U.S. patent application number 16/342358 was filed with the patent office on 2019-08-08 for a smoking article with liquid-filled capsule.
This patent application is currently assigned to JT International S.A.. The applicant listed for this patent is JT International S.A.. Invention is credited to Hiroyoshi Ono.
Application Number | 20190239558 16/342358 |
Document ID | / |
Family ID | 57223549 |
Filed Date | 2019-08-08 |
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United States Patent
Application |
20190239558 |
Kind Code |
A1 |
Ono; Hiroyoshi |
August 8, 2019 |
A Smoking Article With Liquid-filled Capsule
Abstract
A smoking article includes a rod element including smokeable
material and a filter element having a first end for connection to
an end of the rod element and an opposite, second end for insertion
into a mouth of a user. A liquid-filled capsule is arranged between
the first and second ends of the filter element and the
liquid-filled capsule is configured to break upon application of an
external force to release the liquid. A tipping wrapper connects
the filter element and rod element. The tipping wrapper has a wet
tensile strength of at least about 0.15 kN/m. The smoking article
is resistant to breakage even after the liquid is released.
Inventors: |
Ono; Hiroyoshi; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JT International S.A. |
Geneva |
|
CH |
|
|
Assignee: |
JT International S.A.
Geneva
CH
|
Family ID: |
57223549 |
Appl. No.: |
16/342358 |
Filed: |
October 30, 2017 |
PCT Filed: |
October 30, 2017 |
PCT NO: |
PCT/EP2017/077818 |
371 Date: |
April 16, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A24D 3/14 20130101; A24D
1/025 20130101; A24D 3/10 20130101; A24D 3/061 20130101; A24D 3/063
20130101; A24D 1/02 20130101 |
International
Class: |
A24D 3/06 20060101
A24D003/06; A24D 1/02 20060101 A24D001/02; A24D 3/14 20060101
A24D003/14; A24D 3/10 20060101 A24D003/10 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2016 |
EP |
16196649.4 |
Claims
1. A smoking article, comprising: a rod element comprising
smokeable material; a filter element having a first end for
connection to an end of the rod element and an opposite, second end
for insertion into a mouth of a user; a liquid-filled capsule
arranged between the first and second ends of the filter element,
the liquid-filled capsule configured to break upon application of
an external force to release liquid contained therein; and a
tipping wrapper which connects the filter element and the rod
element; wherein the tipping wrapper has a wet tensile strength of
at least 0.15 kN/m.
2. The smoking article according to claim 1, wherein the tipping
wrapper has a dry tensile strength of at least 1 kN/m.
3. The smoking article according to claim 2, wherein the dry
tensile strength of the tipping wrapper is no more than 5 kN/m.
4. The smoking article according to claim 1, wherein the wet
tensile strength of the tipping wrapper is no more than 0.55
kN/m.
5. The smoking article according to claim 2, wherein a dry tensile
strength to wet tensile strength ratio is no more than 15.
6. The smoking article according to claim 1, wherein the tipping
wrapper is wrapped about the filter element such that a principal
stress direction of the tipping wrapper is substantially parallel
to a longitudinal axis of the filter element.
7. The smoking article according to claim 6, wherein the principal
stress direction is a cross direction parallel to a longitudinal
axis of a roll of tipping wrapper material.
8. The smoking article according to claim 1, wherein the
liquid-filled capsule is a directional capsule.
9. The smoking article according to claim 8, wherein the
directional capsule comprises a predefined rupture region
configured to break upon application of the external force, and the
rupture region is directed towards the first end of the filter
element.
10. The smoking article according to claim 8, wherein the
directional capsule comprises a predefined rupture region
configured to break upon application of the external force, and the
rupture region is directed towards the second end of the filter
element.
11. The smoking article according to claim 1, wherein the filter
element further comprises fibrous filtration material between the
capsule and the first end of the filter element.
12. The smoking article according to claim 11, wherein the fibrous
filtration material extends between the capsule and the first end
of the filter element at least 7 mm.
13. The smoking article according to claim 1, wherein the capsule
contains a liquid volume of at least 0.05 ml.
14. The smoking article according to claim 1, wherein the tipping
wrapper comprises: fibrous material; and a wet-strength additive
which acts to increase bonding between fibres of the fibrous
material.
