U.S. patent application number 14/402482 was filed with the patent office on 2015-06-04 for blended rods for use in aerosol-generating articles.
This patent application is currently assigned to Philip Morris Products S.A.. The applicant listed for this patent is Philip Morris Products S.A.. Invention is credited to John Faulkner, Pierre-Yves Gindrat, Alessandro Metrangolo, Jean-Pierre Schaller, Jean-Claude Schneider.
Application Number | 20150150302 14/402482 |
Document ID | / |
Family ID | 48539170 |
Filed Date | 2015-06-04 |
United States Patent
Application |
20150150302 |
Kind Code |
A1 |
Metrangolo; Alessandro ; et
al. |
June 4, 2015 |
BLENDED RODS FOR USE IN AEROSOL-GENERATING ARTICLES
Abstract
A rod for an aerosol-generating article is provided, including
at least two sheets of tobacco material gathered together and
circumscribed by a wrapper. The rod includes a first sheet of a
first tobacco material and a second sheet of a second tobacco
material. The second sheet of the second tobacco material is
physically or chemically different to the first sheet of the first
tobacco material.
Inventors: |
Metrangolo; Alessandro;
(Neuchatel, CH) ; Gindrat; Pierre-Yves; (Saxon,
CH) ; Faulkner; John; (Gorgier, CH) ;
Schaller; Jean-Pierre; (Geneve, CH) ; Schneider;
Jean-Claude; (Auvernier, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Philip Morris Products S.A. |
Neuchatel |
|
CH |
|
|
Assignee: |
Philip Morris Products S.A.
Neuchatel
CH
|
Family ID: |
48539170 |
Appl. No.: |
14/402482 |
Filed: |
May 30, 2013 |
PCT Filed: |
May 30, 2013 |
PCT NO: |
PCT/EP2013/061208 |
371 Date: |
November 20, 2014 |
Current U.S.
Class: |
131/77 ; 131/230;
131/329; 131/352 |
Current CPC
Class: |
A24F 47/004 20130101;
A24B 13/00 20130101; A24B 15/14 20130101; A24B 3/14 20130101; A24C
5/18 20130101 |
International
Class: |
A24B 13/00 20060101
A24B013/00; A24C 5/18 20060101 A24C005/18; A24F 47/00 20060101
A24F047/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2012 |
EP |
12170356.5 |
Claims
1. A rod comprising a first sheet of a first tobacco material and a
second sheet formed of a second tobacco material gathered together
with the first sheet of the first tobacco material and
circumscribed by a wrapper, in which both the first tobacco
material and the second tobacco material are homogenised tobacco
material, the second tobacco material being chemically different to
the first tobacco material.
2. The rod according to claim 1 in which both the first and second
tobacco materials comprise an aerosol-former, the proportion by
weight of aerosol-former in the first tobacco material being
different to the proportion by weight of aerosol-former in the
second tobacco material.
3. The rod according to claim 1 in which the first tobacco material
comprises a first aerosol-former and the second tobacco material
comprises a second aerosol-former different to the first
aerosol-former.
4.-5. (canceled)
6. The rod according to claim in which at least one of the first
and second sheets of tobacco material is crimped.
7.-9. (canceled)
10. The rod according to claim 1 comprising a further continuous
sheet of a third tobacco material.
11. An aerosol-generating article, for example a smoking article,
comprising a rod according to claim 1.
12. An aerosol-forming substrate for a heated aerosol-generating
article, comprising a rod according to claim 1.
13. An aerosol-generating article comprising a combustible heat
source and an aerosol-forming substrate according to claim 12
located downstream of the combustible heat source.
14. An aerosol-generating article for use in an
electrically-operated aerosol-generating system comprising an
aerosol-forming substrate according to claim 12.
15. A system comprising an electrically-operated aerosol-generating
apparatus and an aerosol-generating article for use with the
apparatus, the aerosol-generating article comprising an
aerosol-forming substrate according to claim 12.
16. A method of forming a rod, comprising: providing a first
continuous sheet of a first tobacco material; providing a further
continuous sheet of a second tobacco material; simultaneously
gathering together the first continuous sheet and the further
continuous sheet; circumscribing the gathered first and second
tobacco materials with a wrapper to form a continuous rod; and
severing the continuous rod into a plurality of discrete rods, in
which both the first tobacco material and the second tobacco
material are homogenised tobacco material, the first tobacco
material being chemically different to the second tobacco
material.
17. The method according to claim 16 in which at least the first
continuous sheet of the first tobacco material is crimped prior to
being gathered.
18.-19. (canceled)
20. The method according to claim 16 in which both the first sheet
and the further sheet are crimped prior to being gathered.
Description
[0001] The present specification relates to rods comprising two or
more sheets of tobacco material gathered together to form a rod for
use in aerosol-generating articles. The specification also relates
to aerosol-generating articles comprising such rods, and methods
for forming such rods.
[0002] Processes and apparatus for producing shreds, strands or
strips of tobacco material are known in the art. Typically, the
width of such shreds, strands and strips of tobacco material is
about 3 mm or less.
[0003] For example, U.S. Pat. No. 4,000,748 discloses a process and
apparatus for shredding a sheet of reconstituted tobacco into
strips and crimping the resultant strips in a substantially
simultaneous operation. The sheet of tobacco material is moved
between a pair of rotating and intermeshing stacks of disks which
shred the sheet into a plurality of strips about 0.65 to 1.55 mm in
width. The forward motion of the resultant strips is retarded by
engagement with facing surfaces of neighbouring disks causing a
buckling of the strips into a crimped configuration. The crimped
strips are reported to provide an increase in fill value.
[0004] The formation of rods for aerosol-generating articles
comprising crimped or uncrimped shreds of tobacco material suffers
from a number of disadvantages including those discussed below.
[0005] Firstly, shredding tobacco material undesirably generates
tobacco fines and other waste.
[0006] Secondly, rods comprising shreds of tobacco material exhibit
`loose ends`. That is, there is a loss of shreds of tobacco
material from the ends of the rod. This is exacerbated by breakage
of the shreds of tobacco material during rod formation. Loose ends
are not only aesthetically undesirable, but can also
disadvantageously lead to the need for more frequent cleaning of
manufacturing equipment and aerosol-generating devices. The problem
of loose ends is particularly exacerbated in aerosol-generating
articles, because the rod length of aerosol-generating substrate
tends to be low in comparison with conventional cigarettes, and
therefore the proportion of substrate material that is in proximity
to an end is greater.
