiment, the first
zone 202 and the third zone 204 include about the same amount of fibrous crystalline
cellulosic material on the base web 140, while the second zone 203 has about 20% to
about 80% (e.g., about 25% to about 75%, about 30% to about 70%, about 35% to about
65%, about 40% to about 60%, or about 45% to about 55%) less fibrous crystalline cellulosic
material on the base web 140 than the first or third zones 202, 204.
[0042] In an example embodiment, the fibrous crystalline cellulosic material of each zone
is applied as a plurality of dots of fibrous crystalline cellulosic slurry arranged
in a pattern, generally within the zone, to produce a banded region of fibrous crystalline
cellulosic material on the base web 140. Moreover, each dot of fibrous crystalline
cellulosic slurry printed in the second zone 203 has smaller dimensions than each
dot of fibrous crystalline cellulosic slurry printed in the first zone 202 and the
third zone 204. FIG. 7 shows an example embodiment of a patterned portion of a gravure
cylinder (roller) 610 that may be used to print banded regions of fibrous crystalline
cellulosic slurry to form banded regions of fibrous crystalline cellulosic material
126 which have a first zone 202, a second zone 203, and a third zone 204 of fibrous
crystalline cellulosic material. In an example embodiment, the first, second, and
third zones 202, 203, 204 of each banded region 126 are directly adjacent to one another
such that they are not separated by a length of base web 140 that is free of added
fibrous crystalline cellulosic material. As shown in FIG. 7, the gravure roller 610
includes a plurality of cells 700 etched thereon in a pattern corresponding to the
aforementioned zones 202, 203, 204 wherein the cells 700 have a generally hexagonal
shape. In an example embodiment, the gravure cylinder 610 includes first and third
zones 712 and a second zone 710 therebetween wherein walls 720 between adjacent cells
722 in the first and third zones 712 have a narrower width than walls 724 between
adjacent cells 726 of the second zone 710. Because the walls 724 between adjacent
cells 726 of the gravure cylinder 610 used to form the dots of printed slurry in the
second zone 203 are thicker, less fibrous crystalline cellulosic slurry is applied
by the gravure roller 610 and the dots of printed slurry tend to stay separated once
printed on the base web 140. In contrast, dots of printed slurry in the first zone
202 and third zone 204 are formed by a gravure roller 610 including cells 722 having
thinner walls 720 between adjacent cells 726, such that a greater amount of fibrous
crystalline cellulosic slurry is applied and the dots of printed slurry tend to run
together when printed on the base web 140. In an example embodiment, the walls 724
of the cells 726 may be configured such that the dots of printed slurry run together
when printed on the base web 140. In an example embodiment, the walls 720 between
adjacent cells 726 of the first and/or third zones 202, 204 may be configured such
that the dots printed thereby tend to stay separated once printed on the base web
140.
[0043] In example embodiments, the first zone 202 and the third zone 204 can have a diffusivity
ranging from about 0 to about 0.1 cm/sec (e.g. about 0.01 to about 0.09 cm/sec, about
0.02 to about 0.08 cm/sec, about 0.03 to about 0.07 cm/sec or about 0.04 to about
0.06 cm/sec), and the second zone 203 can have a diffusivity ranging from about 0.1
to about 0.4 cm/sec (e.g. about 0.15 to about 0.35 cm/sec or about 0.2 to about 0.3
cm/sec).
[0044] When the word "about" is used in this specification in connection with a numerical
value, it is intended that the associated numerical value include a tolerance of +/-10%
around the stated numerical value. Moreover, when reference is made to percentages
in this specification, it is intended that those percentages are based on weight,
i.e., weight percentages.
[0045] The terms and phrases used herein are not to be interpreted with mathematical or
geometric precision, rather geometric terminology is to be interpreted as meaning
approximating or similar to the geometric terms and concepts. For example, rounded
or filleted corners are intended to be included in geometric shapes such as a rectangular,
hexagonal, and the like. Terms such as "generally" and "substantially" are intended
to encompass both precise meanings of the associated terms and concepts as well as
to provide reasonable latitude which is consistent with form, function, and/or meaning.
[0046] It will now be apparent to those skilled in the art that this specification describes
a new, useful, and nonobvious smoking article, wrapper therefor, and process for making
the wrapper and smoking article. It will also be apparent to those skilled in the
art that numerous modifications, variations, substitutes, and equivalents exist for
various aspects of the smoking article, wrapper and process that have been described
in the detailed description above. Accordingly, it is expressly intended that all
such modifications, variations, substitutions, and equivalents that fall within the
spirit and scope of the invention, as defined by the appended claims, be embraced
thereby.
