[0001] US-A-2004/0099280 discloses a wrapper for a cigarette having two zones of three superimposed layers
of add-on material separated by a gap to form a banded region. The layer bottom layer
the zones Is wider than the middle layer which Is wider than the top layer.
SUMMARY
[0002] According to the present invention there is provided a wrapper of a smoking article,
comprising a base web and at least one transverse banded region comprising first,
second and third zones, said first and third zones comprising add-on material, which
reduces permeability of said wrapper, said first and third zones being separated by
said second zone, said wrapper having greater permeability along said second zone
than along said first and third zones, said second zone having a width less than the
width of either of the said first and third zones, characterised in that the add-on
material is uniform across each of the first and third zones, said first and third
(zones each have a width of 2 mm to 5 mm such that if either of said first or third
zone were applied separately to wrappers of smoking articles the smoking articles
would exhibit total burn through and substantially no occurrences of self-extinguishment
under free burn conditions the sum of said widths of said first and third zones Is
such that if the first and third zones were applied to wrappers of smoking articles
as a single continuous band, the smoking articles would exhibit substantially no occurrences
of total burn through and self-extinguishment under free burn conditions, so that
lit smoking articles comprising said first, second and third zones exhibit reduced
occurrences of self-extinguishment under free burn conditions, as compared to smoking
articles comprising wrappers whereon the first and third zones are applied as a single
continuous band, while maintaining substantially no occurrences of total burn through.
[0003] In some embodiments, the at least one transverse banded region is free of fillers.
[0004] The invention also provides a method of making a banded wrapper comprising supplying
a base web and forming at least one transverse banded region comprising first, second
and third zones on the base web, wherein the first and third zones are outward of
the second zone, wherein the second zone has a greater permeability compared to the
first and third zones, wherein the width of the second zone is less than those of
the first and third zones, characterised in that the first and third zones are formed
so that the add-on material is uniform across each of the first and third zones and
in that the first and third zones are formed so that each of the first and third zones
has a width of 2 mm to 5 mm such that if either of said first or third zone were applied
separately to wrappers of smoking articles the smoking articles would exhibit total
burn through and substantially no occurrences of self-extinguishment under free burn
conditions. Preferably, at least the first and third zones are formed from an add-on
material free of fillers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005]
FIGs. 1-3 are illustrations of smoking articles comprising the slit banded paper as
described herein.
FIGs. 4-5 illustrate alternate embodiments of smoking articles comprising the split
banded paper as described herein.
FIG. 6 is a schematic view of a multiple stage printing apparatus.
DETAILED DESCRIPTION
[0006] Preferably, a smoking article extinguishes when placed onto a substrate, and the
tendency to do so is referenced herein as a smoking article having "low ignition propensity".
Ideally, a low propensity smoking article will continue to burn when freely suspended
such as within the holder of an ashtray or when being held in the hand without puffing
("free burn"). Many prior cigarette designs that achieve low ignition propensity requirements
exhibit high rates of self-extinguishment under free burn conditions.
[0007] The phrase "total burn through" as used herein, refers to testing by American Society
of Testing and Materials (ASTM) Standard E2187-04, "Standard Test Method for Measuring
the Ignition Strength of Cigarettes", which provides a measure of the capability of
a lit banded-papered cigarette, positioned on a combustible substrate, to continue
burning without puffing. Thus, "total burn through" refers to the situation in which
the coal proceeds entirely through a banded region on a cigarette wrapper and does
not cause extinguishment of the lit cigarette. Further, the phrases "self-extinguish
under free burn conditions" or "self-extinguishment under free burn conditions" as
used herein, refer to the extinguishment of a lit cigarette without puffing, when
such cigarette is under free burn conditions.
[0008] The banded regions described herein exhibit both low ignition propensity and reduced
rates of self-extinguishment under free burn conditions. The banded regions are preferably
formed by printing, specifically gravure printing, as described in detail below. As
an alternative to printing, the banded regions may comprise a slurry of highly refined
fibrous cellulose (
e.g., fibers, fibrils, microfibrils, or combinations thereof) or other add-on material
applied using various spray or coating techniques, including application techniques
that utilize a moving orifice applicator at the forming section of a paper-making
machine as described in commonly owned
US 5 997 691 and
US 6 596 125.
[0009] The second zone may include perforations which preferably are filled with an occluding
material which melts or is evaporated when the burning coal approaches the banded
region to thereby provide the second zone with increased permeability.
[0010] The first and third zones each have a width such that if either of said first or
third zone were applied separately to wrappers of smoking articles, the smoking articles
would exhibit statistically significant occurrences of total burn through and statistically
few or no occurrences of self-extinguishment under free burn conditions (
e.g., after testing a batch of 20 to 50 cigarettes). The sum of the widths of the first
and third zones is such that if the zones were applied to wrappers of smoking articles
as a single continuous band (without a slit or other discontinuity), the smoking articles
would exhibit statistically few or no occurrences of total burn through and statistically
significant occurrences of self-extinguishment under free burn conditions. The first
and third zones are separated by the second zone. The second zone comprises less add-on
material than the first and third zones or no add-on material. The wrapper has greater
permeability along the second zone than along the first and third zones. The second
zone has a width less than either width of the first and third zones (which can have
equal or unequal widths), so that lit smoking articles comprising the first, second
and third zones exhibit statistically reduced occurrences of self-extinguishment under
free burn conditions, as compared to smoking articles comprising wrappers whereon
the first and third zones are applied as a single continuous band, while maintaining
statistically few or no occurrences of total burn through. Preferably, the first and
third zones are of uniform add-on material across the first and third zones. Optionally,
the second zone may have a width essentially equal to the first and third zones.
[0011] Total weight of add-on material for the banded region preferably lies in the range
of 0.5 grams per square meter (g/m
2) to 15 g/m
2, more preferably in the range of from 0.5 g/m
2 to 3 g/m
2, even more preferably In the range of from 0.5 g/m
2 to 1.5 g/m
2, approximately. Conventional cigarette paper is permeable, with the permeability
commonly designated in CORESTA, which measures paper permeability in terms of volumetric
flow rate (cm
3/sec) per unit area (cm
2) per unit pressure drop (cm of water). Permeability of the cigarette paper normally
exceeds 20 CORESTA and preferably, the cigarette paper has a permeability of about
33 to about 60 CORESTA and a basis weight of about 22 g/m
2 30 g/m
2. However, permeability through the banded regions and the underlying cigarette paper
preferably lies in the range of 0 to 15 CORESTA. The reduction in permeability preferably
restricts air flow needed to support combustion of the cigarette coal in the vicinity
of the banded region.