[0007] Thirdly, rods comprising shreds of tobacco material exhibit
high weight standard deviations. That is, rods of the same
dimensions tend to be of inconsistent weight. This is due in part
to the tendency of the rods to exhibit loose ends as mentioned
above. The high weight standard deviation of rods comprising shreds
of tobacco material leads to an undesirably high rejection rate of
rods whose weight falls outside of a selected acceptance range.
Furthermore, rods comprising shreds of tobacco material exhibit
non-uniform densities. That is, the density along the rod length of
the rod tends to be inconsistent. This is due to variations in the
quantity of tobacco material at different locations along the rod,
which results in `voids`, which are regions having reduced
quantities of tobacco material, and `pads`, which are regions
having increased levels of tobacco material. The non-uniform
density of rods comprising shreds of tobacco material can
undesirably affect the resistance to draw (RTD) of the rods. In
addition, the non-uniform density of rods comprising shreds of
tobacco material can lead to loose ends when a void is located at
the end of the rod.
[0008] Loose ends, high weight standard deviations and non-uniform
densities as exhibited by rods comprising shreds of tobacco
material are particularly problematic and undesirable in rods of
short rod length. Rods of short rod length are sometimes referred
to as plugs.
[0009] There are many types of tobacco and many ways in which two
tobacco types may differ. For example, different types of tobacco
may derive from different tobacco plant varieties, or from
different portions of a tobacco plant. Tobaccos may differ if they
have been processed in different ways in order to vary certain
characteristics. Tobaccos may differ if they comprise different
additives, or different proportions of additives.
[0010] Aerosol-generating articles, such as traditional lit-end
cigarettes, typically comprise blended tobacco. Blended tobacco
typically comprises shreds and strips of many different types of
tobacco leaf and homogenised tobacco. Properties of the cigarette
such as flavour or perceived harshness may be controlled by
blending many different types of tobacco.
[0011] EP-A1-2 062 484 discloses a process for forming smokeless
tobacco articles for oral consumption. A sheet of reconstituted
tobacco is gathered into a rod, wrapped, and cut into pieces
suitable for oral consumption.
[0012] It would be desirable to provide rods comprising tobacco
material for use in aerosol-generating articles.
[0013] A rod may be provided comprising a first sheet of tobacco
material and at least one continuous element of tobacco material
gathered together with the first sheet of tobacco material and
circumscribed by a wrapper, the rod including a first sheet of a
first tobacco material and a continuous element of a second tobacco
material, the second tobacco material being chemically different to
the first tobacco material. The continuous element may comprise a
different blend of tobacco or a different type of tobacco compared
to the first sheet. The continuous element may comprise a different
aerosol-former compared to the first sheet. The continuous element
may comprise a different proportion of aerosol-former compared to
the first sheet. A continuous element of tobacco material may be in
the form of a ribbon, strip, yarn, tape, filament, thread, or other
elongate element. The continuous element of tobacco material may be
a second sheet of tobacco material.
[0014] A rod may be provided comprising at least two sheets of
tobacco material gathered together and circumscribed by a wrapper,
the rod including a first sheet of a first tobacco material and a
second sheet of a second tobacco material, the second sheet of the
second tobacco material being physically or chemically different to
the first sheet of the first tobacco material.
[0015] By way of non-limiting examples, the two sheets may be
physically different if they have different physical dimensions,
different surface textures, different morphologies, different
densities, or different porosities. Sheets may be textured by
crimping and the crimping of one sheet may be of a different degree
to the crimping of the other sheet. For example, one sheet may have
a different depth of crimping compared to the other sheet or one
sheet may have a different density of crimping, i.e. a different
number of crimp lines per unit distance, compared to the other
sheet. The skilled person will be aware of other physical
differences that may characterise the two sheets of tobacco
material.
[0016] By way of non-limiting examples, the two sheets may be
chemically different if they contain different chemical
constituents, for example if the two sheets contain different
tobacco blends, or different types of aerosol former, or different
types of plasticiser, or different flavourants, or different
proportions of any element. For example, one sheet may comprise a
different proportion of Virginia tobacco compared with the other
sheet, or one sheet may comprise a different proportion of an
aerosol former such as glycerine compared to the other sheet.
[0017] Once the first sheet and the second sheet have been gathered
into a rod they may be described as gathered sheets. The gathered
sheets of material preferably extend along substantially the entire
rod length of the rod and across substantially the entire
transverse cross-sectional area of the rod.
[0018] The tobacco material forming the at least two sheets is
preferably reconstituted tobacco or homogenised tobacco. The
tobacco material may comprise an aerosol-former.
[0019] As used herein, the term `rod` is used to denote a generally
cylindrical element of substantially circular, oval or elliptical
cross-section.
[0020] As used herein, the term `sheet` denotes a laminar element
having a width and length substantially greater than the thickness
thereof. The width of a sheet is greater than 10 mm, preferably
greater than 20 mm or 30 mm.
[0021] As used herein, the term `rod length` denotes the dimension
in the direction of the cylindrical axis of rods as described
herein.
[0022] As used herein, the term `homogenised tobacco` denotes a
material formed by agglomerating particulate tobacco.
[0023] As used herein, the term `gathered` denotes that the sheet
of tobacco material is convoluted, folded, or otherwise compressed
or constricted substantially transversely to the cylindrical axis
of the rod.
[0024] As used herein, the terms `upstream` and `downstream` are
used to describe the relative positions of components, or portions
of components, of aerosol-generating articles comprising rods as
described herein in relation to the direction of air drawn through
the aerosol-generating articles during use thereof.
[0025] The inclusion of gathered sheets of homogenised tobacco
material in rods as described herein advantageously significantly
reduces the risk of loose ends compared to rods comprising shreds
of tobacco material.
[0026] Rods comprising at least two sheets of tobacco material
advantageously exhibit significantly lower weight standard
deviations than rods comprising shreds of tobacco material. The
weight of a rod of a particular rod length is determined by the
density, width and thickness of the sheets of tobacco material that
are gathered to form the rod. The weight of rods of a particular
rod length can thus be regulated by controlling the density and
dimensions of the individual sheets of tobacco material. This
reduces inconsistencies in weight between rods of the same
dimensions, and so results in lower rejection rate of rods whose
weight falls outside of a selected acceptance range.