[0047] By way of example, embodiments of the invention comprise the following features:
- 1. A smoking article, comprising:
a tobacco rod comprising a column of filler and a wrapper surrounding the column of
filler, the tobacco rod having a circumferential direction, a longitudinal direction,
a lit end, and a mouth end;
the wrapper further including a base web having generally parallel first and second
side edges extending in the longitudinal direction and two ends extending in the circumferential
direction wherein the base web is disposed around the column of filler such that the
first and second side edges of the base web overlap and form a seam, the base web
having at least one circumferentially extending banded region of fibrous crystalline
cellulosic material thereon, the fibrous crystalline cellulosic material having been
gravure printed on the base web as a fibrous crystalline cellulosic slurry comprising
water, crystalline cellulose, and chalk wherein the fibrous crystalline cellulosic
slurry has a solids content of about 10% or less by weight of the fibrous crystalline
cellulosic slurry.
- 2. The smoking article of claim 1, wherein (a) the tobacco rod has a filter attached
to the mouth end; (b) the chalk is calcium carbonate; (c) the base web includes at
least two longitudinally spaced circumferentially extending banded region of fibrous
crystalline cellulosic material thereon; (d) the at least one circumferentially extending
banded region of fibrous crystalline cellulosic material is printed as a single layer;
(e) the at least one circumferentially extending banded region of fibrous crystalline
cellulosic material is printed in at least two layers; (f) the base web has a permeability
of greater than about 20 CORESTA and less than about 100 CORESTA in regions outside
of the at least one circumferentially extending banded region of fibrous crystalline
cellulosic material and a CORESTA of 12 or less in regions within the at least one
circumferentially extending banded region of fibrous crystalline cellulosic material;
(g) the at least one circumferentially extending banded region of fibrous crystalline
cellulosic material includes microcrystalline cellulose; (h) the at least one circumferentially
extending banded region of fibrous crystalline cellulosic material is free of any
binders, modified cellulose, and bacterial cellulose; (i) the fibrous crystalline
cellulosic material consists essentially of about 95% microcrystalline cellulose and
about 5% chalk; (j) the fibrous crystalline cellulosic material includes microcrystalline
cellulose, a binder, and chalk, wherein the binder is included in an amount of about
9% or less by weight of the of the microcrystalline cellulose; (k) the fibrous crystalline
cellulosic material includes microcrystalline cellulose wherein at least 90% of the
fibers of the microcrystalline cellulose have a size of about 200 microns or less;
(1) the fibrous crystalline cellulosic material includes microcrystalline cellulose
wherein at least 90% of the fibers of the microcrystalline cellulose have a size of
about 200 microns or less; (m) the at least one banded region of fibrous crystalline
cellulosic material includes up to about 2.5 gsm of added fibrous crystalline cellulosic
material; (n) the Ignition Propensity of the smoking article is no greater than 25%
and the Self-Extinguishment of the smoking article is no greater than 50%; or (o)
the at least one banded region of fibrous crystalline cellulosic material includes
a first zone, a second zone, and a third zone wherein the first and third zones include
about the same amount of fibrous crystalline cellulosic material and the second zone
includes less fibrous crystalline cellulosic material than the first or third zones.
- 3. The smoking article of claim 2, wherein the base web is free of added fibrous crystalline
cellulosic material in regions outside of the at least two longitudinally spaced circumferentially
extending banded region of fibrous crystalline cellulosic material.
- 4. A wrapper for smoking articles, comprising:
a base web having generally parallel first and second side edges extending in a longitudinal
direction and two ends extending in a transverse direction and a plurality of longitudinally
spaced banded regions of fibrous crystalline cellulosic material thereon, the fibrous
crystalline cellulosic material having been gravure printed on the base web as a fibrous
crystalline cellulosic slurry comprising water, crystalline cellulose, and chalk wherein
the fibrous crystalline cellulosic slurry has a solids content of about 10% or less
by weight of the fibrous crystalline cellulosic slurry.
