[0001] The present invention relates to an aerosol-generating article for producing aerosol
upon heating. An aerosol-generating system comprising the aerosol-generating article
and an aerosol-generating device is also described in the present specification.
[0002] Aerosol-generating articles in which an aerosol-forming substrate, such as a tobacco-containing
substrate, is heated rather than combusted, are known in the art. Typically in such
heated aerosol-generating articles, an aerosol is generated by the transfer of heat
from a heat source to a physically separate aerosol-forming substrate or material,
which may be located in contact with, within, around, or downstream of the heat source.
During use of the aerosol-generating article, volatile compounds are released from
the aerosol-forming substrate by heat transfer from the heat source and are entrained
in air drawn through the aerosol-generating article. As the released compounds cool,
they condense to form an aerosol.
[0003] A number of prior art documents disclose aerosol-generating devices for consuming
aerosol-generating articles. Such devices include, for example, electrically heated
aerosol-generating devices in which an aerosol is generated by the transfer of heat
from one or more electrical heater elements of the aerosol-generating device to the
aerosol-forming substrate of a heated aerosol-generating article.
[0004] WO 2019/224366 A1 describes an aerosol generating article comprising a cylindrical rod of aerosolisable
material and a filter assembly in the form of a rod. The filter assembly includes
three segments, a cooling segment, a filter segment and a mouth end segment. The cooling
segment may be an annular tube. A ventilation region may be provided in the article
and may take the form of one or more ventilation holes formed through the outer layer
of the article. The ventilation holes may be located in the cooling segment. The ventilation
region may comprise between one to four rows of ventilation holes.
[0005] WO 2019/096983 A1 describes an apparatus for receiving an article, the article comprising an aerosolisable
material, a mouthpiece and a ventilation region between the proximal end of the article
and the aerosolisable material in a cooling segment. The ventilation region may comprise
a plurality of ventilation holes arranged in two circumferential rows. The apparatus
comprises a housing. The housing contains a heater arrangement to heat the aerosolisable
material. The housing further comprises an opening to allow air to flow into the housing,
the housing may comprise additional air inlets to allow consumable ventilation.
[0006] Typically, an aerosol-generating article is specifically adapted for use in conjunction
with a particular aerosol-generating device or an aerosol-generating device is specifically
adapted for use in conjunction with a particular aerosol-generating article. In particular,
it may be required that certain aerosol-generating articles are not to be used with
a particular aerosol-generating device. This may be because certain articles are suitable
to be heated by the heating element of the particular aerosol-generating device, as
such a device may overheat certain aerosol-generating articles or not heat other aerosol-generating
articles.
[0007] Therefore, it would be desirable to provide an aerosol-generating article that is
adapted to be used in an aerosol-generating system in which the usage of an incompatible
aerosol-generating article with an aerosol-generating device is prevented.
[0008] In the present specification, there is provided an aerosol-generating article for
producing an aerosol upon heating. The aerosol-generating article comprises a rod
of aerosol-forming substrate and a filter positioned downstream of the rod of aerosol-forming
substrate, the filter comprising a hollow tubular segment. The rod of aerosol-forming
substrate and the filter are assembled within a wrapper. The aerosol-generating article
comprises first and second air ingress zones located on the wrapper. The first and
second air ingress zones are each configured to allow the ingress of air into the
interior of the aerosol-generating article. The first air ingress zone is located
along the rod of the aerosol-forming substrate and the second air ingress zone is
located along the hollow tubular segment.
[0009] The second air ingress zone may be located downstream of the first air ingress zone.
[0010] In the present specification, there is provided an aerosol-generating article for
producing an aerosol upon heating. The aerosol-generating article comprises a rod
of aerosol-forming substrate. The aerosol-generating article comprises a downstream
section positioned downstream of the rod of aerosol-forming substrate. The downstream
section comprises a hollow tubular segment. The rod of aerosol-forming substrate and
the downstream section are assembled within a wrapper. The aerosol-generating article
comprises first and second air ingress zones located on the wrapper. The first and
second air ingress zones are each configured to allow the ingress of air into the
interior of the aerosol-generating article. The first air ingress zone is located
along the rod of aerosol-forming substrate. The second air ingress zone is located
along the hollow tubular segment. The second air ingress zone may be located downstream
of the first air ingress zone.