[0012] The first and third zones preferably have a greater basis weight In grams per square
meter than the intermediate second zone; for example, the basis weight in grams per
square meter of the first and third zones may be at least twice the basis weight in
grams per square meter of the second zone. The second zone may comprise a gap. As
used herein, the term "gap" refers to a discrete area of a banded region, between
the first and third zones, lacking any permeability reducing add-on material (
i.e., containing no layers of permeability reducing add-on material). In order to aid
combustion in the second zone, the wrapper may comprise iron oxide at the location
of the second zone. The second zone preferably has a greater permeability than the
first and third zones.
[0013] The at least one transverse banded region preferably comprises a first printed layer
contacting the base web and a second printed layer, preferably having an equal or
greater basis weight in grams per square meter than the first printed layer, on the
first printed layer. However, the second and/or subsequent layers may be less in basis
weight than the first layer. For example, the basis weight in grams per square meter
of the second printed layer may be at least twice the basis weight in grams per square
meter of the first printed layer. In an embodiment, the second zone may comprise a
single printed layer and the first and third zones may each comprise at least two
printed layers (more preferably three or more layers). Alternatively, the first and
third zones may each comprise at least three or four printed layers, and the second
zone may comprise only one or two or no printed layers.
[0014] Non-banded areas of the base web preferably do not comprise permeability reducing
add-on material. As described below with reference to FIG. 2, the transverse banded
region may comprise greater than three zones. For example, the transverse banded region
may comprise, for example, five zones, with the second and fourth zones separating
the first, third and fifth zones and the wrapper having greater permeability along
the second and fourth zones than along the first, third and fifth zones.
[0015] The at least one transverse banded region can be free of fillers and optionally at
least one of the zones is formed at least in part from an add-on material which includes
a filler. The add-on material is preferably uniform across the first and third zones.
The first and third zones are outward of the second zone, and the overall wrapper
structure at the second zone has a greater permeability compared to the overall wrapper
structure at the first and third zones.
[0016] The wrappers of the invention are preferably supplied on bobbins and it is preferred
that the wrapper on the bobbin comprises evenly spaced apart transverse banded regions
or a repeating series of transverse banded regions.
[0017] Optionally at least one of the zones is formed at least in part from an add-on material
which includes a filler. The add-on material is preferably uniform across the first
and third zones.
[0018] FIGs. 1-3 illustrate smoking articles comprising slit banded paper as described herein.
Specifically, FIG. 1 illustrates a smoking article having two banded regions 10 on
a base web 100, each comprising first and third zones of add-on material 11, 13 separated
by a second zone 12, which may be in the form of a gap or may be in the form of a
zone of reduced add-on material. The first and third zones of add-on material 11,
13 may each be, for example, about 2 mm to 5 mm, preferably about 2 mm to 3 mm, wide,
and the second zone 12 may be, for example, about 1 mm to 2 mm wide. More specifically,
the first and third zones of add-on material 11, 13 may each be, for example, about
3 mm wide, and the second zone 12 may be, for example, about 1.5 mm or 2 mm wide.
The first and third zones of add-on material 11, 13 preferably comprise multiple layers
of add-on material, such as, for example, two, three or four layers of add-on material.
The add-on material is preferably uniform across the first and third zones 11, 13.
[0019] FIG. 2 illustrates a smoking article having two banded regions 20 on a base web 100,
each comprising first, third and fifth zones of add-on material 21, 23, 25 separated
by second and fourth zones 22, 24, which may be in the form of gaps or In the form
of reduced levels of add-on material. The first, third and fifth zones of add-on material
21, 23, 25 may each be, for example, about 2 mm to 3 mm wide, and the second and fourth
zones 22, 24 may each be, for example, about 1 mm to 2 mm wide. More preferably, the
first, third and fifth zones of add-on material 21, 23, 25 may each be, for example,
about 2 mm wide, and the second and fourth zones 22, 24 may each be, for example,
about 1 mm wide or less. The first, third and fifth zones of add-on material 21, 23,
25 preferably comprise multiple layers of add-on material, such as, for example, two,
three or four layers of add-on material. The add-on material is preferably uniform
across the first, third and fifth zones 21, 23, 25.
[0020] FIG. 3 illustrates a smoking article having two banded regions 30 on a base web 100,
each comprising first and third zones of add-on material 31, 33 separated by a second
zone of less add-on material 32. The first and third zones of add-on material 31,
33 may each be, for example, about 2 mm to 3 mm wide, and the second zone of less
add-on material 32 may be, for example, about 1 mm to 2 mm wide. More preferably,
the first and third zones of add-on material 31, 33 may each be, for example, about
3 mm wide, and the second zone of less add-on material 32 may be, for example, about
2 mm wide or less. The first and third zones of add-on material 31, 33 preferably
comprise multiple layers of add-on material, such as, for example, two, three or four
layers of add-on material, while the second zone of less add-on material 32 may comprise,
for example, one or two layers of add-on material. The add-on material is preferably
uniform across the first and third zones 31, 33. Although second zones 32 are operative
at a 1 mm width, the embodiment performs better at a 1.2 mm width or greater.
[0021] Referring to FIGs. 1-3, slit banded paper facilitates use of wrappers of lower permeability
for a given level of CO than prior designs of banded paper. For example, it was found
in some circumstances that a tobacco rod comprising paper having a permeability of
33 CORESTA and a CO (FTC) delivery of 11 mg would produce 15mg of CO (FTC) if previous
versions of bands were applied without further change. In order to counteract his
Increase, the permeability of the wrapper would have to be raised to about 46 CORESTA.
Such changes create a multitude of consequence in cigarette design, such as, for example,
impacting puff count, possibly lessening machinability of the paper, and the like.
In contrast, the slit banded paper having a permeability of 33 CORESTA provided 12mg
CO (FTC). Thus, the slit banded banded technology described herein facilitates application
of bands with a lesser impact on CO levels (FTC).
[0022] Referring to FIGs. 4 and 5, further embodiments may include banded regions wherein
the zones extend longitudinally instead of circumferentially. More specifically, FIG.
4 corresponds to banded region configuration of FIG. 2 with the zones extend longitudinally
instead of circumferentially, and FIG. 5 corresponds to banded region configuration
of FIG. 3 with the zones extend longitudinally instead of circumferentially.