[0027] Rods comprising sheets of tobacco material as described
herein advantageously exhibit more uniform densities than rods
comprising shreds of tobacco material.
[0028] Tobacco sheet material such as homogenised tobacco sheet
material may be produced using different types of tobacco. For
example, tobacco sheet material may be formed using tobaccos from a
number of different varieties of tobacco, or tobacco from different
regions of the tobacco plant, such as leaves or stem. After
processing, the sheet has consistent properties and a homogenised
flavour. A single sheet of homogenised tobacco material may be
produced to have a specific flavour. To produce a product having a
different flavour, a different tobacco sheet material needs to be
produced. Some flavours that are produced by blending a large
number of different shredded tobaccos in a conventional cigarette
may be difficult to replicate in a single homogenised tobacco
sheet. For example, Virginia tobaccos and Burley tobaccos may need
to be processed in different ways to optimise their individual
flavours. It may not be possible to replicate a particular blend of
Virginia and Burley tobaccos in a single sheet of homogenised
tobacco material.
[0029] A rod may be provided comprising a sheet of a first tobacco
material and a sheet of a second tobacco material that is
chemically different from the first tobacco material. The sheets of
tobacco material are gathered together to form the rod. By
combining two different sheets of tobacco material in a single rod,
new blends may be created that could not be produced by a single
sheet of homogenised tobacco. This concept may be illustrated by
the following non-limiting examples.
[0030] The first tobacco material may be dominated by Virginia
tobacco and the second tobacco material may be dominated by Burley
tobacco.
[0031] The first tobacco material may be dominated by Virginia
tobacco and the second tobacco material may be dominated by
Oriental tobacco.
[0032] The first tobacco material may be dominated by Virginia
tobacco and the second tobacco material may comprise Perique
tobacco.
[0033] The first tobacco material may be formed primarily from leaf
tobacco and the second tobacco material may be derived primarily
from stem tobacco.
[0034] The first tobacco material may be treated or aged or
processed or cured in a different way from the second tobacco
material such that it is chemically different. Homogenised tobacco
may comprise aerosol forming compounds such as glycerine and
propylene glycol. This may be particularly advantageous when the
homogenised tobacco is to be used as an aerosol-forming substrate
of a heated aerosol-forming article.
[0035] The first tobacco material may comprise a first
aerosol-forming compound and the second tobacco material may
comprise a second aerosol-forming compound different to the first
aerosol-forming compound. For example, it may be preferable to used
glycerine as an aerosol-forming compound of a first sheet of
tobacco material and triethylene glycol as an aerosol-forming
compound of a second sheet of tobacco material.
[0036] A rod as described herein may be heated to evolve volatile
compounds, which condense to form an inhalable aerosol. The
temperature at which an aerosol forms and the rate at which the rod
is consumed may depend to some degree on the nature of the
aerosol-forming compounds present in the rod. It may be desirable
to modify or improve a consumer experience by controlling the
temperature and rate at which aerosol is evolved. It may be
desirable that a rod comprises two different sheets of tobacco
material that each provide a different aerosol evolution response
to a heating profile.
[0037] The first tobacco material may comprise a different amount
of aerosol-forming compound to the second tobacco material. For
example, the first tobacco material may comprise 5% by weight
glycerine, while the second tobacco material may comprise 10% by
weight glycerine.
[0038] The first tobacco material may comprise aerosol-forming
compounds that form an aerosol at a lower temperature than
aerosol-forming compounds of the second tobacco material.
[0039] Homogenised tobacco materials may include various other
additives such as humectants, plasticisers, flavourants, fillers,
binders and solvents. Some additives may be more suitable for use
with one type of tobacco material than another type of tobacco
material.
[0040] The first tobacco material may comprise different additives
to the second tobacco material.
[0041] The first tobacco material may comprise a different
proportion of additives compared to the second tobacco
material.
[0042] A rod may be provided comprising a first sheet of a first
tobacco material and a second sheet of a second tobacco material
that is physically or morphologically different from the first
sheet. One of the sheets of tobacco material may be a textured
sheet of material. Use of at least one textured sheet of material
may advantageously facilitate gathering of the sheets to form a
rod. Both or all of the sheets of tobacco material in a rod may be
textured sheets of material.
[0043] As used herein, the term `textured sheet` denotes a sheet
that has been crimped, embossed, debossed, perforated or otherwise
deformed. Crimping is a preferred form of texturing. Textured
sheets of material may comprise a plurality of spaced-apart
indentations, protrusions, perforations or a combination
thereof.
[0044] The first sheet may be a textured sheet of tobacco material
and the second sheet may be non-textured.
[0045] Both first and second sheets may be textured sheets of
tobacco material.
[0046] The first sheet may be a textured sheet of tobacco material
that is textured in a different way to the second sheet of tobacco
material. For example, the first sheet may be crimped and the
second sheet may be perforated.
[0047] Both first and second sheets may be crimped sheets that are
morphologically different from each other. For example, the second
sheet may be crimped with a different number of crimps per unit
width of sheet compared to the first sheet.
[0048] By gathering together at least two sheets of tobacco
material having different textures the physical properties of the
rod may be controlled. For example, the density of the rod may be
controlled by gathering at least two sheets of tobacco material
that are differently textured.
[0049] As used herein, the term `crimped sheet` is intended to be
synonymous with the term `creped sheet` and denotes a sheet having
a plurality of substantially parallel ridges or corrugations.
Preferably, a crimped sheet of tobacco material, for example a
crimped sheet of homogenised tobacco material, has a plurality of
ridges or corrugations substantially parallel to the cylindrical
axis of the rod. This advantageously facilitates gathering of the
crimped sheet of tobacco material to form the rod. However, it will
be appreciated that crimped sheets of tobacco material for use in
rods as described herein may alternatively or in addition have a
plurality of substantially parallel ridges or corrugations disposed
at an acute or obtuse angle to the cylindrical axis of the rod.
[0050] In certain embodiments, sheets of material for use in rods
as described herein may be substantially evenly textured over
substantially their entire surface. For example, crimped sheets of
material for use in rods as described herein may comprise a
plurality of substantially parallel ridges or corrugations that are
substantially evenly spaced-apart across the width of the
sheet.