[0011] The aerosol-generating article may comprise an aerosol former. The aerosol-forming
substrate may have an aerosol former content of greater than about 10 percent on a
dry weight basis.
[0012] By providing such a relatively high aerosol former content, this facilitates the
formation of aerosol, particularly, in the context of a heated aerosol-generating
article. The content of aerosol former together with the provision of the first and
second air ingress zones placed at a distance from each other improves the nucleation
of the aerosol, which in turn provides a satisfactory amount of aerosol to be delivered
to a user at the relatively lower temperatures experienced in aerosol-generating articles
that are configured to produce aerosol upon heating, not combusting. In addition,
despite the lower operating temperatures, cooling may still be required downstream
of the aerosol-forming substrate. The provision of a second, downstream air ingress
zone assists with this cooling effect by providing ventilation and the provision of
the aerosol-former enhances the nucleation of the aerosol during use. These improved
aerosol delivery benefits (by improvement in cooling and aerosol nucleation) are further
enhanced where at least one of the air ingress zones is relatively wide (for example,
by comprising a substantially porous portion of the wrapper) or where the aerosol-forming
substrate comprises homogenised tobacco material.
[0013] The filter, or downstream section, comprises a hollow tubular segment. The hollow
tubular segment is located downstream of the rod of aerosol-forming substrate. The
hollow tubular segment may be located immediately downstream of the rod of aerosol-forming
substrate.
[0014] The aerosol-generating article may be configured to be used with a particular aerosol-generating
device to form an aerosol-generating system. The present disclosure also relates to
such an aerosol-generating system. As used herein, the term "aerosol-generating device"
refers to a device comprising a heating element that interacts with the aerosol-forming
substrate of the aerosol-generating article to generate an aerosol.
[0015] The aerosol-generating device of the aerosol-generating system has a distal end and
a mouth end. The aerosol-generating device comprises a housing. The housing defines
a device cavity for removably receiving the aerosol-generating article at the mouth
end of the device. The aerosol-generating device comprises a heater for heating the
aerosol-forming substrate when the aerosol-generating article is received within the
device cavity. The aerosol-generating device comprises an air-flow channel extending
between a channel inlet and a channel outlet. The air-flow channel is configured to
establish a fluid communication between the interior of the device cavity and the
exterior of the aerosol-generating device. The aerosol-generating system is configured
so that, when the aerosol-generating article is received within the device cavity,
fluid communication between the interior of the aerosol-generating article and the
exterior of the aerosol-generating device is established by a fluid communication
being established between the first air ingress zone of the aerosol-generating article
received within the device cavity and the air-flow channel of the aerosol-generating
device.
[0016] In order for an aerosol-generating article of the present invention to be consumed
and generate aerosol within an aerosol-generating device of an aerosol-generating
system, fluid communication between the interior of the aerosol-generating article
and the exterior of the aerosol-generating device must be established. During consumption,
a user may draw on the aerosol-generating article such that aerosol being generating
within the aerosol-generating article can be experienced and consumed by the user.
Through such drawing action, air may flow from the exterior of the aerosol-generating
device, through the aerosol-generating device, and into and through the aerosol-generating
article in order to transport generated aerosol within the article to the mouth of
the user.
[0017] By configuring the aerosol-generating system so that fluid communication between
the interior of the aerosol-generating article and the exterior of the aerosol-generating
device is established by a fluid communication being established between the first
air ingress zone of the aerosol-generating article received within the device cavity
and the air-flow channel of the aerosol-generating device, it is ensured that compatible
aerosol-generating articles are used with the aerosol-generating device. In order
to be used in the aerosol-generating system of the present invention, compatible aerosol-generating
articles are required to have a first air ingress zone configured in such a manner
that a fluid communication is established between the first air ingress zone of the
aerosol-generating article when received within the device cavity and the air-flow
channel of the aerosol-generating device. Further, compatible aerosol-generating devices
are required to have an air-flow channel to be configured in such a manner that it
establishes a fluid communication with the first air ingress zone of an aerosol-generating
article received within the device.