[0023] In a preferred embodiment, the first layer of each banded region is preferably formed
using an aqueous occlusive composition, which extends completely across the banded
region. The successive layer (or layers) of each banded region may be formed by using
the same aqueous film forming composition or different aqueous compositions. For example,
multiple layers may all comprise layers containing exclusively starch or multiple
layers may comprise one or more layers containing exclusively starch and one or more
layers containing calcium carbonate (in any order), During gravure printing, the occlusive
composition is preferably heated to a temperature where its viscosity lies within
the range of viscosities suitable for gravure printing. When the heated occlusive
composition is applied, the occlusive composition is cooled or quenched and may be
gelatinized. Thus, a portion of the free water in the occlusive composition becomes
bound and unavailable to soak or migrate into underlying fibers of the base web. That
binding of free water inhibits formation of waviness, cockling, and/or wrinkling in
the base web. Successive layers of the banded regions preferably have increased thickness
relative to the first layer. The banded regions provide a reduction in permeability
to the underlying base web, which preferably restricts air flow needed to support
combustion of the cigarette coal in the vicinity of the banded region. Further details
of progressive multi-pass printing can be found in commonly owned
U.S. Provisional Application No. 60/707,964 entitled PROGRESSIVE MULTI-PASS PRINT BANDED PAPER filed August 15, 2005.
[0024] The occlusive composition used in the occlusive composition may be selected from
the group consisting of starch, alginate, carrageenan, guar gum, pectin, and mixtures
thereof. Preferably, the occlusive composition comprises starch, more preferably oxidized
starch, such as, for example, tapioca starch, more specifically oxidized tapioca starch.
In embodiments, the occlusive composition preferably does not contain fillers, such
as, for example, calcium carbonate, which would increase the burn rate through the
banded region. In a preferred embodiment, the occlusive composition used for printing
comprises water and about 20% to about 50%, by weight, of the occlusive composition.
At higher concentrations of the occlusive composition in the composition, the composition
may experience gelatinization when its temperature is rapidly reduced. Thus, the binding
of free water into the printed banded region may occur,
[0025] At room temperature (about 23°C), the high-solids-content occlusive composition has
a viscosity exceeding about 2mPa·s (200 centipoise (cP)) and is unsuitable for gravure
printing; however, at a temperature in the range of about 40°C to about 90°C, the
viscosity of the occlusive composition is decreased sufficiently for use as a gravure
printing composition. For gravure printing, the upper limit of suitable viscosity
is about 2mPa·s (200 cP). Most preferably, the occlusive composition has a viscosity
of about 1mPa·s (100 cP) at a temperature in the range of 40°C to 90°C so that the
composition can be quenched on contact with the paper after gravure printing at that
temperature. The viscosity of the composition at room temperature is also important.
The high viscosity at room temperature is needed so that the occlusive composition
gels at room temperature.
[0026] Preferably, the banded regions are applied to the wrapper using a successive gravure
printing process. Gravure printing operations are capable of precise registry of successive
printing operations. Accordingly, gravure printing can be used to effectively print
not only the first layer of the banded regions, but also the optional successive layers.
[0027] In a successive gravure printing process, preferably after the first layer is applied
to the base web it is allowed to dry thereon using suiting arrangements, prior to
being advanced to a second gravure printing station where a second layer is applied
to the first layer using conventional successive-pass gravure printing equipment.
Preferably, the second layer is coextensive with the first layer in both width and
length; however, the second layer may have a different basis weight in grams per square
meter than the first layer. The occlusive composition of the second layer gels on
the cooler first layer - and free water does not migrate or become absorbed by the
paper. Preferably, the second layer is allowed to dry using suitable arrangements
prior to being advanced to successive gravure printing station(s) where successive
layer(s) are applied. Preferably, the successive layer(s) are coextensive with the
previous layer(s) in both width and length (
i.e., the layers do not have a stepped appearance); however, the successive layer(s)
may have different basis weight in grams per square meter than the previous layer(s)
or may comprise different add-on compositions. Preferably, successive layer(s) are
preferably allowed to dry after the printing of each successive layer in accordance
with well-known gravure printing techniques and conventional gravure printing systems.
[0028] The gravure printing process can be used immediately following paper manufacture,
i.e., at a printing station at a location near the end of the paper making machine. Alternatively,
the gravure printing process can be used in connection with reels carrying the wrapper
onto which the banded regions are to be printed. For example, a reel of wrapper having
a selected permeability and a selected basis weight is mounted so that the wrapper
can be unspooled from the reel as a continuous base web.
[0029] The base web advances or passes through a first gravure printing station where the
first layer of each banded region is printed on the paper. The printing process may
be applied to the felt side or the wire side of the paper, or both. Next, the wrapper
passes through a second gravure printing station where a second layer of each banded
region is printed on the corresponding first layer. Additional layers are applied
in a similar manner as described. Finally, the wrapper with the printed banded regions
is wound up on a collection reel. The collection reel is then cut into bobbins. The
bobbins are then used during manufacture of the desired smoking article in conventional
tobacco rod making machines.
[0030] The apparatus at each of the gravure printing stations is essentially the same in
its material aspects. Accordingly, it will suffice to describe one of the gravure
printing stations in detail, it being understood that the other gravure printing stations
have common features, unless otherwise noted. A single pass technique can be used
to make the banded paper instead of a multi-pass technique.
[0031] At the first gravure printing station, the apparatus includes a gravure cylinder
or roller generally mounted for rotation around a horizontal axis. The generally cylindrical
surface of the roller is patterned (
i.e., with dots, lines, cells, etc.) in a suitable process to define a negative of the
first layer of banded regions. Conventional engraving (etching), chemical engraving,
electronic engraving, and photo etching can be used to pattern the surface of the
gravure cylinder. The circumference of the roller is determined such that it is an
integral multiple of the sum of the nominal distance between banded regions plus the
banded region width. Thus, for each revolution of the roller, that integral number
of first layers of the banded regions is printed on the wrapper.
[0032] With gravure printing, while each layer of add-on material may be applied uniformly,
each layer of add-on material need not be applied uniformly. For example, a layer
of add-on material may be applied such that discrete portions of the layer have differing
grams per square meter weights than other areas of the layer. This may be accomplished,
for example, by printing a discrete portion of the layer having a differing basis
weight than other areas of the layer in a separate printing stage using add-on material
having a differing basis weight. Alternatively, a layer of add-on material may be
applied such that discrete portions of the layer have differing depths than other
areas of the layer. This may be accomplished, for example, by patterning the gravure
cylinder or roller so as to provide a discrete portion of the layer having a differing
depth than other areas of the layer.
[0033] The multiple zones, for example, first, second and third zones, of the banded regions
described herein may be applied in a single printing stage or multiple printing stages.
When applied in multiple printing stages, each zone which contains add-on material
may be applied in a separate printing stage. For example, for a banded region containing
first, second and third zones, wherein only the first and third zones contain add-on
material, the first zone may be applied in a first printing stage and the third zone
may be applied in a second printing stage. Alternatively, when applied in a single
printing stage, the zones containing add-on material are applied using an appropriately
patterned gravure cylinder or roller. For example, for a banded region containing
first, second and third zones, wherein only the first and third zones contain add-on
material, the gravure cylinder or roller is patterned so as to apply add-on material
only in the first and third zones.