15. The smoking article according to claim 14, wherein the fibrous
material is paper, and the wet-strength additive is selected from a
natural resin, a synthetic resin, or a combination thereof.
Description
TECHNICAL FIELD
[0001] The present invention relates to a smoking article which
includes a filter element having a liquid-filled capsule. The
characteristics of the smoke produced by the smoking article may be
altered by breaking the capsule to release the liquid within the
smoking article. The smoking article is configured to withstand
breakage, even after wetting of the article following release of
the liquid from the capsule.
BACKGROUND
[0002] Smoking articles, such as cigarettes, cigarillos or the
like, are popular consumer products that typically have a generally
cylindrical rod shaped configuration and include a charge, roll, or
column of smokeable material, such as shredded tobacco (e.g. in cut
filler form), which is surrounded by a paper wrapper forming a
so-called "tobacco rod". A cigarette or cigarillo usually also has
a cylindrical filter element aligned in end-to-end relationship
with the tobacco rod. The filter element may, for example, comprise
a plug of cellulose acetate tow, and the tow is circumscribed by a
wrapper material known as "plug wrap". Typically, the filter
element is attached to one end of the tobacco rod using a
circumscribing wrapping material known as "tipping wrapper". The
filter element wrapped by the tipping wrapper is known as a
"mouthpiece element".
[0003] In recent years there has been increasing consumer demand
for smoking articles providing modified sensory attributes, and
particularly for cigarettes incorporating filter elements, which
may act as vehicles for adding flavour to mainstream smoke of the
cigarettes. Specifically, these smoking articles have included
flavour-altering substances in breakable pellets or capsules.
During cigarette manufacture, the filter material is formed into a
continuous filter rod having such pellets or capsules positioned
within that rod; e.g., along a longitudinal axis thereof. The
continuous filter rod is then divided or cut at predetermined
intervals to form a plurality of filter elements, such that each
filter element includes at least one of the capsules. The capsules
are then manually broken by the consumer to release a substance
into the filter material which acts to alter one or more
characteristics of the mainstream smoke during smoking, such as
flavour, taste, or TNCO levels (tar, nicotine, CO).
[0004] For this purpose, breakable capsules having a shell, e.g.
made of gel, containing the substance to be released have been
used. Most recently, such breakable capsules have started to focus
on liquid release, especially water release. This can become
problematic, however, as the released liquid tends to soak the
filter element, including the filter wrapper and the tipping
wrapper that joins the filter element to the tobacco rod, which may
be weakened. As a result, when a force is applied, for example when
the user taps the mouthpiece element to remove the ashes from the
lit end of the smoking article, the mouthpiece element may snap off
the tobacco rod, especially at the connection between the tobacco
rod and filter where a portion of the tipping wrapper overwraps the
tobacco rod.
[0005] It is therefore an object of the invention to provide a
smoking article with a liquid-filled capsule that can withstand
damage under the application of an external force, even after
wetting of the smoking article following liquid release. In
particular it is desirable to provide a smoking article which
mitigates the risk of the mouthpiece element detaching when the
consumer taps the mouthpiece element to remove the ashes at the lit
end of the smoking article.
SUMMARY OF THE INVENTION
[0006] According to an aspect of the present invention there is
provided a smoking article comprising a rod element comprising
smokeable material (e.g. a tobacco rod); a filter element having a
first end for connection to an end of the rod element and an
opposite, second end for insertion into a mouth of a user; a
liquid-filled capsule arranged between the first and second ends of
the filter element, the liquid-filled capsule configured to break
upon application of an external force to release liquid contained
therein; and a tipping wrapper which connects the filter element
and rod element; wherein the tipping wrapper has a wet tensile
strength of at least about 0.15 kN/m.
[0007] The wet tensile strength of the tipping wrapper is selected
to ensure that the smoking article can sustain forces experienced
during normal use without damage to the components of the smoking
article, even after release of the liquid from the capsule. In
particular, it has been determined that by using tipping wrapper
with a wet tensile strength of 0.15 kN/m or greater, the smoking
article is robust to forces associated with use of the smoking
article. For example the article may be robust enough to withstand
the repetitive forces associated with a user tapping the mouthpiece
to remove ash during use. The wet tensile strength may be of at
least 0.20 kN/m, for example of at least 0.25 kN/m, such as of at
least 0.30 kN/m, or of at least 0.35 kN/m. The wet tensile strength
may be of no more than 0.55 kN/m, such as no more than 0.50 kN/m,
for example of no more than 0.45 kN/m, or 0.40 kN/m or less.