[0018] Fluid communication between the interior of the aerosol-generating article and the
exterior of the aerosol-generating device may be established by an air-flow channel
outlet of the aerosol-generating device overlying, or overlapping, the first air ingress
zone of the aerosol-generating article received within the device cavity. Thus, compatible
aerosol-generating articles are required to have a first air ingress zone configured
in such a manner that an air-flow channel outlet of the aerosol-generating device
overlies, or overlaps, the first air ingress zone of the aerosol-generating article
when received within the device cavity. Further, compatible aerosol-generating devices
are required to have an air-flow channel to be configured in such a manner that an
outlet overlies, or overlaps, the first air ingress zone of an aerosol-generating
article when received within the device.
[0019] If an incompatible aerosol-generating article is used with an aerosol-generating
device of the presently disclosed aerosol-generating system, then the user may not
be able to use the aerosol-generating system and may not be able to consume, or at
least fully experience, the incompatible aerosol-generating article. Further, if a
compatible aerosol-generating article is used with a different aerosol-generating
device not belonging to the aerosol-generating system of the present disclosure, then
the user may also not be able to use the aerosol-generating system and may not be
able to consume, or at least fully experience, the compatible aerosol-generating article.
This is because the fluid communication between the interior of the aerosol-generating
article and the exterior of the aerosol-generating device may not be suitably or fully
established if an alignment of the air-flow channel outlet of the aerosol-generating
device and the first air ingress zone of the aerosol-generating article does not occur.
[0020] The fluid communication between the exterior of the aerosol-generating device and
the interior of the aerosol-generating article may be established by a partial or
complete overlap or alignment between the outlet of the air-flow channel of the device
and the first air ingress zone of the article.
[0021] The fluid communication between the exterior of the aerosol-generating device and
the interior of the aerosol-generating article may be established by a partial or
complete overlap or alignment between the air-flow channel of the device and the first
air ingress zone of the article.
[0022] The first air ingress zone is located at a first position along the rod of aerosol-forming
substrate and the second air ingress zone is located at a second position downstream
of the rod of aerosol-forming substrate.
[0023] By providing a first air ingress zone located at a first position along the rod of
aerosol-forming substrate and a second air ingress zone located at a second position
downstream of the rod of aerosol-forming substrate, the aerosol-generating article
of the present invention can provide both a primary air intake zone along the rod
of aerosol-forming substrate and a ventilation zone downstream of the rod of the aerosol-forming
substrate. During use in a compatible aerosol-generating device, the first air ingress
zone may allow most of the air to enter the aerosol-generating article while the second
air ingress zone may provide ventilation to the aerosol flow being produced in order
to cool the flow and improve a consumer's experience.
[0024] As used herein, the term "longitudinal" refers to the direction corresponding to
the main longitudinal axis of the aerosol-generating article or device, which extends
between the upstream and downstream ends of the aerosol-generating article or aerosol-generating
device.
[0025] As used herein, the terms "upstream" and "downstream" describe the relative positions
of elements, or portions of elements, of the aerosol-generating article or device
in relation to the direction in which the aerosol is transported through the aerosol-generating
article during use.
[0026] The term "mouth end" refers to the portion of an element or component that is configured
to be in, or in the vicinity of, the mouth of a user during normal use of the element
or component. The mouth end of a component may also correspond to a downstream end
of the same component. For example, the mouth end of the aerosol-generating article
may also be the downstream end of the article. The mouth end of the aerosol-generating
article or device is configured to be placed in, or in the vicinity of, the mouth
of a consumer during normal use. The mouth end of the aerosol-generating device may
also be referred to as the proximal end of the aerosol-generating device.
[0027] During use, air is primarily drawn through the aerosol-generating article in the
longitudinal direction. Outside of the device, air may be drawn through the article
via the upstream end.
[0028] The term "transverse" refers to the direction that is perpendicular to the longitudinal
axis. Any reference to the "cross-section" of the aerosol-generating article or a
component of the aerosol-generating article refers to the transverse cross-section
unless stated otherwise.
[0029] The term "length" denotes the dimension of a component of the aerosol-generating
article or device with reference to the longitudinal direction.
[0030] The device cavity may be referred to as the heating chamber of the aerosol-generating
device. The device cavity may extend between a distal end and a mouth, or proximal,
end. The distal end of the device cavity may be a closed end and the mouth, or proximal,
end of the device cavity may be an open end. An aerosol-generating article may be
inserted into the device cavity, or heating chamber, via the open end of the device
cavity. The device cavity may be cylindrical in shape so as to conform to the same
shape of an aerosol-generating article.