[0034] An impression cylinder is mounted for counter-rotation on an axis parallel to the
axis of the roller. In some applications, the impression cylinder includes a nonmetallic
resilient surface. The impression cylinder is positioned between the roller and a
backing roller, which is also mounted for rotation on an axis parallel to the axis
of the roller and which counter-rotates relative to the impression cylinder. One of
the functions provided by the backing roller is stiffening the central portions of
the Impression cylinder so that the uniform printing pressure is attained between
the roller and the impression cylinder. The gravure cylinder or roller and the impression
cylinder cooperate to define a nip through which the base web advances during the
printing process. That nip is sized to pinch the base web as it moves between the
gravure cylinder and the impression cylinder. The nip pressure on the base web ensures
the correct transfer of the composition from the cylinder to the paper.
[0035] A reservoir contains the occlusive composition discussed above for forming banded
regions on the wrapper. The reservoir communicates with a suitable pump which is capable
of handling the viscous occlusive composition. The occlusive composition may then
flow to a suitable heat exchanger where the temperature of the occlusive composition
is elevated so that it lies in the range of about 40° to about 90°C so that the viscosity
of the occlusive composition is adjusted to a level which is suitable for gravure
printing. As discussed above, viscosity for gravure printing usually needs to be less
than about 200 cP. Preferably, the temperature of the occlusive composition is selected
so that the viscosity is less than about 100 cP.
[0036] While a separate heat exchanger is disclosed, it may be desirable to provide thermal
conditioning of the occlusive composition in the reservoir itself. For example, heating
elements and stirring apparatus may be included in the reservoir to maintain the elevated
temperature for the occlusive composition. Placement of the thermal conditioning in
the reservoir has the advantage of making pump selection and operating requirements
simpler since the pump need not handle the occlusive composition at the higher viscosity
associated with lower temperatures because the occlusive composition would already
be heated and, therefore, at the lower viscosity. Whether thermal conditioning occurs
in the reservoir or in a separate heat exchanger, it is important that the thermal
conditioning step occur at a temperature selected to avoid scorching the occlusive
composition. Scorching can cause discoloration of the occlusive composition, and can
affect the occlusive characteristics of the composition. Thus, scorching is to be
avoided while the occlusive composition is subjected to thermal conditioning.
[0037] Regardless of where the thermal conditioning step occurs, the heated occlusive composition
is delivered to a suitable applicator that spreads the occlusive composition along
the length of the gravure cylinder. That spreading step may be effected by pouring
or spraying the occlusive composition onto the gravure cylinder, or simply by delivering
the liquid occlusive composition to a bath of occlusive composition that collects
at the bottom of the gravure cylinder, between the gravure cylinder and a collector.
The cylinder may be heated to prevent premature cooling of the composition.
[0038] Generally, the collector extends vertically around the gravure roller to a height
sufficient to collect the bath, but to a height well below the top of the gravure
cylinder. When the bath reaches the top of the collector, occlusive composition can
flow through a drain at the bottom of the apparatus back into the reservoir. Thus,
the occlusive composition circulates through the printing station and can be maintained
at suitable printing viscosity by the thermal conditioning apparatus discussed above.
[0039] As the gravure cylinder rotates through the applicator and/or the bath, the occlusive
composition adheres to the surface of the gravure cylinder, including in the impressions
provided therein to define the banded regions. Further rotation of the gravure cylinder
toward the nip moves the cylinder surface past a suitable doctor blade. The doctor
blade extends along the length of the gravure cylinder and is positioned so that is
wipes the surface of the gravure cylinder. In this way, those portions of the gravure
cylinder that define the nominal spacing between adjacent banded regions is essentially
wiped dean of the occlusive composition, while engraved portions of the gravure cylinder
that define the banded regions themselves advance toward the nip full of the occlusive
composition.
[0040] As the wrapper and the surface of the gravure cylinder move through the nip, the
occlusive composition is transferred to the surface of the wrapper. The linear speed
or velocity of the wrapper matches the tangential surface speed of both the gravure
cylinder and the impression cylinder as the wrapper passes through the nip. In that
way, slippage and/or smearing of the occlusive composition on the wrapper are avoided.
[0041] The thickness of the multilayer banded regions preferably is less than about 20%
of the thickness of the base web, and may be less than 5% of the thickness of the
base web. The thickness of the first layer of the banded region applied in the first
gravure printing station, preferably is less than 4% of the base web thickness, and
may be less than 1 % of the base web thickness. Thus, it is seen that the thickness
of the first layer is small in relation to the thickness of the underlying base web.
[0042] FIG. 6 is a schematic view of a multiple stage printing apparatus. With reference
to the above-description for multiple stage printing, FIG. 6 illustrates a reel 40,
first gravure printing station 42, second gravure printing station 44, third gravure
printing station 46, collection reel 48, rollers 50, impression cylinder 52, backing
roller 54, nips 56, reservoir 58, pump 60, heat exchanger 62, applicator 64, bath
66, collector 67, drain 68, doctor blade 70, adjustment cylinders 72, and idler roller
74. In FIG. 6, features of the first gravure printing station 42 contain reference
numerals with the suffix "a", corresponding features of the second gravure printing
station 44 contain the same reference numeral with the suffix "b", and corresponding
features of the third gravure printing station 46 contain the same reference numeral
with the suffix "c".
EXAMPLES
[0043] The following examples are intended to be non-limiting and merely illustrative. Cigarettes
with five different wrappers (
i.e., wrappers with five different banded region configurations), were tested for ignition
propensity ("IP") and self-extinguishment ("SE") at 0° (horizontal). The base web
of each of the wrappers had a permeability of 33 CORESTA and basis weight of 25 g/m
2, As used herein "IP" refers to total burn through of a cigarette. Accordingly, an
IP value of 0% indicates that 0% of the cigarettes tested exhibited total burn through,
an IP value of 2.5% indicates that 2.5% of the cigarettes tested exhibited total burn
through, and an IP value of 5% indicates that 5% of the cigarettes tested exhibited
total burn through. As used herein "SE" refers to self-extinguishment under free burn
conditions. Thus, for example, an SE value of 95% Indicates that 95% of the cigarettes
tested exhibited self-extinguishment under free burn conditions, while an SE value
of 20% indicates that 20% of the cigarettes tested exhibited self-extinguishment under
free burn conditions.
