Note: Descriptions are shown in the official language in which they were submitted.
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SMOKING ARTICLE
Technical Field
The present invention relates to smoking articles and specifically, although
not
exclusively, to a wrapper for an aerosol generating material, an aerosol
generating
article comprising a wrapped aerosol generating material, and an aerosol
generating
assembly containing an aerosol generating article, the aerosol generating
article
comprising a wrapped aerosol generating material.
Background
Smoking articles such as cigarettes, cigars and the like burn tobacco during
use
to create tobacco smoke. Alternatives to these types of articles, release
compounds by
heating without burning an aerosol generating material.
Apparatus is known that heats aerosol generating material to volatilise at
least
one component of the aerosol generating material, typically to form an aerosol
which
can be inhaled, without burning or combusting the aerosol generating material.
Such
apparatus is sometimes described as a "heat-not-burn" apparatus or a "tobacco
heating
product" (THIP) or a "tobacco heating device" or similar. Various different
arrangements for volatilising at least one component of the aerosol generating
material
are known.
The material may be for example tobacco, other non-tobacco products or a
combination, such as a blended mix, which may or may not contain nicotine.
Summary
The invention provides a wrapper for wrapping an aerosol generating material,
wherein the wrapper is a laminate structure comprising at least three layers,
and
wherein; (a) one of the peripheral layers comprises a lacquer; (b) an
intermediate layer
comprises a non-combustible material; and (c) the peripheral layer comprises
paper.
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The invention also provides an aerosol generating article, the aerosol
generating
article, the aerosol generating article comprising an aerosol generating
material and a
laminate wrapper arranged around the aerosol generating material, the laminate
wrapper comprising at least three layers;
wherein the outermost layer of the laminate wrapper comprises a lacquer, an
intermediate layer comprises a non-combustible material, and the innermost
layer
comprises paper;
and wherein at least part of the innermost layer is disposed in contact with
the
aerosol generating material.
In some cases, the lacquer of the outermost layer has a dynamic coefficient of
friction greater than or equal to about 0.4. In some cases, the lacquer of the
outermost
layer has a static coefficient of friction greater than or equal to about 0.4.
In some cases,
the lacquer of the outermost layer has a dynamic coefficient of friction less
than or equal
to about 1Ø In some cases, the lacquer of the outermost layer has a static
coefficient
of friction less than or equal to about 1.1. In some cases, the lacquer of the
outermost
layer has a dynamic coefficient of friction of from 0.4 to 1Ø In some cases,
the lacquer
of the outermost layer has a static coefficient of friction of from 0.4 to
1.1. The
coefficient of friction is measured in all cases according to DIN EN ISO 8295.
The invention also provides an aerosol generating assembly, the assembly
comprising a heater and an aerosol generating article, the aerosol generating
article
comprising an aerosol generating material and a laminate wrapper arranged
around the
aerosol generating material, the laminate wrapper comprising at least three
layers;
wherein the outermost layer of the laminate wrapper comprises a lacquer, an
intermediate layer comprises a non-combustible material, and the innermost
layer
comprises paper;
and wherein at least part of the innermost layer is disposed in contact with
the
aerosol generating material.
In some cases, the aerosol generating assembly may be a tobacco heating
product (also known as a heat not burn device).
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The invention also provides a system comprising an aerosol generating device
and an aerosol generating article, the aerosol generating article comprising
an aerosol
generating material and a laminate wrapper arranged around the aerosol
generating
material, the laminate wrapper comprising at least three layers;
wherein the outermost layer of the laminate wrapper comprises a lacquer, an
intermediate layer comprises a non-combustible material, and the innermost
layer
comprises paper;
and wherein at least part of the innermost layer is disposed in contact with
the
aerosol generating material.
The invention also provides a process for making an aerosol generating article
comprising wrapping an aerosol generating material in a laminate wrapper, the
laminate
wrapper comprising at least three layers;
wherein the outermost layer of the laminate wrapper comprises a lacquer, an
intermediate layer comprises a non-combustible material, and the innermost
layer
comprises paper;
and wherein at least part of the innermost layer is disposed in contact with
the
aerosol generating material.