- 5. The wrapper of claim 4, wherein: (a) the chalk is calcium carbonate; (b) the base
web is free of added fibrous crystalline cellulosic material in regions outside of
the plurality longitudinally spaced banded regions of fibrous crystalline cellulosic
material; (c) the plurality longitudinally spaced banded regions of fibrous crystalline
cellulosic material are each printed as a single layer; (d) the plurality longitudinally
spaced banded regions of fibrous crystalline cellulosic material are each printed
in at least two layers; (e) the base web has a permeability of greater than about
20 CORESTA and less than about 100 CORESTA in regions outside of the plurality longitudinally
spaced banded regions of fibrous crystalline cellulosic material and a CORESTA of
12 or less in regions within the plurality longitudinally spaced banded regions of
fibrous crystalline cellulosic material; (f) the plurality longitudinally spaced banded
regions of fibrous crystalline cellulosic material includes microcrystalline cellulose;
(g) the plurality longitudinally spaced banded regions of fibrous crystalline cellulosic
material are free of any binders, modified cellulose, and bacterial cellulose; (h)
the fibrous crystalline cellulosic material consists essentially of about 95% microcrystalline
cellulose and about 5% chalk; (i) the fibrous crystalline cellulosic material includes
microcrystalline cellulose, a binder, and chalk, wherein the binder is included in
an amount of about 9% or less by weight of the of the microcrystalline cellulose;
(j) the fibrous crystalline cellulosic material includes microcrystalline cellulose
wherein at least 90% of the fibers of the microcrystalline cellulose have a size of
about 200 microns or less; (k) the plurality longitudinally spaced banded regions
of fibrous crystalline cellulosic material each include up to about 2.5 gsm of added
fibrous crystalline cellulosic material; or (1) the plurality longitudinally spaced
banded regions of fibrous crystalline cellulosic material each include a first zone,
a second zone, and a third zone wherein the first and third zones include about the
same amount of fibrous crystalline cellulosic material and the second zone includes
less fibrous crystalline cellulosic material than the first or third zones.
- 6. A method of making banded wrapper paper for smoking articles, the method comprising:
advancing a base web to a first printing station;
printing a first layer of a fibrous crystalline cellulosic slurry on the base web,
the fibrous crystalline cellulosic slurry comprising water, crystalline cellulose,
and chalk wherein the fibrous crystalline cellulosic slurry has a solids content of
about 10% or less by weight of the fibrous crystalline cellulosic slurry, said printing
comprising applying the fibrous crystalline cellulosic slurry to a patterned gravure
roller, and contacting the advancing base web with the patterned gravure roller to
apply bands of the fibrous crystalline cellulosic slurry on the base web; and
forming banded regions of fibrous crystalline cellulosic material on the base web
by drying the bands of the fibrous crystalline cellulosic slurry.
- 7. The method of making the banded wrapper paper of claim 6, wherein: (a) the fibrous
crystalline cellulosic slurry is not heated when applied to the gravure roller; (b)
the drying comprises passing the base web over at least one steam can; (c) only the
first layer of fibrous crystalline cellulosic slurry is printed on the base web; (d)
the amount of fibrous crystalline cellulosic slurry applied to the base web is sufficient
to form banded regions of fibrous crystalline cellulosic material having a weight
of about 2.5 gsm; or (e) permeability of the banded wrapper paper in regions outside
of the banded regions of fibrous crystalline cellulosic material is about 20 CORESTA
to about 100 CORESTA, and permeability of the banded wrapper paper within the banded
regions of fibrous crystalline cellulosic material is about 12 CORESTA or less.
- 8. The method of making the banded wrapper paper of claim 6, including a step of printing
a second layer of the fibrous crystalline cellulosic slurry on top of the first layer.
- 9. The method of making the banded wrapper paper of claim 8, wherein (a) the second
layer is printed with a coat weight that is at least 1% greater than a coat weight
of the first printed layer; or (b) including drying the base web between printing
of the first and second layers.
- 10. The method of making the banded wrapper paper of claim 6, wherein the fibrous
crystalline cellulosic slurry comprises water, crystalline cellulose, and chalk.
- 11. The method of making the banded wrapper paper of claim 10, wherein: (a) the fibrous
crystalline cellulosic slurry includes at least 90% by weight water, up to 10% microcrystalline
cellulose and up to 1% chalk; (b) the fibrous crystalline cellulosic slurry consists
essentially of water, microcrystalline cellulose, and chalk; or (c) the fibrous crystalline
cellulosic slurry includes a binder.
- 12. The method of making the banded wrapper paper of claim 6, wherein the fibrous
crystalline cellulosic slurry is continuously agitated before applied to the gravure
roller.
- 13. The method of making the banded wrapper paper of claim 6, wherein the gravure
roller is configured to apply a quantity of the fibrous crystalline cellulosic slurry
in a single pass sufficient to provide self-extinguishment of a smoking article incorporating
the banded wrapper paper.
- 14. The method of making the banded wrapper paper of claim 6, wherein the fibrous
crystalline cellulosic slurry includes up to 9.5 weight % cellulosic fibrous crystalline
material and up to 5.5 weight % chalk.