Table 1
Wrapper |
Banded Region Configuration* |
Total Banded Region Width |
IP Run 1 |
IP Run 2 |
IP Run 3 |
IP Avg. |
SE@0° |
A |
Control |
6 mm |
0% |
0% |
0% |
0% |
95% |
B |
3-1-3 |
7 mm |
0% |
2.5% |
0% |
0.8% |
60% |
C |
3-2-3 |
8 mm |
0% |
0% |
5% |
1.7% |
25% |
D |
2-1-2-1-2 |
8 mm |
2.5% |
2.5% |
2.5% |
2.5% |
20% |
* Numbers refer to zone widths in mm (see Tables 2-5, below) |
[0044] Referring to Table 1, wrapper A was a control, comprising a continuous, solid 6 mm
printed banded region, having an add-on rate of 5.5x. As used herein, an add-on rate
of 5.5x results in 8 g/m
2 to 9 g/m
2 of add-on material on a dry weight basis, and a basis weight of 26.5 g/m
2 for 6 mm banded regions with a 27 mm phase (
i.e., the spacing from the leading edge of a banded region to the leading edge of the
next banded region) applied to a base web with a basis weight of 25 g/m
2.
Table 2 - Details of Wrapper B
|
Zone 1 |
Zone 2 |
Zone 3 |
Width |
3 mm |
1 mm |
3 mm |
Layers of Add-on Material |
2 |
1 |
2 |
Add-on Rate Per Layer |
1.5x/4x |
1.5x/0 |
1.5x/4x |
Total Add-on Material |
5.5x |
1.5x |
5.5x |
Table 3 - Details of Wrapper C
|
Zone 1 |
Zone 2 |
Zone 3 |
Width |
3 mm |
2 mm |
3 mm |
Layers of Add-on Material |
2 |
1 |
2 |
Add-on Rate Per Layer |
1.5x/4x |
1.5x/0 |
1.5x/4x |
Total Add-on Material |
5.5x |
1.5x |
5.5x |
Table 4 - Details of Wrapper D
|
Zone 1 |
Zone 2 |
Zone 3 |
Zone 4 |
Zone 5 |
Width |
2 mm |
1 mm |
2 mm |
1 mm |
2 mm |
Layers of Add-on Material |
2 |
1 |
2 |
1 |
2 |
Add-on Rate Per Layer |
1.5x/4x |
1.5x/0 |
1.5x/4x |
1.5x/0 |
1.5x/4x |
Total Add-on Material |
5.5x |
1.5x |
5.5x |
1.5x |
5.5x |
[0045] As compared to control wrapper A, wrappers B-D exhibited the desired reduction in
SE while maintaining IP (
i.e., without significantly increasing IP). In particular, wrapper B exhibited an improvement
over control wrapper A, as evidenced by the decrease in SE average from 95%. to 60%.
The width of the second zone is preferably greater than 1 mm, preferably about 1.5
mm or about 2 mm. While good results were shown by wrapper C, which exhibited an SE
average of 45%, the best results were shown by wrapper D, which exhibited an SE average
of 20%.
[0046] It should be noted that wrapper D, having a banded region comprising first, second,
third, fourth and fifth zones and which showed the best results, had 1 mm second and
fourth zones of greater permeability. In contrast, wrapper B, having a banded region
comprising just first, second and third zones, with a 1 mm second zone of a greater
permeability, did not perform as well. Thus, wrappers having banded regions comprising
Just first, second and third zones preferably have wider zones of greater permeability
(
i.e., about 1.5 mm or about 2 mm) than the zones of greater permeability of wrappers having
banded regions comprising first, second, third, fourth and fifth zones.
[0047] The terms and phases 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. Terms such as "generally' 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.
[0048] While various embodiments have been described, it is to be understood that variations
and modifications may be resorted to as will be apparent to those skilled in the art.
For example, the embodiments are described as having slits preferably 1 mm to 2 mm
wide; other embodiments could be constructed with slits 1 mm to 3 mm wide. Such variations
and modifications are to be considered within the purview and scope of the claims
appended hereto.
1. A wrapper of a smoking article, comprising:
a base web (100); and
at least one transverse banded region (10)(20)(30) comprising first (11)(21)(31),
second (12)(22)(32) and third (13)(23)(33) zones,
said first (11)(21)(31) and third (13)(23)(33) zones comprising add-on material, which
reduces permeability of said wrapper, said first and third zones being separated by
said second zone (12)(22)(32),
said wrapper having greater permeability along said second zone (12)(22)(32) than
along said first (11)(21)(31) and third (13)(23)(33) zones, said second zone having
a width less than the width of either of the said first and third zones, the add-on
material is uniform across each of the first (11)(21)(31) and third (13)(23)(33) zones;
said first (11)(21)(31) and third (13)(23)(33) zones each have a width of 2 mm to
5 mm such that if either of said first or third zone were applied separately to wrappers
of smoking articles the smoking articles would exhibit statistically significant occurrences
of total burn through and statistically few or no occurrences of self-extinguishment
under free burn conditions;
the sum of said widths of said first (11)(21)(31) and third (13)(23)(33) zones is
such that if the first and third zones were applied to wrappers of smoking articles
as a single continuous band, the smoking articles would exhibit statistically few
or no occurrences of total burn through and statistically significant occurrences
of self-extinguishment under free burn conditions,
so that lit smoking articles comprising said first (11)(21)(31), second (12)(22)(32)
and third (13)(23)(33) zones exhibit statistically reduced occurrences of self-extinguishment
under free burn conditions, as compared to smoking articles comprising wrappers whereon
the first and third zones are applied as a single continuous band, while maintaining
statistically few or no occurrences of total burn through.
2. A wrapper according to any preceding claim wherein the first (11)(21)(31) and third
(13)(23)(33) zones of add-on material are each 2 mm to 3 mm, preferably about 3 mm,
wide.
3. A wrapper according to claim 1 or 2 wherein the said second zone (12)(22)(32) is 1
mm to 2 mm wide, preferably about 1 mm or 1.5 mm wide.
4. A wrapper according to claim 1, 2 or 3 wherein the first (11)(21)(31) and third (13)(23)(33)
zones have a greater basis weight in grams per square meter than the second zone (12)(22)(32).
5. A wrapper according to any preceding claim wherein the basis weight in grams per square
meter of the first (11)(21)(31) and third zones (13)(23)(33) is at least twice the
basis weight in grams per square meter of the second zone (12)(22)(32).
6. A wrapper according to any preceding claim wherein the second zone (12)(22)(32) comprises
no add-on material.
7. A wrapper according to any preceding claim wherein the at least one transverse banded
region (10)(20)(30) comprises a first printed layer contacting the base web and a
second printed layer on the first printed layer.
8. A wrapper according to any preceding claim wherein the at least one transverse banded
region (10)(20)(30) is a high-solids-content occlusive composition.