The invention also provides a method of preventing a user lighting or igniting
an aerosol generating material in aerosol generating article, the method
comprising
wrapping an aerosol generating material in a laminate wrapper, the laminate
wrapper
comprising at least three layers;
wherein the outermost layer of the laminate wrapper comprises a lacquer, an
intermediate layer comprises a non-combustible material, and the innermost
layer
comprises paper;
and wherein at least part of the innermost layer is disposed in contact with
the
aerosol generating material.
To the extent that they are compatible, features of the invention described in
the
context of one aspect are explicitly disclosed in combination with each other
aspect.
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Figures
Further features and advantages of the invention will become apparent from the
following figures description of examples of the invention, given by way of
example
only and do not place any limitation on the scope of the claims.
Figure 1 is a schematic diagram of a side view of an aerosol generating
article
according to an example of the invention.
Figure 2 is a schematic diagram of a first end view of an aerosol generating
article according to an example of the invention.
Figure 3 is a schematic diagram of a first end view of a different aerosol
generating article according to an example of the invention.
Figure 4 is a schematic diagram of a side view of an aerosol generating
article
according to an example of the invention.
Figure 5 is an exploded schematic diagram of a wrapper according to an
example of the invention.
Detailed Description
As used herein, the term "lacquer" refers to a coating, formed from polymers
dissolved in volatile organic compounds, where the solvent is removed by
evaporation,
effecting curing of the polymers to produce a hard, durable finish.
The lacquer may be an acrylic lacquer. In some examples, the lacquer may be
a styrene acrylic copolymer dispersion.
As used herein, the term "laminate" refers to a multi-layer structure in which
the layers are fastened together to form a single body. The layers may be
fastened with
an adhesive, for example. In other examples, the layers may be fastened by
static
interaction. In other examples, the laminate structure might be formed by
(partially)
melting a first layer, contacting the first layer with a second layer and
allowing the first
layer to solidify. Any suitable mechanism for fastening the layers together
including,
but not limited to, the above examples, tying, sewing, screwing, nailing,
bolting,
hooking etc. may be employed to form the laminate structure.
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In some cases, an adhesive may coat the surface of each layer. In other cases,
an adhesive may be applied only to the periphery of the layers. In some cases,
each
layer in the laminate structure may be fastened to the adjacent layer(s). In
some
5 example laminate structures, the periphery of two layers may be fastened
together with
intermediate layers trapped in-between.
The peripheral layers may be referred to herein as the "innermost" and
"outermost" layers. This refers to their location when the material is wrapped
around
an aerosol generating material.
In some examples, the wrapper comprises more than three layers. In some
cases, the wrapper consists of three layers. In some cases, the wrapper may
consist of
a three layer laminate structure comprising the peripheral layers and the
intermediate
layer.
Figure 5 is a schematic illustration of a laminate wrapper according to the
invention. The laminate structure (indicated by dotted lines) includes the
peripheral
layers 501,503 and the intermediate layer 502.
In some cases, the non-combustible material comprises a metal foil. In some
cases, it may consist essentially of or consist of a metal foil. Suitably, the
metal foil
may comprise, essentially consist of or consist of an aluminium foil. The
metal foil is
a non-combustible material that can nevertheless act to conduct heat to the
aerosol
generating material in use.
In some cases, the metal foil may be less than about 100 [tm, 50 [tm, 20 [tm,
10 [tm or 8 [tm thick. In some cases, it may be more than about 1 [tm, 3 [tm
or 5 [tm
thick.
In some cases, the paper layer in the wrapper is a tobacco wrapping paper.
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A consideration when preparing aerosol generating articles such as tobacco
heating products is that they should not produce an acceptable smoking
experience if
combusted, so that the user is not minded to burn the aerosol generating
article. This is
because the formulation of the aerosol generating material is not configured
for
combustion (and the aerosol that results from combustion may be less suitable
for
inhalation than the aerosol that results from heating but not burning that
aerosol
generating material, or than the aerosol which results from combustion of
traditional
cigarettes).