[0051] The at least two sheets that are gathered together to form
the rod may have different physical dimensions. The sheets are
effectively endless sheets, and are supplied as a web to the
manufacturing process. The width and thickness of the sheets may be
varied, however.
[0052] It may be desirable to gather together two sheets each
having a different thickness or each having a different width. This
may alter the physical properties of the rod. This may facilitate
the formation of a blended tobacco rod from sheets of tobacco
material of different chemical composition.
[0053] The first sheet may have a first thickness and the second
sheet may have a second thickness that is a percentage or a
fraction of the first thickness, for example a half or a third or a
quarter of the first thickness.
[0054] The first sheet may have a first width and the second sheet
may have a second width that is different to the first width.
[0055] The first sheet of the first tobacco material and the second
sheet of the second tobacco material may be disposed in overlapping
relationship prior to being gathered together, or at the point at
which they are gathered together. The sheets may have the same
width and thickness.
[0056] The sheets may have different thicknesses. The sheets may
have different widths. The sheets may be differently textured.
[0057] Where it is desired that the first sheet and the second
sheet are both textured, the sheets may be simultaneously textured
prior to being gathered. For example, the sheets may be brought
into overlapping relationship and passed through a texturing means,
such as a pair of crimping rollers.
[0058] Alternatively, each sheet may be separately textured and
then subsequently brought together to be gathered into a rod. For
example, where the two sheets have a different thickness, it may be
desirable to crimp the first sheet in a different way to the second
sheet.
[0059] A rod may comprise one or more additional sheets of material
gathered together with the first and second sheets to form the rod.
Any additional sheet or sheets may be textured, for example
crimped, prior to being gathered. Any additional sheet or sheets
may comprise additional aerosol-forming materials, such as one or
more additional sheets of homogenised tobacco.
[0060] A rod as described herein may be used as an aerosol-forming
substrate in an aerosol-generating article.
[0061] An aerosol generating article may be provided comprising a
rod as described herein.
[0062] Rods as described herein may be used as rods of combustible
smokable material in lit-end smoking articles. In one embodiment,
rods as described herein may be used as rods of combustible
smokable material in lit-end cigarettes comprising a rod of
combustible smokable material and a filter downstream of the rod of
combustible smokable material.
[0063] In one embodiment, rods as described herein may be
particularly beneficial as a component of a heated
aerosol-generating article, for example as an aerosol-forming
substrate of a heated aerosol-generating article.
[0064] Heated aerosol-generating systems operate by heating an
aerosol-forming substrate to generate an aerosol from the material
of the substrate. The aerosol can then be inhaled by a
consumer.
[0065] A number of aerosol-generating articles in which an
aerosol-forming substrate is heated rather than combusted have been
proposed in the art. Typically in heated aerosol-generating
articles, an aerosol is generated by the transfer of heat from a
heat source, for example a chemical, electrical or combustible heat
source, to a physically separate aerosol-forming substrate, which
may be located within, around or downstream of the heat source.
[0066] As used herein, the term `aerosol-forming substrate` denotes
a substrate consisting of or comprising an aerosol-forming material
that is capable of releasing volatile compounds upon heating to
generate an aerosol. A sheet of tobacco material is an
aerosol-forming substrate for the purposes of this
specification.
[0067] Rods as described herein are particularly suited for use as
aerosol-forming substrates of heated aerosol-generating articles.
Aerosol-forming substrates in heated aerosol-generating articles
are typically significantly shorter in rod length than rods of
combustible smokable material in conventional lit-end smoking
articles. As noted above, loose ends, high weight standard
deviations and non-uniform densities as exhibited by rods
comprising shreds of tobacco material are particularly undesirable
in rods of aerosol-generating material having a short rod length.
Use of short rods as described herein as aerosol-generating
substrates in heated aerosol-generating articles advantageously
minimises or avoids one or more of the disadvantages associated
with the use of short rods comprising shreds of tobacco material
previously discussed above.
[0068] In one embodiment, rods as described herein may be used as
aerosol-forming substrates in heated aerosol-generating articles
comprising a combustible heat source and an aerosol-generating
substrate downstream of the combustible heat source.
[0069] For example, rods as described herein may be used as
aerosol-generating substrates in heated aerosol-generating articles
of the type disclosed in WO-A-2009/022232, which comprise a
combustible carbon-based heat source, an aerosol-generating
substrate downstream of the combustible heat source, and a
heat-conducting element around and in contact with a rear portion
of the combustible carbon-based heat source and an adjacent front
portion of the aerosol-generating substrate. However, it will be
appreciated that rods as described herein may also be used as
aerosol-generating substrates in heated aerosol-generating articles
comprising combustible heat sources having other constructions.
[0070] In another embodiment, rods as described herein may be used
as aerosol-generating substrates in heated aerosol-generating
articles for use in electrically-operated aerosol-generating
systems in which the aerosol-generating substrate of the heated
aerosol-generating article is heated by an electrical heat
source.
[0071] For example, rods as described herein may be used as
aerosol-generating substrates in heated aerosol-generating articles
of the type disclosed in EP-A-0 822 670.
[0072] A system may be provided comprising an electrically-operated
aerosol-generating apparatus and an aerosol-generating article for
use with the apparatus. The aerosol-generating article comprises a
rod or an aerosol-forming substrate as described herein.
[0073] The insertion and removal of heated aerosol-generating
articles from an electrically-operated aerosol-generating system,
for example an electrically-heated aerosol-generating system, where
those articles include a rod comprising shreds of tobacco material,
tends to dislodge shreds of tobacco material from the rod. This can
disadvantageously result in the need for more frequent cleaning of
the electrical heat source and other parts of the
electrically-operated aerosol-generating system in order to remove
the dislodged shreds.
[0074] In contrast, insertion and removal of heated
aerosol-generating articles including an aerosol-generating
substrate comprising a rod as described herein is less likely to
result in dislodgement of tobacco material.
[0075] A filter for an aerosol-generating article may be provided,
wherein the filter comprises a rod as described herein. Rods may be
used in filters for both lit-end aerosol-generating articles, such
as conventional smoking articles, and heated aerosol-generating
articles. Rods as described herein may used in filters comprising a
single filter segment. Rods as described herein may also be used in
multi-component filters comprising two or more filter segments.