[0008] The tipping wrapper may have a dry tensile strength of at
least 1 kN/m, for example of at least 1.25 kN/m, of at least 1.50
kN/m, such as of at least 1.75 kN/m, or of at least 2 kN/m. By
using a tipping wrapper which has a dry tensile strength of 1 kN/m
or more (i.e. prior to wetting with the released liquid), the
tipping wrapper can withstand pulling forces to which is subject
during manufacturing, especially when the tipping wrapper is
provided in a reel and, to connect the filter element to the rod
element of smokeable material, is pulled from the reel and wrapped
about the filter and tobacco at high speed.
[0009] The tipping wrapper may have a dry tensile strength of less
than 5 kN/m, for example less than 4 kN/m, such as of less than 3
kN/m.
[0010] The tipping wrapper may have a dry tensile strength to wet
tensile strength ratio of no more than 15, for example less than
12, such as less than 9 or less than 6. The tipping wrapper may
have a ratio of dry tensile strength to wet tensile strength
between 4 and 15, for example of between 5 and 9, such as of
between 5 and 7.
[0011] The tensile strengths of the tipping wrapper, wet and dry,
are measured along a principal stress direction of the tipping
wrapper, which correspond to a set of mutually perpendicular axes
where the normal stress tensor is maximised. The wet tensile
strength is measured according to ISO 3781:1983, while dry tensile
strength is measured according to ISO 1924-2:2008. The principal
stress directions in a roll of tipping wrapper material, such as a
paper roll of tipping wrapper (i.e. a roll of tipping paper), are
called machine direction (MD), cross direction (CD), and
z-direction (ZD), and have been represented in FIG. 1. Both the
machine direction and the cross direction are contained in the
plane of the tipping wrapper material; the machine direction being
the direction in which the material is pulled from the roll, and
the cross direction parallel to the longitudinal axis of the roll
and oriented in the winding direction of the roll. The z-direction
is perpendicular to the plane of the tipping wrapper material and,
therefore, to the other two principal directions. When the roll of
tipping wrapper material is wound, the z-direction points radially
towards the longitudinal axis of the roll. Preferably, wet and dry
tensile strength measurements are conducted along the machine
direction.
[0012] The tipping wrapper is preferably wrapped about the filter
element with a principal stress direction substantially parallel to
a longitudinal axis of the filter element. Preferably, this
principal stress direction is the cross direction, as, generally,
the machine direction has a higher tensile strength than the cross
direction, and this eases manufacturing at high speed, as explained
above.
[0013] The liquid-filled capsule may be an isotropic capsule
configured to break upon the application of a predetermined
compressive force. The liquid-filled capsule may break to release
the liquid uniformly or in one or more directions. The
liquid-filled capsule may be a spherical capsule.
[0014] The liquid-filled capsule may be a directional capsule, a
directional capsule being a capsule containing a volume of liquid
that is adapted to direct liquid release into a particular desired
direction or towards a particular desired region.
[0015] The directional capsule may be configured to break at a
predetermined rupture region upon application of the external force
to release the liquid substantially from the rupture region. The
use of a tipping wrapper having a wet tensile strength of 0.15 kN/m
or greater is particularly important when a directional capsule is
used because released liquid is directed into a particular area of
the article. By providing a relatively high tensile strength in the
tipping wrapper in this area the smoking article may have an
improved robustness against breakage.
[0016] The rupture region of the capsule may be arranged to release
the liquid in an axial direction, such as a longitudinal axis of
the filter element.
[0017] Some breakable capsules have an isotropic resistance to
break, which may result in a difficulty in determining the specific
rupture location of the capsule, and accordingly the region of the
filter element into which the contained substance is released. With
a directional capsule liquid is released into a predetermined
portion of the article, which can be strengthened within the
defined tipping wrapper, thereby mitigating the effects of damage.
Certain directional capsules can eject liquid in a jet, the force
of which may depend on the crushing force applied by the consumer.
Thus, liquid may be propelled away from the directional capsule
with a degree of force, which may extend the wetting of the smoking
article further towards the tobacco end than may be typical with
non-directional capsules. This only increases the importance of
providing the tipping wrapper with a relatively high wet tensile
strength, which is greater than 0.15 kN/m.