The use of a non-combustible layer in the wrapper prevents the aerosol
generating article from being burned and smoked as a conventional combustible
cigarette.
Additionally, the inventors have found that the outer surface temperature of
laminate wrappers described herein which have an intermediate layer comprising
foil
cool faster that comparative wrappers which comprise only paper. This eases
handling
for the user, and may be due to the higher thermal conductivity of the
intermediate foil
layer.
As used herein, the phrase "non-combustible" refers to a material that will
not
ignite or burn at temperatures normally associated with lighting (igniting) or
burning of
tobacco.
Further, the use of a metal foil layer results in a wrapper that has a low
porosity,
reducing side stream air flow to the aerosol generating material. This further
reduces
the propensity to burn through limiting the oxygen levels at the aerosol
generating
material.
Moreover, the inventors established that having peripheral surfaces with a
coefficient of friction that is higher than a certain value is beneficial
because this makes
the wrapper easier to handle and process during the manufacturing process. It
allows
known machinery to be more readily employed. Specifically, this allows the
garniture
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belt of an aerosol generating article making machine to drive the laminate
wrapper
through the garniture during the aerosol generating article manufacturing
process.
The lacquer may provide improved surface properties for the laminate wrapper.
For example, the lacquer may have a coefficient of friction that is
sufficiently high to
improve handling during manufacture. (Surfaces that are too smooth may slip in
manufacturing machinery.) Additionally, the lacquer aids in adhering the
wrapper to
itself when arranged around the aerosol generating material, since the lacquer
retains
adhesive on its surface and adheres more readily than the intermediate metal
foil layer.
Additionally, the lacquer may provide resistance to corrosion of the metal
foil
layer. Metals such as aluminium may corrode, for example oxidise, in use or
upon
storage, and the presence of the lacquer may mitigation this corrosion.
In some cases, the paper in the innermost layer of the wrapper may have a
basis
weight of at least about 10 g.m-2, 15 g.m-2, 20 g.m-2 or 25 g.m-2 to about 50
g.m-2,
45 g.m-2, 40 g.m-2 or 35 g.m-2. Paper having a density in this range has a low
porosity,
which further reduces the propensity to burn through limiting the oxygen
levels at the
aerosol generating material.
In some cases, the innermost layer may also comprise a flavourant, which is
transferred to the aerosol generating material when wrapped around the aerosol
generating material and heated. In some cases, the flavourant may comprise
menthol.
In some cases, the paper in the innermost layer of the wrapper may be treated
with one or more burn-retardant substances.
In some cases, the wrapper can be wound onto a bobbin core for use with
standard cigarette makers that are fed from a single paper bobbin.
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In some cases, one or more ventilation apertures may be formed in the wrapper.
The ventilation apertures may provide airflow into the aerosol-generating
article during
use, the air forming part of the inhaled aerosol.
The laminate wrapper may be formed using any suitable lamination technique.
In one example, the layers may be adhered together.
In some examples of the aerosol generating article described herein, at least
part
of the innermost layer is disposed in contact with the aerosol generating
material.
In some cases, the aerosol generating material comprises tobacco. The tobacco
may be any suitable solid tobacco, such as single grades or blends, cut rag or
whole
leaf, ground tobacco, tobacco fibre, cut tobacco, extruded tobacco, tobacco
stem and/or
reconstituted tobacco. The tobacco may be of any type including, but not
limited to,
Virginia and/or Burley and/or Oriental tobacco.
In some examples, the aerosol generating material may be a rod of aerosol
generating material. As used herein, the term "rod" generally refers to an
elongate body
which may be any suitable shape for use in an aerosol generating assembly. In
some
cases, the rod is substantially cylindrical.