[0076] Filters comprising tobacco-containing filter segments are
known in the art. For example, EP-A-1 889 550 discloses a
multi-component filter for a smoking article comprising: a mouth
end segment; a first flavour release segment comprising tobacco or
other plant leaf upstream of the mouth end segment; and a second
flavour release segment comprising filtration material and a
flavourant upstream of the first flavour release segment. The
resistance to draw of the second flavour release segment is greater
than the resistance to draw of the first flavour release segment
and the resistance to draw of the second flavour release segment is
greater than the resistance to draw of mouth end segment.
[0077] In certain embodiments, rods as described herein may be used
as tobacco-containing filter segments in single or multi-component
filters. For example, rods as described herein may be used as a
first flavor release segment in multi-component filters of the type
disclosed in EP-A-1 889 550.
[0078] Filters comprising rods as described herein may further
comprise one or more filtration materials for the removal of
particulate components, gaseous components or a combination
thereof. Suitable filtration materials are known in the art and
include, but are not limited to: fibrous filtration materials such
as, for example, cellulose acetate tow and paper; adsorbents such
as, for example, activated alumina, zeolites, molecular sieves and
silica gel; biodegradable polymers including, for example,
polylatic acid (PLA), Mater-Bi.RTM., and bioplastics; and
combinations thereof.
[0079] Alternatively or in addition, filters comprising rods as
described herein may further comprise one or more smoke or
aerosol-modifying agents. Suitable smoke and aerosol-modifying
agents are known in the art and include, but are not limited to:
flavourants such as, for example, menthol.
[0080] Preferably, rods according to the specification are of
substantially uniform cross-section.
[0081] Rods according to the specification may be produced having
different dimensions depending upon their intended use.
[0082] For example, rods according to the specification may have a
diameter of between about 5 mm and about 10 mm depending upon their
intended use.
[0083] For example, rods according to the specification may have a
rod length of between about 5 mm and about 150 mm depending upon
their intended use.
[0084] In preferred embodiments, rods according to the
specification for use as aerosol-forming substrates in heated
aerosol-generating articles may have a rod length of between about
5 mm and about 20 mm or about 30 mm.
[0085] In further embodiments, rods according to the specification
for use in filters for conventional lit-end smoking articles and
heated aerosol-generating articles may have a rod length of between
about 5 mm and about 30 mm.
[0086] Rods according to the specification of a desired unit rod
length may be produced by forming a rod of multiple unit rod length
and then cutting or otherwise dividing the rod of multiple unit rod
length into multiple rods of the desired unit rod length.
[0087] For example, rods having a rod length of about 15 mm for use
as aerosol-forming substrates in heated aerosol-generating articles
may be produced by forming a rod having a rod length of about 150
mm and then severing the elongate rod into ten rods having a rod
length of about 15 mm.
[0088] Preferred embodiments comprise sheets of homogenised tobacco
material. Sheets of homogenised tobacco material may be formed by
agglomerating particulate tobacco obtained by grinding or otherwise
comminuting one or both of tobacco leaf lamina and tobacco leaf
stems. Alternatively, or in addition, sheets of homogenised tobacco
material tobacco may comprise one or more of tobacco dust, tobacco
fines and other particulate tobacco by-products formed during, for
example, the treating, handling and shipping of tobacco. Where rods
according to the specification are intended for use as
aerosol-forming substrates in heated aerosol-generating articles,
sheets of homogenised tobacco material used to form the rods
preferably comprise particulate tobacco obtained by grinding or
otherwise comminuting tobacco leaf lamina.
[0089] In certain embodiments, sheets of homogenised tobacco
material may have a tobacco content of at least about 40% by weight
on a dry weight basis or of at least about 50% by weight on a dry
weight basis. In other embodiments, sheets of homogenised tobacco
material may have a tobacco content of about 70% or more by weight
on a dry weight basis. Where rods according to the specification
are intended for use as aerosol-forming substrates in heated
aerosol-generating articles, the use of sheets of homogenised
tobacco material having high tobacco contents advantageously
generates aerosols with enhanced tobacco flavour.
[0090] Sheets of homogenised tobacco material may comprise one or
more intrinsic binders, that is tobacco endogenous binders, one or
more extrinsic binders, that is tobacco exogenous binders, or a
combination thereof to help agglomerate the particulate tobacco.
Alternatively, or in addition, sheets of homogenised tobacco
material may comprise other additives including, but not limited
to, tobacco and non-tobacco fibres, aerosol-formers, humectants,
plasticisers, flavourants, fillers, aqueous and non-aqueous
solvents and combinations thereof.
[0091] Suitable extrinsic binders for inclusion in sheets of
homogenised tobacco material for use in forming a rod as described
herein are known in the art and include, but are not limited to:
gums such as, for example, guar gum, xanthan gum, arabic gum and
locust bean gum; cellulosic binders such as, for example,
hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl
cellulose, methyl cellulose and ethyl cellulose; polysaccharides
such as, for example, starches, organic acids, such as alginic
acid, conjugate base salts of organic acids, such as
sodium-alginate, agar and pectins; and combinations thereof.
[0092] Suitable non-tobacco fibres for inclusion in sheets of
homogenised tobacco material are known in the art and include, but
are not limited to: cellulose fibers; soft-wood fibres; hard-wood
fibres; jute fibres and combinations thereof. Prior to inclusion in
sheets of homogenised tobacco material, non-tobacco fibres may be
treated by suitable processes known in the art including, but not
limited to: mechanical pulping; refining; chemical pulping;
bleaching; sulfate pulping; and combinations thereof.
[0093] Sheets of homogenised tobacco material for use in forming
rods as described herein should have sufficiently high tensile
strength to survive being gathered to form rods. In certain
embodiments non-tobacco fibres may be included in sheets of
homogenised tobacco material in order to achieve an appropriate
tensile strength.
[0094] For example, homogenised sheets of tobacco material for
forming rods as described herein may comprise between about 1% and
about 5% non-tobacco fibres by weight on a dry weight basis.
[0095] Suitable aerosol-formers and humectants for inclusion in
sheets of homogenised tobacco material are known in the art and
include, but are not limited to: polyhydric alcohols, such as
triethylene glycol, 1,3-butanediol and glycerine; esters of
polyhydric alcohols, such as glycerol mono-, di- or triacetate; and
aliphatic esters of mono-, di- or polycarboxylic acids, such as
dimethyl dodecanedioate and dimethyl tetradecanedioate.