[0018] The use of a directional capsule may also influence the
position in the smoking article in which the liquid is released
which can have an impact on the changes in smoke characteristics,
such as flavour, provided by the liquid. Therefore control over the
location in which the liquid is released may also be important in
order to provide better control on the effects of the liquid on the
inhaled smoke.
[0019] The rupture region may be directed towards the first end of
the filter element. Thus, liquid may be deposited close to the
connection end of the rod element. However, as described, this area
may be particularly susceptible to weakening via the absorption of
released liquid and therefore this may increase the likelihood of
rod detachment. The use of the tipping wrapper with a wet tensile
strength of more than 0.15 kN/m in this region can help to ensure
that the rod is not detached in normal use.
[0020] The rupture region may be directed towards the second end of
the filter element. In this way, the liquid may be directed away
from the area of the article most susceptible to weakening after
wetting.
[0021] The filter element may further comprise fibrous filtration
material between the capsule and the first end of the filter
element. By providing fibrous filtration material upstream of the
directional capsule, the effect of the released liquid on the
characteristics of the mainstream smoke is prolonged in time. The
fibrous filtration material may be arranged immediately adjacent
the directional capsule, for example immediately adjacent the
rupture region of the directional capsule. By arranging the fibrous
filtration material immediately adjacent the directional capsule,
progression of liquid towards the weakest region of the smoking
article, the region where the tipping wrapper solely overlies the
rod element of smokeable material (connection region), can be
controlled. The fibrous filtration material may extend at least 7
mm, for example 9 mm, between the directional capsule and the first
end of the filter element. By providing this amount of fibrous
filtration material immediately upstream of the directional capsule
liquid leakage is mitigated and the effect of the released liquid
on the characteristics of the mainstream smoke is prolonged in
time.
[0022] In one arrangement the capsule may contain a liquid volume
of at least 0.05 ml. In another arrangement the capsule may contain
a volume of at least 0.07 ml or at least 0.08 ml. This volume of
liquid may be significantly greater than known devices. The use of
a high volume capsule only increases problems that may be
experienced in the smoking article due to wetting. Therefore, this
provides a further advantage for the use of a relatively high wet
tensile strength tipping wrapper, which is greater than 0.15
kN/m.
[0023] In a preferred arrangement the volume of liquid in the
directional capsule may be no more than 0.15 ml, for example no
more than 0.12 ml, or no more than 0.10 ml. By providing such
volume of liquid, liquid leakage is mitigated further.
[0024] The tipping wrapper may comprise fibrous material and a
wet-strength additive which acts to increase the bonding between
the fibres of the fibrous material. The additive may be added
during manufacture, such as during the curing process, so as to be
embedded in the fibres. The increased bonding between fibres may be
facilitated by cross-linking of the molecules of the additive. By
adding a wet-strength additive to increase the bonding between the
fibres, the wet tensile strength of the tipping wrapper may be
increased. In some arrangements the fibrous material may be paper,
and the wet-strength additive may be a polymer. The wet-strength
additive may be selected from a natural resin, a synthetic resin,
or a combination of them.
[0025] The filter element may further comprise a filter wrapper at
least partly extending between the first and second ends of the
filter element. The provision of such a filter wrapper may aid to
retain the liquid within the filter element and, thus, mitigate
still further leakage, as well further prolong in time the effect
on the characteristics of the mainstream smoke. By providing such
filter wrapper, the weakest region of the smoking article after
liquid release is further localised at the connection between the
filter and rod element provided by the tipping wrapper and
accordingly results in further strengthening the smoking article
against the weakening effects of the released liquid.
[0026] The filter element may comprise at least two filter segments
combined by the filter wrapper. In this way, the capsule may be
provided within one such filter segment and filtration material may
be provided in one or more further filter segments, which may
simplify manufacture of the smoking article.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Embodiments of the invention will now be described, by way
of example only, with reference to the accompanying drawings, in
which:
[0028] FIG. 1 shows the principal stress directions in a roll of
tipping wrapper material;
[0029] FIG. 2 is a side cross-sectional view of a filter element
for use in a smoking article in an embodiment of the present
invention;
[0030] FIG. 3 is a side view of a smoking article in an embodiment
of the present invention; and
[0031] FIG. 4 is an isometric view of a smoking article in an
embodiment of the present invention showing filter and tipping
wrappers in an unwrapped condition.