In some cases where the aerosol generating material is a rod of aerosol
generating material, the wrapper circumscribes at least the end of the rod
that is distant
from the user's mouth in use (i.e. a distal-end rather than a mouth-end). This
ensures
that the non-combustible wrapper is disposed around the end of the rod which
the user
might try to ignite. In some cases, the laminate wrapper circumscribes the rod
over at
least 25% of the rod length. In some cases, the wrapper extends over at least
35%, 40%,
45% or 50% of the rod length. As more of the rod is circumscribed, burning of
the rod
is more difficult.
In some cases, the wrapper does not extend over the entire length of the rod
of
aerosol generating material, resulting in cost savings. In some cases, the
laminate
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wrapper extends over less than about 85%, 80%, 75%, 70%, 65% or 60% of the rod
length.
Figure 1 illustrates an example aerosol generating article. The aerosol
generating article 101 includes an aerosol generating material 103 which is
wrapped by
a laminate wrapper 102. In this example, this wrapper extends from the distal-
end of
the aerosol generating material over approximately 50% of the distance to the
mouth-
end of the aerosol generating material. In some examples, the wrapper 102
comprises
three layers, wherein the outermost layer comprises a lacquer, the innermost
layer
comprises paper and the intermediate layer comprises a non-combustible
material.
Optionally, the wrapper may also be arranged over the distal-end of the
aerosol
generating material, so that the distal-end is completely enclosed in the
wrapper. Figure
2 illustrates an example in which the wrapper 102 is wrapped around the
circumference
of the aerosol generating material 103. The distal-end of the aerosol
generating article
101 is not covered by the wrapper. Figure 3 illustrates an alternative example
of an
aerosol generating article 101 in which the wrapper 102 completely encloses
the distal-
end of the aerosol generating article.
Examples of the aerosol generating article may additionally comprise a filter
and/or a cooling element. In some cases, the cooling element may be arranged
between
the aerosol generating material and the filter. In some cases, the filter may
be arranged
between the aerosol generating material and the cooling element.
The filter and/or cooling element may be joined to the aerosol generating
material by a wrapping material that circumscribes these components. This may,
in
some cases, be the laminate wrapper discussed above.
For example, the mouth-end of the aerosol generating material may be provided
adjacent to one or more of a cooling element and a filter. A cooling element,
if present,
allows vapour components to condense to form an aerosol and/or spaces the very
hot
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parts of the apparatus from the user. A filter, if present, may remove
components from
the fluid flow, affecting the chemical composition of the inhaled aerosol.
Figure 4 illustrates an example of an aerosol generating article 101 which
5 includes, in addition to the features of figure 1, a cooling element 104,
a filter 105 and
a mouth-end tube 106. The cooling element 104 and filter 105, as illustrated,
may be
arranged between the mouth-end of the aerosol generating material 103 and the
mouth-
end tube 106, so that flow from the aerosol generating material 103 passes
through the
cooling element 104 and filter 105 (or vice versa if the filter is arranged
before the
10 cooling element in the flow) before reaching the user. Although the
example in Figure
4 illustrates a cooling element 104, a filter 105 and a mouth-end tube 106,
one or more
of these elements may be omitted in other examples.
In some examples, the mouth-end tube, if present, 106 may be formed of for
example paper, for example in the form of a spirally wound paper tube,
cellulose
acetate, cardboard, crimped paper, such as crimped heat resistant paper or
crimped
parchment paper, and/or polymeric materials, such as low density polyethylene
(LDPE), or some other suitable material. The mouth-end tube 106 may be a
hollow
tube. Such a hollow tube may provide a filtering function to filter
volatilised aerosol
generating material. The mouth-end tube 106 may be elongate, in order to be
spaced
from the very hot part(s) of the main apparatus (not shown) that heats the
aerosol
generating material.
In some examples, the filter 105, if present, may be a filter plug, and may be
.. made, for example, from cellulose acetate.