9. A wrapper according to claim 8 wherein the said high-solids-content occlusive composition
has a viscosity at about 23°C exceeding about 2 mPa·s (200 centipoise) and the viscosity
at 40°C to 90°C is decreased sufficiently for use of the said composition as a gravure
printing composition, preferably about 1 mPa·s (100 cP).
10. A wrapper according to any preceding claim wherein the transverse banded regions (10)(20)(30)
comprise first (21), third (23) and fifth (25) zones of add-on material separated
by second (22) and fourth (24) zones of no or lower levels of add-on material.
11. A wrapper according to claim 10 wherein the first (21), third (23) and fifth (25)
zones are from 2 mm to 3 mm, preferably 2 mm, wide.
12. A wrapper according to claim 10 or 11 wherein the second (22) and fourth (24) zones
are 1 mm to 2 mm wide.
13. A wrapper according to any preceding claim wherein the total weight of add-on material
for the said transverse banded region (10)(20)(30) is 0.5 g/m2 to 15 g/m2, preferably 0.5 g/m2 to 3 g/m2, more preferably 0.5 g/m2 to 1.5 g/m2.
14. A wrapper according to any preceding claim wherein the permeability of the base web
(100) exceeds 20 CORESTA, preferably is 33 CORESTA to 60 CORESTA.
15. A wrapper according to any preceding claim wherein the basis weight of the base web
(100) is 22 g/m2 to 30 g/m2.
16. A wrapper according to any preceding claim wherein the permeability of the transverse
banded regions (10)(20)(30) and the underlying cigarette paper (100) is 0 to 15 CORESTA.
17. A method of making a banded wrapper according to any preceding claim comprising:
supplying a base web (100); and
forming at least one transverse banded region (10)(20)(30) comprising first (11)(21)(31),
second (12)(22)(32) and third (13)(23)(33) zones on the base web;
wherein the first (11)(21)(31) and third (13)(23)(33) zones are outward of the second
(12)(22)(32) zone,
wherein the second zone (12)(22)(32) has a greater permeability compared to the first
(11)(21)(31) and third (13)(23)(33) zones,
wherein the width of the second zone (12)(22)(32) is less than those of the first
(11)(21)(31) and third (13)(23)(33) zones, characterised in that
the first (11)(21)(31) and third (13)(23)(33) zones are formed so that the add-on
material is uniform across each of the first and third zones and in that
the first (11)(21)(31) and third (13)(23)(33) zones are formed so that each of the
first and third zones has a width of 2 mm to 5 mm such that if either of said first
or third zone were applied separately to wrappers of smoking articles the smoking
articles would exhibitstatistically significant occurrences of total burn through
and statistically few or no occurrences of self-extinguishment under free burn conditions.
18. A method according to claim 17 comprising forming at least the first (11)(21)(31)
and third (13)(23)(33) zones by printing a first printed layer of add-on material
on the base web (100).
19. A method according to claim 17 or 18 wherein the at least one transverse banded region
(10)(20)(30) is formed by printing an occlusive material on the base web (100).
20. A method according to claim 18 wherein the printing comprises:
heating the occlusive material;
applying the heated occlusive material to a patterned gravure cylinder;
contacting the advancing wrapper with the patterned gravure cylinder; and
gelling the occlusive material by contact with the wrapper surface so that the occlusive
material does not disrupt planarity of the wrapper.
21. A method according to any of claims 17 to 20 wherein at least the first (11)(21)(31)
and third (13)(23)(33) zones are formed from an add-on material free of fillers.
1. Umhüllung für einen Rauchartikel, umfassend:
eine Grundbahn (100); und
wenigstens eine quergebänderte Region (10)(20)(30), die eine erste (11)(21)(31), zweite
(12)(22)(32) und dritte (13)(23)(33) Zone umfasst,
wobei die genannte erste (11)(21)(31) und dritte (13)(23)(33) Zone Zusatzstoff aufweisen,
der die Durchlässigkeit der genannten Umhüllung reduziert, wobei die genannte erste
und dritte Zone durch die genannte zweite Zone (12)(22)(32) getrennt sind,
wobei die genannte Umhüllung eine höhere Durchlässigkeit entlang der genannten zweiten
Zone (12)(22)(32) aufweist als entlang der genannten ersten (11)(21)(31) und dritten
(13)(23)(33) Zone, wobei die genannte zweite Zone eine Breite aufweist, die geringer
ist als die Breite der genannten ersten und dritten Zone, dadurch gekennzeichnet, dass
der Zusatzstoff über jede der ersten (11)(21)(31) und dritten (13)(23)(33) Zonen gleichförmig
ist;
die genannte erste (11)(21)(31) und dritte (13)(23)(33) Zone jeweils eine Breite von
2 mm bis 5 mm aufweisen, sodass die Rauchartikel, wenn entweder die genannte erste
oder die genannte dritte Zone separat auf Umhüllungen von Rauchartikeln aufgebracht
würden, ein vollständiges Durchbrennen und im Wesentlichen kein Auftreten von Selbstverlöschung
unter freien Brennbedingungen aufweisen würden;
die Summe der genannten Breiten der genannten ersten (11)(21)(31) und dritten (13)(23)(33)
Zonen derart ist, dass die Rauchartikel, wenn die erste und dritte Zone auf Umhüllungen
von Rauchartikeln als einzelner kontinuierlicher Streifen aufgebracht würden, im Wesentlichen
kein Auftreten von vollständigem Durchbrennen und Selbstverlöschung unter freien Brennbedingungen
aufweisen würden,
sodass angezündete Rauchartikel, die die genannte erste (11)(21)(31), zweite (12)(22)(32)
und dritte (13)(23)(33) Zone aufweisen, im Vergleich zu Rauchartikeln, die Umhüllungen
umfassen, bei denen die erste und die dritte Zone als ein einziger kontinuierlicher
Streifen aufgebracht sind, ein vermindertes Auftreten von Selbstverlöschung unter
freien Brennbedingungen zeigen, während sie im Wesentlichen kein Auftreten von vollständigem
Durchbrennen aufweisen.
2. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei die erste (11)(21)(31)
und die dritte (13)(23)(33) Zone aus Zusatzstoff eine Breite von jeweils 2 mm bis
3 mm, bevorzugt etwa 3 mm, aufweisen.
3. Umhüllung nach Anspruch 1 oder 2, wobei die zweite Zone (12)(22)(32) eine Breite von
1 mm bis 2 mm, bevorzugt etwa 1 mm oder 1,5 mm, aufweist.
4. Umhüllung nach Anspruch 1, 2 oder 3, wobei die erste (11)(21)(31) und dritte (13)(23)(33)
Zone ein größeres Flächengewicht in Gramm pro Quadratmeter aufweisen als die zweite
Zone (12)(22)(32) .
5. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei das Flächengewicht
in Gramm pro Quadratmeter der ersten (11)(21)(31) und dritten Zone (13)(23)(33) wenigstens
das Zweifache des Flächengewichts in Gramm pro Quadratmeter der zweiten Zone (12)(22)(32)
beträgt.
6. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei die zweite Zone (12)(22)(32)
keinen Zusatzstoff aufweist.
7. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei die wenigstens eine
quergebänderte Region (10)(20)(30) eine erste gedruckte Schicht in Kontakt mit der
Grundbahn und eine zweite gedruckte Schicht auf der ersten gedruckten Schicht aufweist.
8. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei die wenigstens eine
quergebänderte Region (10)(20)(30) eine okklusive Zusammensetzung mit hohem Feststoffgehalt
ist.
9. Umhüllung nach Anspruch 8, wobei die okklusive Zusammensetzung mit hohem Feststoffgehalt
eine Viskosität bei etwa 23 °C von mehr als etwa 2 mPa-s (200 Centipoise) aufweist
und die Viskosität bei 40 °C bis 90 °C ausreichend zum Gebrauch der genannten Zusammensetzung
als Tiefdruckzusammensetzung verringert ist, bevorzugt etwa 1 mPa-s (100 cP).
10. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei die quergebänderten
Regionen (10)(20)(30) ein erste (21), eine dritte (23) und eine fünfte (25) Zone mit
Zusatzstoff aufweisen, die durch eine zweite (22) und eine vierte (24) Zone ohne oder
mit geringerer Zusatzstoffkonzentration getrennt sind.
11. Umhüllung nach Anspruch 10, wobei die erste (21), die dritte (23) und die fünfte (25)
Zone eine Breite von 2 mm bis 3 mm, bevorzugt 2 mm, aufweisen.
12. Umhüllung nach Anspruch 10 oder 11, wobei die zweite (22) und vierte (24) Zone eine
Breite von 1 mm bis 2 mm aufweisen.
13. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei das Gesamtgewicht des
Zusatzstoffs für die quergebänderte Region (10)(20)(30) 0,5 g/m2 bis 15 g/m2, bevorzugt 0,5 g/m2 bis 3 g/m2, noch bevorzugter 0,5 g/m2 bis 1,5 g/m2 beträgt.
14. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei die Durchlässigkeit
der Grundbahn (100) 20 CORESTA übersteigt, bevorzugt 33 CORESTA bis 60 CORESTA beträgt.
15. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei das Flächengewicht
der Grundbahn (100) 22 g/m2 bis 30 g/m2 beträgt.
16. Umhüllung nach einem beliebigen vorhergehenden Anspruch, wobei die Durchlässigkeit
der quergebänderten Regionen (10)(20)(30) und des darunter liegenden Zigarettenpapiers
(100) 0 bis 15 CORESTA beträgt.
17. Verfahren zur Herstellung einer gebänderten Umhüllung nach einem beliebigen vorhergehenden
Anspruch, umfassend:
Zuführen einer Grundbahn (100); und
Bilden wenigstens einer quergebänderten Region (10)(20)(30), umfassend erste (11)(21)(31),
zweite (12)(22)(32) und dritte (13)(23)(33) Zonen auf der Grundbahn;
wobei sich die erste (11)(21)(31) und dritte (13) (23) (33) Zone außerhalb der zweiten
(12)(22)(32) Zone befinden,
wobei die zweite Zone (12)(22)(32) im Vergleich zu der ersten (11)(21)(31) und der
dritten (13)(23)(33) Zone eine höhere Durchlässigkeit aufweist,
wobei die Breite der zweiten Zone (12)(22)(32) geringer ist als die der ersten (11)(21)(31)
und dritten (13)(23)(33) Zone, dadurch gekennzeichnet, dass
die erste (11)(21)(31) und dritte (13)(23)(33) Zone derart geformt sind, dass der
Zusatzstoff gleichförmig über jede der ersten und dritten Zonen ist, und dadurch,
dass
die erste (11)(21)(31) und die dritte (13)(23)(33) Zone derart gebildet sind, dass
jede der ersten und dritten Zonen eine Breite von 2 mm bis 5 mm aufweist, sodass die
Rauchartikel, wenn entweder die genannte erste oder dritte Zone separat auf Umhüllungen
von Rauchartikeln aufgebracht würde, ein vollständiges Durchbrennen und im Wesentlichen
kein Auftreten von Selbstverlöschung unter freien Brennbedingungen aufweisen würden.
18. Verfahren nach Anspruch 17, umfassend das Bilden wenigstens der ersten (11)(21)(31)
und der dritten (13)(23)(33) Zone durch Drucken einer ersten gedruckten Schicht von
Zusatzstoff auf die Grundbahn (100).
19. Verfahren nach Anspruch 17 oder 18, wobei die wenigstens eine quergebänderte Region
(10)(20)(30) durch Drucken eines okklusiven Materials auf die Grundbahn (100) gebildet
wird.
20. Verfahren nach Anspruch 18, wobei das Drucken umfast:
Erwärmen des okklusiven Materials;
Aufbringen des erwärmten okklusiven Materials auf einen gemusterten Tiefdruckzylinder;
Inkontaktbringen der vorlaufenden Umhüllung mit dem gemusterten Tiefdruckzylinder;
und
Gelieren des okklusiven Materials durch Inkontaktbringen mit der Umhüllungsfläche,
sodass das okklusive Material die Ebenheit der Umhüllung nicht stört.
21. Verfahren nach einem der Ansprüche 17 bis 20, wobei wenigstens die erste (11)(21)(31)
und dritte (13)(23)(33) Zone aus einem füllstofffreien Zusatzstoff gebildet sind.