[0096] For example, where rods according to the specification are
intended for use as aerosol-forming substrates in heated
aerosol-generating articles, sheets of homogenised tobacco material
for use in forming rods as described herein may have an aerosol
former content of between about 5% and about 30% by weight on a dry
weight basis. Rods intended for use in electrically-operated
aerosol-generating system having a heating element may preferably
include an aerosol former of greater than 5% to about 30%. For rods
intended for use in electrically-operated aerosol-generating system
having a heating element, the aerosol former may preferably be
glycerine.
[0097] It will be appreciated that the composition of sheets of
homogenised tobacco material may be designed to comply with
regulatory requirements.
[0098] A number of reconstitution processes for producing sheets of
homogenised tobacco materials are known in the art. These include,
but are not limited to: paper-making processes of the type
described in, for example, U.S. Pat. No. 3,860,012; casting or
`cast leaf` processes of the type described in, for example, U.S.
Pat. No. 5,724,998; dough reconstitution processes of the type
described in, for example, U.S. Pat. No. 3,894,544; and extrusion
processes of the type described in, for example, in GB-A-983,928.
Typically, the densities of sheets of homogenised tobacco material
produced by extrusion processes and dough reconstitution processes
are greater than the densities of sheets of homogenised tobacco
materials produced by casting processes.
[0099] Sheets of homogenised tobacco material for use in forming
rods as described herein are preferably formed by a casting process
of the type generally comprising casting a slurry comprising
particulate tobacco and one or more binders onto a conveyor belt or
other support surface, drying the cast slurry to form a sheet of
homogenised tobacco material and removing the sheet of homogenised
tobacco material from the support surface.
[0100] For example, in certain embodiments sheets of homogenised
tobacco material may be formed from slurry comprising particulate
tobacco, guar gum, cellulose fibres and glycerine by a casting
process.
[0101] Sheets of homogenised tobacco material may be textured using
suitable known machinery for texturing filter tow, paper and other
materials.
[0102] For example, sheets of homogenised tobacco material for
forming rods as described herein may be crimped using a crimping
unit of the type described in CH-A-691156, which comprises a pair
of rotatable crimping rollers. However, it will be appreciated that
sheets of homogenised tobacco material may be textured using other
suitable machinery and processes that deform or perforate the
sheets of homogenised tobacco material.
[0103] Rods according to the specification may be produced from
sheets of homogenised tobacco material that have a range of
different dimensions, depending upon the intended use of the rods.
Sheets of homogeneous tobacco material should be of sufficient
width to be gathered to form a rod as described herein.
[0104] Preferably, sheets of tobacco material for use in rods as
described herein have a width of at least about 25 mm.
[0105] In certain embodiments sheets of tobacco material for use in
rods as described herein may have a width of between about 25 mm
and about 300 mm.
[0106] Preferably, sheets of tobacco material for use in rods as
described herein have a combined thickness of at least about 50
.mu.m to about 100 .mu.m. Combined thickness refers to the total
thickness of all sheets that make up the rod. For example, if the
rod is formed from two sheets, then the combined thickness is the
sum of the thickness of each individual sheet. Sheets of tobacco
material for use in rods as described herein may have individual
thicknesses of between about 25 .mu.m to about 100 .mu.m.
[0107] In certain embodiments, sheets of tobacco material for use
in rods as described herein may have a thickness of between 10
.mu.m and about 300 .mu.m.
[0108] In certain embodiments, sheets of homogenised tobacco
material for use in rods as described herein may have a grammage
100 g/m.sup.2 and about 300 g/m.sup.2.
[0109] Rods as described herein may comprise a gathered sheet of
homogenised tobacco material circumscribed by a porous wrapper or a
non-porous wrapper.
[0110] In certain embodiments, rods as described herein may
comprise at least two sheets of homogenised tobacco material
gathered together and circumscribed by a paper wrapper.
[0111] Suitable paper wrappers for use in specific embodiments of
the invention are known in the art and include, but are not limited
to: cigarette papers; and filter plug wraps.
[0112] In other embodiments, rods as described herein may comprise
a non-paper wrapper. Suitable non-paper wrappers for use in forming
rods as described herein are known in the art and include, but are
not limited to: homogenised tobacco materials.
[0113] Rods as described herein may be produced using conventional
cigarette making and cigarette filter making machinery, adapted to
allow for the gathering of two or more sheets simultaneously.
[0114] For example, rods comprising first and second crimped sheets
of homogeneous tobacco material may be produced using an adaptation
of machinery for forming filter rods comprising a gathered crimped
sheet of paper of the type described in CH-A-691156. The machinery
could be adapted to allow two sheets of material to be crimped and
gathered.
[0115] A method of forming a rod may be provided comprising the
steps of: providing a first continuous sheet of tobacco material,
providing a second continuous sheet of tobacco material,
simultaneously gathering the first and second continuous sheets of
tobacco material transversely relative to the longitudinal axes
thereof; circumscribing the gathered sheets of tobacco material
with a wrapper to form a continuous rod, and severing the
continuous rod into a plurality of discrete rods, in which the
first continuous sheet of tobacco material is physically or
chemically different to the second continuous sheet of tobacco
material.
[0116] The method may further comprise texturing the first
continuous sheet. For example, the method may comprise crimping,
embossing, perforating or otherwise texturing the first continuous
sheet prior to gathering the first continuous sheet together with
the second continuous sheet.
[0117] Preferably, the method further comprises crimping the first
continuous sheet. Both first and second continuous sheets may be
textured, for example crimped. Both first and second sheets of
tobacco material may be crimped prior to being gathered.
[0118] Specific embodiments will be further described, by way of
example only, with reference to the accompanying drawings in
which:
[0119] FIG. 1 shows a schematic cross-section of apparatus for
forming a rod according to a specific embodiment;
[0120] FIG. 2 shows a schematic cross-section of apparatus for
forming a rod according to a specific embodiment;
[0121] FIGS. 3 to 8 illustrate cross-sectional views of sheets of
tobacco material immediately prior to entering a gathering means to
be gathered into a rod;
[0122] FIGS. 9 and 10 illustrate embodiments of aerosol-generating
devices that incorporate rods formed as described herein; and
[0123] FIG. 11 illustrates an aerosol-generating system comprising
an electrically-operated aerosol-generating device and an
aerosol-generating article as illustrated in FIG. 9.