DETAILED DESCRIPTION
[0032] FIG. 3 is a schematic side view of a smoking article 10 in
an embodiment of the present invention. The smoking article 10
comprises a rod element 11, containing a smokeable material,
connected to a filter element 1. The filter element has a first end
2 for connection to an end of the rod element 11 and a second end 3
through which smoke is inhaled into the mouth of a user. A
liquid-filled capsule 7 is provided between the first 2 and second
3 ends of the filter element 1. The liquid filled capsule 7 is
configured to break upon application of a force F to release a
liquid L. The rod 11 and filter 1 elements are connected in a
linearly aligned relationship with a tipping wrapper 12 which
extends over at least the connected ends. The tipping wrapper 12
has a wet tensile strength of at least 0.15 kN/m, preferably of at
least 0.20 kN/m.
[0033] The tipping wrapper 12 may be made of fibrous material such
as paper that comprises a wet-strength additive. The wet-strength
additive may include at least one of a natural polymer, such as
starch or carboxymethylcellulose (CMC), or a synthetic resin, such
as polyacrylamide (PAM), glyoxalated polyacrylamide (GPAM), or
polyamide-epichlorohydrin (PAE). These resins typically work during
the curing process of the paper, when the functional groups on the
polymer react with cellulose fiber to form a covalent bond. The
polymer molecules cross-link, forming a network in the cellulose
web that provides strength when the paper becomes wet. Wet-strength
additives can also reinforce existing fibre-to-fibre bonds, which
further enhance the strength of the paper. The wet-strength
additive may be applied in a quantity sufficient to saturate the
cellulose fibres.
[0034] The rod element 11 is a tobacco rod and the smokeable
material comprises tobacco. For example, the smokeable material may
be cut filler tobacco. The cut filler tobacco may comprise types of
tobacco such as Virginia, Burley, Oriental and Semi Oriental. The
tobacco cut filler may comprise a blend of two or more different
types of tobacco; e.g. of the above-mentioned types of tobacco.
Alternatively, the tobacco cut filler may comprise a single one of
the above-mentioned types of tobacco. The tobacco cut filler may
comprise tobaccos that are, for example, air, sun or flue-cured.
Alternatively or in addition, the tobacco cut filler may have
undergone treatment, for example, to reduce tobacco-specific
nitrosamines (TSNA). Besides tobacco leaf, the tobacco cut filler
may include other ingredients typically found in tobacco cut filler
such as, for example, expanded tobacco, homogenized tobacco (e.g.
reconstituted tobacco, cast tobacco, or extruded tobacco), tobacco
stem (e.g. expanded or improved stem), tobacco fines, and any
combinations thereof. Flavours and casings comprising one or more
humectants, flavourants, sugars or combinations thereof may also be
applied to the tobacco cut filler in a known manner.
[0035] The rod element 11 is substantially cylindrical in shape,
with smokeable material circumscribed by an outer wrapper of
smokeable cigarette paper. The filter element 1 is also cylindrical
in shape with a cross-section substantially matching that of the
rod element 11. The filter element 1 contains filter plugs 4, 6
comprising filtration material to filter the mainstream smoke as it
passes between the first 2 and second ends 3. Examples of suitable
filtration material include cellulose acetate, paper and
combinations thereof. The filter element may have at least one
filter segment comprised of a fibrous filtration material, and
optionally multiple segments comprised of a fibrous filtration
material, typically a cellulosic filtration material, such as
cellulose acetate tow.
[0036] The filter element 1 itself typically has a length in the
range of about 5 mm to 40 mm, preferably in the range of about 15
mm to about 30 mm.
[0037] The liquid-filled capsule 7 is positioned within the filter
element 1 between the first 2 and second 3 ends. The capsule 7
comprises an outer shell containing a liquid L, which may include
one or more flavourings. The shell of the capsule 7 is configured
to break under a user-applied force F to release the liquid L. The
shell may be made from a resiliently deformable material, such as a
polymer material. The liquid in the capsule may comprise purified
water or a water-based liquid which contains a dissolved or
suspended substance, such as a flavouring substance.