- 15. The method of making the banded wrapper paper of claim 6, wherein: (a) the fibrous
crystalline cellulosic slurry includes microcrystalline cellulose with a fiber size
of less than 200 microns; (b) the gravure roller has hexagonal cells separated by
cell walls having a thickness of 12 to 20 microns; or (c) printing the plurality longitudinally
spaced banded regions of fibrous crystalline cellulosic slurry includes applying the
fibrous crystalline cellulosic slurry of each banded region in a first zone, a second
zone, and a third zone wherein the first and third zones include about the same amount
of fibrous crystalline cellulosic slurry and the second zone includes less fibrous
crystalline cellulosic slurry than the first or third zones.
1. A smoking article, comprising:
a tobacco rod including,
a column of filler, and
a wrapper surrounding the column of filler, the tobacco rod having a circumferential
direction, a longitudinal direction, a lit end, and a mouth end; the wrapper including,
a base web having generally parallel first and second side edges extending in the
longitudinal direction and two ends extending in the circumferential direction, the
base web being around the column of filler such that the first and second side edges
of the base web overlap and form a seam, the base web having at least one circumferentially
extending banded region of a fibrous crystalline cellulosic material thereon,
the fibrous crystalline cellulosic material having been gravure printed on the base
web as a fibrous crystalline cellulosic slurry including water, crystalline cellulose,
and chalk, the fibrous crystalline cellulosic slurry having a solids content of about
10% or less by weight of the fibrous crystalline cellulosic slurry, the solids including
the crystalline cellulose and chalk in a ratio of 94.5 to 5.5 to a ratio of 95 to
5, and the at least one circumferentially extending banded region of fibrous crystalline
cellulosic material being free of modified cellulose or bacterial cellulose.
2. The smoking article of claim 1, wherein the tobacco rod has a filter at the mouth
end.
3. The smoking article of claim 1, wherein the chalk is calcium carbonate.
4. The smoking article of claim 1, wherein the base web includes at least two longitudinally
spaced circumferentially extending banded regions of fibrous crystalline cellulosic
material thereon.
5. The smoking article of claim 4, wherein the base web is free of added fibrous crystalline
cellulosic material in regions outside of the at least two longitudinally spaced circumferentially
extending banded regions of fibrous crystalline cellulosic material.
6. The smoking article of claim 1, wherein the at least one circumferentially extending
banded region of fibrous crystalline cellulosic material is printed as a single layer.
7. The smoking article of claim 1, wherein the at least one circumferentially extending
banded region of fibrous crystalline cellulosic material is printed in at least two
layers.
8. The smoking article of claim 1, wherein the base web has a permeability of greater
than about 20 CORESTA and less than about 100 CORESTA in regions outside of the at
least one circumferentially extending banded region of fibrous crystalline cellulosic
material and a CORESTA of 12 or less in regions within the at least one circumferentially
extending banded region of fibrous crystalline cellulosic material.
9. The smoking article of claim 1, wherein the at least one circumferentially extending
banded region of fibrous crystalline cellulosic material includes microcrystalline
cellulose.
10. The smoking article of claim 1, wherein the at least one circumferentially extending
banded region of fibrous crystalline cellulosic material is free of any binders.
11. The smoking article of claim 1, wherein the fibrous crystalline cellulosic material
consists essentially of about 95% microcrystalline cellulose and about 5% chalk.
12. The smoking article of claim 1, wherein the fibrous crystalline cellulosic material
includes microcrystalline cellulose, a binder, and chalk, wherein the binder is included
in an amount of about 9% or less by weight of the of the microcrystalline cellulose.
13. The smoking article of claim 1, wherein the fibrous crystalline cellulosic material
includes microcrystalline cellulose wherein at least 90% of the fibers of the microcrystalline
cellulose have a size of about 200 microns or less.
14. The smoking article of claim 1, wherein the at least one banded region of fibrous
crystalline cellulosic material includes up to about 2.5 gsm of added fibrous crystalline
cellulosic material.
15. The smoking article of claim 1, wherein the Ignition Propensity of the smoking article
is no greater than 25% and the Self-Extinguishment of the smoking article is no greater
than 50%.
16. The smoking article of claim 1, wherein
the at least one banded region of fibrous crystalline cellulosic material includes
a first zone, a second zone, and a third zone, and
the first and third zones include about the same amount of fibrous crystalline cellulosic
material and the second zone includes less fibrous crystalline cellulosic material
than the first or third zones.