In some cases, the cooling element 104, if present, may comprise a monolithic
rod having first and second ends and comprising plural through holes extending
between the first and second ends. The through holes may extend substantially
parallel
to the central longitudinal axis of the rod. The through holes of the cooling
element
104 may be arranged generally radially of the element when viewed in lateral
cross-
section. That is, in an example, the element has internal walls which define
the through
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holes and which have two main configurations, namely radial walls and central
walls.
The radial walls extend along radii of the cross-section of the element and
the central
walls are centred on the centre of the cross-section of the element. The
central walls in
one example are circular, though other regular or irregular cross-sectional
shapes may
be used. Likewise, the cross-section of the element in one example is
circular, though
other regular or irregular cross-sectional shapes may be used.
In an example, the majority of the through holes have a hexagonal or generally
hexagonal cross-sectional shape. In this example, the element has what might
be
termed a "honeycomb" structure when viewed from one end.
In some cases, the cooling element 104 may comprise a hollow tube which
spaces the filter 105, if present, from the very hot part(s) of the main
apparatus that
heats the aerosol generating material. The cooling element 104 may be formed
of for
example paper, for example in the form of a spirally wound paper tube,
cellulose
acetate, cardboard, crimped paper, such as crimped heat resistant paper or
crimped
parchment paper, and polymeric materials, such as low density polyethylene
(LDPE),
or some other suitable material.
The cooling element 104, if present, may be substantially incompressible. It
may be formed of a ceramic material, or of a polymer, for example a
thermoplastic
polymer, which may be an extrudable plastics material. In an example, the
porosity of
the element is in the range 60% to 75%. The porosity in this sense may be a
measure
of the percentage of the lateral cross-sectional area of the element occupied
by the
through holes. In an example, the porosity of the element is around 69% to
70%.
Other examples of aerosol-cooling element are disclosed in
PCT/GB2015/051253, the entirety of which is hereby expressly incorporated by
reference, in particular in Figures 1 to 8 and the description from page 8,
line 11 to page
18, line 16.
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In further examples, the cooling element 104 may be formed from a sheet
material that is folded, crimped or pleated to form through holes. The sheet
material
may be made, for example, from metal such as aluminium; polymeric plastics
material
such as polyethylene, polypropylene, polyethylene terephthalate, or polyvinyl
chloride;
or paper.
In some examples, the cooling element 104 and the filter 105 may be held
together by a wrapper paper to form an assembly. The assembly may then be
joined to
the aerosol generating material by a further wrapper which circumscribes the
assembly
and at least the mouth end of the aerosol generating material to form the
aerosol
generating article 101. In other examples, the aerosol generating article 101
is formed
by wrapping the cooling element 104, the filter 105 and the aerosol generating
material
103 effectively in one operation, with no separate tipping paper being
provided for the
cooling element and/or filter components (if present).
In some cases, one or more ventilation apertures may be formed in the aerosol-
generating article. The ventilation apertures may provide airflow into the
article during
use which forms part of the inhaled aerosol. It may be desirable to reduce
airflow over
the distal-end of the article to reduce the propensity to burn, and so the
apertures may
be formed nearer to the mouth-end of the article than to the distal-end. For
example,
the ventilation apertures may be formed in the cooling element and/or filter,
if present.
Moreover, the ventilation holes may be formed in a part of the article that is
not wrapped
in the non-combustible material. The inventors have established that cutting
the non-
combustible material to form ventilation apertures may not be straightforward.
In use, in some cases, the aerosol generating article may be arranged at least
partially within a heating device to form an aerosol generating assembly which
heats
the article to generate an aerosol without burning. In some other cases, the
article may
be provided in an assembly with a fuel source, such as a combustible fuel
source or
chemical heat source, which heats but does not burn the aerosol generating
material.
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The above examples are to be understood as illustrative examples of the
invention. It is to be understood that any feature described in relation to
any one
example may be used alone, or in combination with other features described,
and may
also be used in combination with one or more features of any other of the
examples, or
any combination of any other of the examples. Furthermore, equivalents and
modifications not described above may also be employed without departing from
the
scope of the invention, which is defined in the accompanying claims.