[0038] The capsule 7 is configured such that a force applied to the
outer side of the filter with the user's fingers, for example in an
inward radial direction as shown in FIG. 3, is sufficient to break
the capsule 7 and release a substantial amount of the liquid L
contained therein. The liquid-filled capsule 7 depicted in FIG. 3
is a directional capsule 7 configured to release the liquid in a
predetermined direction, as will be described in further detail
with reference to FIG. 2.
[0039] In the presently described embodiment the capsule 7 has a
partially trapezoidal shape. In other embodiments the capsule 7 may
be elongate. Alternatively, the capsule 7 may be substantially
spherical, or ovoidal. The capsule 7 may be a seamless shell.
Alternatively, the capsule 7 may be an open-ended shell, which is
closed and sealed with a cap. The shell may have a side wall or
lateral wall that extends from an end wall to an open end and thus
surrounds or defines a cavity in the shell. The lateral wall may
end in a rim at the open end to facilitate application of the cap.
The lateral wall may be generally cylindrical or may be faceted.
The side or lateral wall may taper or narrow from the open end
towards the end wall. The cap is typically formed and cut from a
section or an expanse of sheet material, such as a laminated
plastic sheet material.
[0040] The liquid capsule 7 may contain a liquid volume of at least
0.05 ml. By providing this volume of liquid, the quantity of liquid
released with one compression is sufficient to produce an effect on
the characteristics of the mainstream smoke. This is a relatively
high liquid volume in comparison to liquid capsules that have been
used previously. The breakage of the liquid capsule 7 therefore
causes significant wetting within the smoking article 1, which can
extend within the filter element 1 and also within part of the rod
element 11. The tipping wrapper 12 can also become wet. In the
presently described embodiment the tipping wrapper 12 has a wet
tensile strength of at least 0.15 kN/m. It has been determined that
this property of the tipping wrapper 12 provides sufficient
robustness under normal use to prevent detachment of the rod
element 11 from the filter element 1 even after the liquid L has
been released.
[0041] The first, connection end 2 of the filter element abuts an
end of the rod element 11 and the connection is secured via the
circumferential wrapping of the tipping wrapper 12 which surrounds
at least the join between the rod 11 and filter 1 elements. The
tipping wrapper 12 extends over the connection in both opposing
axial directions and is attached to the outer surface of the rod 11
and filter 1 elements, for example via an adhesive. The length that
the attached tipping wrapper 12 extends either side of the
connection may be varied with a greater extension enhancing the
strength of the connection between the filter 1 and rod 11 but also
having implications on the characteristics of the inhaled smoke if
it extends too far along the tobacco rod such that it is burned
during use.
[0042] Typically, the tipping wrapper 12 is generally rectangular
and is wrapped cylindrically around at least part of the rod
element 11 of smokeable material and at least part of the filter
element 1, as can be seen in FIG. 4. The tipping wrapper 12 is
wrapped around and thereby encompasses or envelops at least part of
the filter element 1 so that the tipping wrapper 12 physically and
mechanically attaches or connects the filter element 1 to the rod
element 11 of smokeable material. In this way, the tipping wrapper
12 will typically encompass or circumscribe the filter element 1
and an adjacent end portion of the rod element 11 of smokeable
material. Thus, the portion of the rod element 11 of smokeable
material encompassed or circumscribed by the tipping wrapper 12 is
typically in the range of 1 mm to 16 mm in length, for example in
the range of 2 mm to 12 mm in length. As used herein, the term
"length" denotes the dimension in the axial or longitudinal
direction of the smoking article 10.
[0043] The tipping wrapper 12 may include a bonding region in which
an adhesive is applied. That is, the tipping wrapper 12 is
typically bonded in a region in which the tipping wrapper 12
overlaps with itself when wrapped around the filter element 1 and
at least part of the rod element 11 of smokeable material. The
bonding region is preferably elongate and extends in a longitudinal
direction of the smoking article 10; for example, along an edge
portion of the tipping wrapper 12.
[0044] As discussed, the tipping wrapper 12 has a wet tensile
strength of at least 0.15 kN/m. In some embodiments the tipping
wrapper 12 has a wet tensile strength of at least 0.25 kN/m, for
example of about 0.35 kN/m. The tipping wrapper 12 has a wet
tensile strength of less than about 0.55 kN/m.