[0124] The apparatus shown in FIG. 1 generally comprises: first
supply means for providing a first continuous sheet of homogenised
tobacco material; second supply means for providing a second
continuous sheet of homogenised material; crimping means for
crimping the first continuous sheet of homogenised tobacco
material; rod forming means for gathering both the first and second
continuous sheets of homogenised tobacco material together and
circumscribing the gathered material with a wrapper to form a
continuous rod; and cutting means for severing the continuous rod
into a plurality of discrete rods. The apparatus also comprises
transport means for transporting at least the first continuous
sheet of homogenised tobacco material downstream through the
apparatus from the supply means to the rod forming means via the
crimping means.
[0125] As shown in FIG. 1, the first supply means for providing a
first continuous sheet of homogenised tobacco material comprises a
continuous sheet of homogenised tobacco material 2 mounted on a
first bobbin 4. The second supply means for providing a second
continuous sheet of homogenised tobacco material comprises a
continuous sheet of homogenised tobacco material 3 mounted on a
second bobbin 5. The crimping means comprises a pair of rotatable
crimping rollers 6. In use, the first continuous sheet of
homogenised tobacco material 2 is drawn from the first bobbin 4 and
transported downstream to the pair of crimping rollers 6 by the
transport mechanism via a series of guide and tensioning rollers.
As the continuous sheet of homogenised tobacco material 2 is fed
between the pair of crimping rollers 6, the crimping rollers engage
and crimp the first continuous sheet of homogenised tobacco
material 2 to form a first continuous crimped sheet of homogenised
tobacco material 8 having a plurality of spaced-apart ridges or
corrugations substantially parallel to the longitudinal axis of the
sheet of homogenised tobacco material through the apparatus.
[0126] The first continuous crimped sheet of homogenised tobacco
material 8 is transported downstream from the pair of crimping
rollers 6 towards the rod forming means. The second continuous
sheet of homogenised tobacco material 3 is transported from the
second bobbin 5 towards the rod forming means. Both the second
continuous sheet of homogenised tobacco material 3 and the first
continuous sheet of crimped homogenised tobacco material 8 are
simultaneously fed through a converging funnel or horn 10. The
converging funnel 10 gathers the continuous sheets of material 8, 3
transversely relative to their longitudinal axes. The continuous
sheets of material 8,3 assume a substantially cylindrical
configuration as they pass through the converging funnel 10.
[0127] Upon exiting the converging funnel 10, the gathered sheets
of homogenised tobacco material are wrapped in a continuous sheet
of wrapping material 12. The continuous sheet of wrapping material
is fed from a bobbin 14 and enveloped around the gathered sheets of
material by an endless belt conveyor or garniture. As shown in FIG.
1, the rod forming means comprises an adhesive application means 16
that applies adhesive to one of the longitudinal edges of the
continuous sheet of wrapping material, so that when the opposed
longitudinal edges of the continuous sheet of wrapping material are
brought into contact they adhere to one other to form a continuous
rod.
[0128] The rod forming means further comprises a drying means 18
downstream of the adhesive application means 16, which in use dries
the adhesive applied to the seam of the continuous rod as the
continuous rod is transported downstream from the rod forming means
to the cutting means.
[0129] The cutting means comprises a rotary cutter 20 that severs
the continuous rod into a plurality of discrete rods of unit rod
length or multiple unit rod length.
[0130] As the two continuous sheets of material are fed into the
converging funnel while overlaid, one sheet on top of the other,
the rod has an even distribution of the first sheet of tobacco
material and the second sheet of tobacco material.
[0131] Although the second continuous sheet of homogenised tobacco
material is depicted as being gathered into a rod without being
crimped, it is clear that this second continuous sheet may pass
through a set of crimping rollers to be crimped prior to being
gathered into a rod.
[0132] To manufacture a rod comprising a sheet of a first tobacco
material and a continuous element of a second tobacco material
having a different chemical composition to the first tobacco
material, the second sheet of homogenised tobacco material on the
second bobbin (as illustrated in FIG. 1) could be replaced with a
bobbin holding a suitable continuous element. Such an element may
take the form of a ribbon, strip, tape or thread. Operation of the
process would otherwise be as described above.
[0133] In an alternative configuration illustrated in FIG. 2, a
second continuous sheet of homogenised tobacco material 3 is
positioned in overlapping relationship with a first continuous
sheet of homogenised tobacco material 2 upstream of a pair of
crimping rollers 6. The apparatus is otherwise substantially as
described above in relation to FIG. 1.
[0134] Both continuous sheets of material 2,3 pass through the
crimping rollers 6 in overlapping relationship and are
simultaneously crimped. A crimped pair of continuous sheets 9
passes out of the crimping rollers 6 and downstream into the
converging funnel 10 to be formed into a rod.
[0135] FIGS. 3 to 8 provide schematic cross-sectional illustrations
of different possible arrangements of two sheets of tobacco
material immediately prior to entering into a converging funnel or
horn in order to be gathered into a rod. All of these Figures
illustrate the relative thickness, width, and cross-sectional shape
of each sheet of tobacco. The length dimension of each of the
sheets in these schematic illustrations extends into the plane of
the paper.
[0136] FIG. 3 illustrates an arrangement in which a first sheet of
tobacco material 300 is overlaid with a second sheet of tobacco
material 310 of the same dimensions prior to both sheets entering a
gathering device to be gathered into a rod. While the physical
dimensions of each sheet are the same, the chemical composition of
each sheet is different.
[0137] FIG. 4 illustrates an arrangement in which a first sheet of
tobacco material 400 is overlaid with a second sheet of tobacco
material 410 that has a smaller thickness dimension compared to the
first tobacco sheet 400. While the physical dimensions of each
sheet differ, in that one sheet is thinner than the other, the
chemical composition of each sheet may be identical. In preferred
embodiments, however, the chemical composition of each sheet will
also differ.
[0138] FIG. 5 illustrates an arrangement in which a first sheet of
tobacco material 500 is positioned adjacent to a second sheet of
tobacco material 510 of the same dimensions prior to both sheets
entering a gathering device to be are gathered into a rod. While
the physical dimensions of each sheet are the same, the chemical
composition of each sheet is different.