1. Enveloppe d'un article à fumer, comprenant :
une feuille de base (100) ; et
au moins une région rayée transversale (10)(20)(30) comprenant une première (11)(21)(31),
une deuxième (12)(22)(32) et une troisième (13)(23)(33) zones,
lesdites première (11)(21)(31) et troisième (13)(23)(33) zones comprenant une matière
additionnelle qui réduit la perméabilité de ladite enveloppe, lesdites première et
troisième zones étant séparées par ladite deuxième zone (12)(22)(32),
ladite enveloppe ayant une plus grande perméabilité le long de ladite deuxième zone
(12)(22)(32) que le long desdites première (11)(21)(31) et troisième (13)(23)(33)
zones, ladite deuxième zone ayant une largeur moindre que la largeur de l'une ou l'autre
desdites première et troisième zones,
la matière additionnelle étant uniforme d'un côté à l'autre de chacune des première
(11)(21)(31) et troisième (13)(23)(33) zones ;
lesdites première (11)(21)(31) et troisième (13)(23)(33) zones ont chacune une largeur
de 2 mm à 5 mm de telle sorte que si soit ladite première zone soit ladite troisième
zone était appliquée séparément aux enveloppes d'articles à fumer, les articles à
fumer présenteraient une combustion totale et sensiblement aucune occurrence d'auto-extinction
dans des conditions de combustion libre ;
la somme desdites largeurs desdites première (11)(21)(31) et troisième (13(23)(33)
zones est telle que si les première et troisième zones étaient appliquées à des enveloppes
d'articles à fumer comme une seule bande continue, les articles à fumer ne présenteraient
sensiblement aucune occurrence de combustion totale et d'auto-extinction dans des
conditions de combustion libre,
de telle sorte que des articles à fumer allumés comprenant lesdites première (11)(21)(31),
deuxième (12)(22)(32) et troisième (13)(23)(33) zones présentent des occurrences réduites
d'auto-extinction dans des conditions de combustion libre, comparés à des articles
à fumer comprenant des enveloppes sur lesquelles les première et troisième zones sont
appliquées comme une seule bande continue, tout en maintenant sensiblement aucune
occurrence de combustion totale.
2. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle les
première (11)(21)(31) et troisième (13)(23)(33) zones de matière additionnelle ont
chacune une largeur de 2 mm à 3 mm et de préférence d'environ 3 mm.
3. Enveloppe selon la revendication 1 ou 2, dans laquelle ladite deuxième zone (12)(22)(32)
a une largeur de 1 mm à 2 mm, de préférence d'environ 1 mm ou 1,5 mm.
4. Enveloppe selon la revendication 1, 2 ou 3, dans laquelle les première (11)(21)(31)
et troisième (13)(23)(33) zones ont un plus grand grammage en grammes par mètre carré
que la deuxième zone (12) (22) (32) .
5. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle le
grammage en grammes par mètre carré des première (11)(21)(31) et troisième (13)(23)(33)
zones fait au moins deux fois le grammage en grammes par mètre carré de la deuxième
zone (12)(22)(32).
6. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle la
deuxième zone (12)(22)(32) ne comprend pas de matière additionnelle.
7. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle l'au
moins une région rayée transversale (10)(20)(30) comprend une première couche imprimée
en contact avec la feuille de base et une deuxième couche imprimée sur la première
couche imprimée.
8. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle l'au
moins une région rayée transversale (10)(20)(30) est une composition occlusive à haute
teneur en solides.
9. Enveloppe selon la revendication 8, dans laquelle ladite composition occlusive à haute
teneur en solides a une viscosité à environ 23 °C dépassant environ 2 mPa·s (200 centipoises)
et la viscosité de 40 °C à 90 °C est suffisamment réduite pour utiliser ladite composition
comme une composition de héliogravure, de préférence d'environ 1 mPa·s (100 cP).
10. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle les
régions rayées transversales (10)(20)(30) comprennent des première (21), troisième
(23) et cinquième (25) zones de matière additionnelle séparées par des deuxième (22)
et quatrième (24) zones sans ou à de moindres niveaux de matière additionnelle.
11. Enveloppe selon la revendication 10, dans laquelle les première (21), troisième (23)
et cinquième (25) zones ont une largeur de 2 mm à 3 mm, de préférence 2 mm.
12. Enveloppe selon la revendication 10 ou 11, dans laquelle les deuxième (22) et quatrième
(24) zones ont une largeur de 1 mm à 2 mm.
13. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle le
poids total de matière additionnelle pour ladite région rayée transversale (10)(20)(30)
est de 0,5 g/m2 à 15 g/m2, de préférence de 0,5 g/m2 à 3 g/m2, de manière davantage préférée de 0,5 g/m2 à 1,5 g/m2.
14. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle la
perméabilité de la feuille de base (100) dépasse 20 CORESTA, est de préférence de
33 CORESTA à 60 CORESTA.
15. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle le
grammage de la feuille de base (100) est de 22 g/m2 à 30 g/m2.
16. Enveloppe selon l'une quelconque des revendications précédentes, dans laquelle la
perméabilité des régions rayées transversales (10)(20)(30) et du papier à cigarette
sous-jacent (100) est de 0 à 15 CORESTA.
17. Procédé de fabrication d'une enveloppe rayée selon l'une quelconque des revendications
précédentes, comprenant :
la fourniture d'une feuille de base (100) ; et
la formation d'au moins une région rayée transversale (10)(20)(30) comprenant des
première (11)(21)(31), deuxième (12)(22)(32) et troisième (13)(23)(33) zones sur la
feuille de base ;
dans lequel les première (11)(21)(31) et troisième (13)(23)(33) zones sont à l'extérieur
de la deuxième zone (12)(22)(32),
dans lequel la deuxième zone (12)(22)(32) a une plus grande perméabilité comparée
aux première (11)(21)(31) et troisième (13)(23)(33) zones,
dans lequel la largeur de la deuxième zone (12)(22)(32) est moindre que celles des
première (11)(21)(31) et troisième (13)(23)(33) zones, caractérisé en ce que
les première (11)(21)(31) et troisième (13)(23)(33) zones sont formées de telle sorte
que la matière additionnelle est uniforme d'un côté à l'autre des première et troisième
zones, et en ce que
les première (11)(21)(31) et troisième (13)(23)(33) zones sont formées de telle sorte
que chacune de la première et de la troisième zones a une largeur de 2 mm à 5 mm de
telle sorte que si soit ladite première zone soit ladite troisième zone était appliquée
séparément aux enveloppes d'articles à fumer, les articles à fumer présenteraient
une combustion totale et sensiblement aucune occurrence d'auto-extinction dans des
conditions de combustion libre.
18. Procédé selon la revendication 17, comprenant la formation d'au moins les première
(11)(21)(31) et troisième (13)(23)(33) zones en imprimant une première couche imprimée
de matière additionnelle sur la feuille de base (100).
19. Procédé selon la revendication 17 ou 18, dans lequel l'au moins une région rayée transversale
(10) (20) (30) est formée en imprimant une matière occlusive sur la feuille de base
(100).
20. Procédé selon la revendication 18, dans lequel l'impression comprend :
le chauffage de la matière occlusive ;
l'application de la matière occlusive chauffée à un cylindre d'héliogravure à motifs
;
la mise en contacte de l'enveloppe qui avance avec le cylindre d'héliogravure à motifs
; et
la gélification de la matière occlusive par contact avec la surface de l'enveloppe
de telle sorte que la matière occlusive ne rompt pas la planarité de l'enveloppe.
21. Procédé selon l'une quelconque des revendications 17 à 20, dans lequel au moins les
première (11) (21) (31) et troisième (13)(23)(33) zones sont formées en une matière
additionnelle dépourvue de charge.