[0045] The tipping wrapper 12 has a dry tensile strength of at
least about 1 kN/m, for example of at least about 1.25 kN/m, such
as of at least about 1.5 kN/m. The tipping wrapper 12 has a dry
tensile strength of less than about 5 kN/m, for example of no more
than 3 kN/m.
[0046] The tipping wrapper 12 has a dry to wet tensile strength
ratio of no more than 15, for example 12 or less, 9 or less or,
most preferably 6 or less. Tests have indicated that a range of 5
to 7 for the dry to wet tensile strength ratio is achievable and
provides a beneficial effect in maintaining the strength of the
tipping wrapper as it transitions from a dry to wet state.
[0047] In use, a force is applied by the user to the outer surface
of the filter element 1 in a direction indicated by arrows F in
order to break the capsule and release the liquid L. This force is
typically provided by the opposing pressure of the fingers of the
user in a direction perpendicular to the elongate axis of the
smoking article 10 as indicated by arrows F. Under this pressure
the filter element 1 deforms inwardly, producing a corresponding
force on the capsule 7 such that the shell deforms with the
increasing internal pressure resulting in rupture and expulsion of
the liquid L.
[0048] The liquid L is expelled from the capsule 7 and disperses
within the filtration material 6, 4. A portion of the released
liquid L may also travel towards the tipping wrapper 12 and may
reach and be absorbed by the tipping wrapper 12. In embodiments
where the filter element 1 is wrapped by a filter wrapper 8 (FIG.
4), typically when the filter element 1 comprises more than one
segment, the tipping wrapper 12 is attached to the filter element 1
by applying adhesive onto the filter wrapper 8. However,
application of adhesive is generally only along a line parallel to
the longitudinal axis of the filter element 1 and there is a gap
between the filter wrapper 8 and the tipping wrapper 12 through
which the released liquid L can rapidly advance by capillary
action, once it soaks the filter wrapper 8 and leaks through it and
into this region. When the liquid is released towards the first
filter end 2, or tobacco end, the liquid advances towards the
tobacco rod 11 and may reach and be absorbed by the region of
tipping wrapper 12 that connects the tobacco rod 11 to the filter
element 1, which is the weakest region of the smoking article
10.
[0049] The smoking article 10 is ignited at the opposite end of the
tobacco rod 11 to the filter 1 and the resultant smoke travels
through the tobacco rod 11 and filter element 1, passing through
the dispersed liquid L where it affects the characteristics of the
mainstream smoke before being inhaled by the user at the second end
of the filter 3. In normal use, the user typically taps the
mouthpiece 1 to dislodge spent ash. The wet tensile strength of the
tipping wrapper 12 is selected to provide sufficient strength such
that the smoking article may resist damage that may otherwise
occur, such as detaching of the rod 11 from the filter 1, even if
liquid reaches and is absorbed by the tipping wrapper 12 at the
region where it connects the tobacco rod 11 to the filter element
1.
[0050] The liquid-filled capsule 7 is a directional capsule which
is configured to release liquid L in a predetermined direction via
the provision of a known rupture region P. For example, the shell
of the capsule 7 is configured such that it has a weak point or
region P which gives way preferentially on the application of a
force F such that the contained liquid L is ejected from this known
point or region. The weakened region may comprise one or more lines
of weakness. Alternatively, the weakened region may comprise one or
more stress concentrator elements. A combination of lines of
weakness and stress concentrator elements would also be possible to
form the weakened region.
[0051] The rupture region of the directional capsule 7 may be
arranged such that the liquid L is released in an axial direction,
such as a longitudinal axis of the filter element 1, into an
adjacent region of the filtration material. The shell of the
directional capsule 7 and the rupture region P may be configured
such that the user applied force causes expulsion or jetting of the
liquid L in the predetermined direction. The jetting of the liquid
L may increase the speed with which liquid L reaches the tipping
wrapper 12. The jetting may also increase the amount of liquid L
which reaches the tipping wrapper 12, especially a localised region
of the tipping wrapper 12, such as a tobacco to filter connection
region. These factors increase the importance of having a tipping
wrapper 12 with a high wet tensile strength, which is greater than
0.15 kN/m.
[0052] In the presently described embodiment, the rupture region P
of the directional capsule 7 faces the first, connection end 2 of
the filter element 1. In this way, the released liquid L is
dispersed adjacent to the first end 2 of the filter element 1.