[0139] FIG. 6 illustrates an arrangement in which a first sheet of
tobacco material 600 is overlaid with a second sheet of tobacco
material 610 prior to both sheets entering a gathering device to be
gathered into a rod. The second sheet has been crimped. The
composition of the two sheets may be the same or different.
[0140] FIG. 7 illustrates an arrangement in which a first crimped
sheet of tobacco material 700 is overlaid with a second crimped
sheet of tobacco material 710 prior to both sheets entering a
gathering device to be gathered into a rod. While the physical
dimensions of each sheet are the same, the chemical composition of
each sheet is different.
[0141] FIG. 8 illustrates an arrangement in which a first sheet of
tobacco material 800 is overlaid with a second sheet of tobacco
material 810 prior to both sheets entering a gathering device to be
gathered into a rod. The second sheet 810 has a lesser width and
thickness compared with the first sheet 800.
[0142] The skilled person will appreciate that many more
arrangements of two or more sheets of tobacco material may be
possible.
[0143] FIG. 9 illustrates an embodiment of an aerosol-generating
article 1000 comprising a rod as described herein. The article 1000
comprises four elements; an aerosol-forming substrate 1020, a
hollow cellulose acetate tube 1030, a spacer element 1040, and a
mouthpiece filter 1050. These four elements are arranged
sequentially and in coaxial alignment and are assembled by a
cigarette paper 1060 to form the aerosol-generating article 1000.
The article 1000 has a mouth-end 1012, which a user inserts into
his or her mouth during use, and a distal end 1013 located at the
opposite end of the article to the mouth end 1012. The embodiment
of an aerosol-generating article illustrated in FIG. 9 is
particularly suitable for use with an electrically-operated
aerosol-generating device comprising a heater for heating the
aerosol-forming substrate.
[0144] When assembled, the article 1000 is about 45 millimetres in
length and has an outer diameter of about 7.2 millimetres and an
inner diameter of about 6.9 millimetres.
[0145] The aerosol-forming substrate 1020 comprises a rod formed
from a first sheet of crimped cast-leaf tobacco and a second sheet
of crimped cast-leaf tobacco wrapped in a filter paper (not shown)
to form a plug. Both sheets of cast-leaf tobacco include additives,
including glycerine as an aerosol-forming additive. The first sheet
of cast-leaf tobacco and the second sheet of cast-leaf comprise
different blends of tobacco and therefore differ chemically.
[0146] An aerosol-generating article 1000 as illustrated in FIG. 9
is designed to engage with an aerosol-generating device in order to
be consumed. Such an aerosol-generating device includes means for
heating the aerosol-forming substrate 1020 to a sufficient
temperature to form an aerosol. Typically, the aerosol-generating
device may comprise a heating element that surrounds the
aerosol-generating article 1000 adjacent to the aerosol-forming
substrate 1020, or a heating element that is inserted into the
aerosol-forming substrate 1020.
[0147] Once engaged with an aerosol-generating device, a user draws
on the mouth-end 1012 of the smoking article 1000 and the
aerosol-forming substrate 1020 is heated to a temperature of about
375 degrees Celsius. At this temperature, volatile compounds are
evolved from the two different sheets of cast-leaf tobacco of the
aerosol-forming substrate 1020. These compounds condense to form an
aerosol. The aerosol is drawn through the filter 1050 and into the
user's mouth.
[0148] FIG. 10 illustrates a second embodiment of an
aerosol-generating article 1001. While the article of FIG. 9 is
intended to be consumed in conjunction with an aerosol-generating
device, the article of FIG. 10 comprises a combustible heat source
1080 that may be ignited and transfer heat to the aerosol-forming
substrate 1020 to form an inhalable aerosol. The combustible heat
source 80 is a charcoal element that is assembled in proximity to
the aerosol-forming substrate at a distal end 13 of the rod 11.
Elements that are essentially the same as elements in FIG. 9 have
been given the same numbering.
[0149] FIG. 11 illustrates a portion of an electrically-operated
aerosol-generating system 2000 that utilises a heating blade 2100
to heat an aerosol-generating substrate 1020 of an
aerosol-generating article 1000. The heating blade is mounted
within an aerosol article receiving chamber of an
electrically-operated aerosol-generating device 2010. The
aerosol-generating device defines a plurality of air holes 2050 for
allowing air to flow to the aerosol-generating article 1000. Air
flow is indicated by arrows on FIG. 11. The aerosol-generating
device comprises a power supply and electronics, which are not
illustrated in FIG. 11. The aerosol-generating article 1000 of FIG.
11 is as described in relation to FIG. 9.
EXAMPLE 1
[0150] Rods according to a specific embodiment of the invention
comprise a first crimped sheet of homogenised tobacco material
gathered together with a second crimped sheet of homogenised
tobacco material, and circumscribed by a paper wrapper. The rods
have a rod length of 12 mm and diameters of between 6.9 mm and 7.2
mm. The rods were produced at rates of between 20 m/min and 25
m/min using apparatus of the type shown in FIG. 1.
[0151] The first continuous sheet of homogenised tobacco material
was produced by a casting process, the sheets having a width of
between 110 mm and 134 mm, a thickness of 120 .mu.m to 260 .mu.m, a
grammage of between 167 g/m.sup.2 and 201 g/m.sup.2 and a moisture
content of between 5% and 12%. The first continuous sheet comprises
about 10% by weight of glycerine.
[0152] The second continuous sheet of homogenised tobacco material
was produced by a casting process, the sheets having a width of
between 110 mm and 134 mm, a thickness of 120 .mu.m to 260 .mu.m, a
grammage of between 167 g/m.sup.2 and 201 g/m.sup.2 and a moisture
content of between 5% and 12%. The second continuous sheet
comprises about 10% by weight of propylene glycol.
[0153] The first continuous sheet of homogenised tobacco and the
second continuous sheet of homogenised tobacco were crimped by
being arranged in overlapping relationship and passing through a
crimping roller together prior to being gathered into a rod.
[0154] The exemplary embodiments and example described above are
not limiting. In view of the above-discussed exemplary embodiments,
other embodiments consistent with the above exemplary embodiment
will now be apparent to one of ordinary skill in the art.
* * * * *