Although this area of the smoking article 10, near the connection
point of the rod 11 and filter 1 elements, is known to be a weak
point (particularly following wetting), the strengthening provided
by the defined tipping wrapper 12 is such that the risk of snapping
is mitigated. The desired effects on the characteristics of the
mainstream smoke are therefore obtained without increased risk of
damage to the smoking article 10.
[0053] The distance D between the rupture region P of the capsule 7
and the first end of the filter element 1 may also be adjusted such
that the ejected liquid L is positioned at an optimum location.
Testing has shown that a distance of at least 7 mm, preferably at
least 9 mm, provides an optimum dispersion of the liquid L without
projecting the expelled liquid too far into the tobacco rod 11.
[0054] The filter element 1 may further comprise a plurality of
filter segments arranged in series along a longitudinal axis of the
filter element 1. In the example of FIGS. 2 and 3, the filter
element 1 comprises three filter segments 4, 5, 6. The directional
capsule 7 is provided in the central filter segment 5, with a
filter segment containing a filter plug positioned on both the
upstream 6 and downstream 4 sides. The filter segments are
connected by a filter wrapper 8 (shown in FIG. 4), which is
circumferentially wrapped around the filter segments 4, 5, 6 to
secure them together.
[0055] In other embodiments one or more filter segments may be
individually wrapped and some or all of the filter segments may be
combined by a combiner filter wrapper 8.
[0056] In some embodiments at least one filter segment may contain
a particulate material, such as a sorbent or flavouring. The
particulate material may be embedded in fibrous filtration material
or contained in a cavity. The particulate material may be arranged
between the rupture region P of the directional capsule 7 and the
first end 2 of the filter element 1, or between the second end 3 of
the filter element 3 and the directional capsule 7. Selection will
depend on the desired effect on the characteristics of the
mainstream smoke through the filter element 1.
[0057] In other embodiments the filter element 1 comprises a single
filter segment within which the liquid capsule 7 is arranged.
[0058] Although in the embodiment of FIGS. 2 and 3, the directional
capsule 7 is arranged such that the rupture region P is located
closer to the first end 2 of the filter element 1, in alternative
embodiments the directional capsule 7 may be arranged in the filter
element 1 with the rupture region P located closer to the second
end 3 of the filter element than to the first end 2 of the filter
element 1.
[0059] Although in the described embodiment, one capsule 7 is
provided in the filter element 1, in alternative embodiments the
filter element 1 may comprise more than one capsule 7, for example
one or more directional capsules 7 and one or more non-directional
capsules. Where one or more directional capsules 7 are provided,
all of the directional capsules 7 may be oriented in the same
direction; alternatively, one or more directional capsules may be
oriented in a first direction (with their respective rupture point
P pointing towards the end 2 for connection to the rod element 11
of smokeable material, i.e. the first end 2 of the filter element
1) and one or more capsules 7 may be oriented in a second direction
(with their respective rupture region P pointing towards the end
for insertion into the mouth of the user, i.e. the second end 3 of
the filter element 1).
[0060] The above described embodiments refer to a directional
capsule 7. In other embodiments a non-directional capsule may be
used. The capsule may for example be an isotropic capsule such as a
conventional spherical capsule.
[0061] FIG. 4 shows a preferred way of connecting the tobacco rod
11 to the filter element 1 with the tipping wrapper 12. The tipping
wrapper 12 is pulled in the machine direction (MD) from a reel of
tipping wrapper material (FIG. 1) and wrapped about the filter
element 1 such that the cross direction (CD) of the tipping wrapper
material is substantially parallel to the longitudinal axis of the
filter element 1. As a result, the tipping wrapper 12 is wrapped
about the filter element 1 and the tobacco rod 11 so that the cross
direction (CD) is substantially parallel to the longitudinal axis
of the filter element 1.
[0062] Alternatively, the tipping wrapper 12 may be wrapped about
the filter element 1 such that the machine direction (MD) of the
tipping wrapper material is substantially parallel to the
longitudinal axis of the filter element 1. As a result, the tipping
wrapper 12 is wrapped about the filter element 1 and the tobacco
rod 11 so that the machine direction (MD) is substantially parallel
to the longitudinal axis of the filter element 1.
* * * * *