[0031] The expression "received within" may refer to the fact that a component or element
is fully or partially received within another component or element. For example, the
expression "aerosol-generating article is received within the device cavity" refers
to the aerosol-generating article being fully or partially received within the device
cavity of the aerosol-generating article. When the aerosol-generating article is received
within the device cavity, the aerosol-generating article may abut the distal end of
the device cavity. When the aerosol-generating article is received within the device
cavity, the aerosol-generating article may be in substantial proximity to the distal
end of the device cavity. The distal end of the device cavity may be defined by an
end-wall.
[0032] The length of the device cavity may be between about 10 mm and about 50 mm. The length
of the device cavity may be between about 20 mm and about 40 mm. The length of the
device cavity may be between about 25 mm and about 30 mm. The length of the device
cavity may be the same as or greater than the length of the rod of the aerosol-forming
substrate.
[0033] A diameter of the device cavity may be between about 4 mm and about 50 mm. A diameter
of the device cavity may be between about 4 mm and about 30 mm. A diameter of the
device cavity may be between about 5 mm and about 15 mm. A diameter of the device
cavity may be between about 6 mm and about 12 mm. A diameter of the device cavity
may be between about 7 mm and about 10 mm. A diameter of the device cavity may be
between about 7 mm and about 8 mm.
[0034] A diameter of the device cavity may be the same as or greater than a diameter of
the aerosol-generating article. A diameter of the device cavity may be the same as
a diameter of the aerosol-generating article in order to establish a tight fit with
the aerosol-generating article.
[0035] The device cavity may be configured to establish a tight fit with an aerosol-generating
article received within the device cavity. Tight fit may refer to a snug fit. The
aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may
define the device cavity, or heating chamber. The peripheral wall defining the device
cavity may be configured to engage with an aerosol-generating article received within
the device cavity in a tight fit manner, so that there is substantially no gap or
empty space between the peripheral wall defining the device cavity and the aerosol-generating
article when received within the device.
[0036] Such a tight fit may establish an airtight fit or configuration between the device
cavity and an aerosol-generating article received therein. Such an airtight configuration
may mean that air can only be drawn into the interior of the aerosol-generating article
through the alignment or overlap of the air-flow channel outlet and the first air
ingress zone. With such an airtight configuration, there would be substantially no
gap or empty space between the peripheral wall defining the device cavity and the
aerosol-generating article for air to flow through. Therefore, when an incompatible
aerosol-generating article is used with the aerosol-generating device, such an alignment
may not occur and therefore air may not be drawn through the incompatible aerosol-generating
article.
[0037] The tight fit with an aerosol-generating article may be established along the entire
length of the device cavity or along a portion of the length of the device cavity.
The tight fit may be established at a position downstream of the first air ingress
zone of the aerosol-generating article. The portion of the peripheral wall that is
configured to establish such a tight fit may be referred to as the sealing portion
of the peripheral wall. Such a tight fit may be established when the air-flow channel
is defined within the thickness of the peripheral wall of the aerosol-generating device.
The sealing portion of the peripheral wall may be defined along the whole length of
the device cavity.
[0038] When the air-flow channel is defined on the inner surface of the peripheral wall
of the device housing, a portion of the peripheral wall between the air-flow channel
and the distal end of the device cavity may define the sealing portion of the peripheral
wall. This will ensure that air may not flow beyond the air-flow channel towards the
upstream end of the aerosol-generating article. The portion of the peripheral wall
between the air-flow channel and the distal end of the device cavity may form an airtight
configuration with an upstream portion of the aerosol-generating article, when received
within the device.
[0039] The sealing portion of the peripheral wall may be configured to establish an airtight
fit with a portion of the aerosol-generating article at a position downstream of the
first air ingress zone of the aerosol-generating article. The sealing portion of the
peripheral wall may be configured to establish an airtight fit with a portion of the
aerosol-generating article at a position downstream of a second air ingress zone of
the aerosol-generating article.
[0040] The diameter of the device cavity may vary along the longitudinal direction of the
aerosol-generating device. The diameter of the device cavity may decrease from the
distal end of the device cavity to the sealing portion of the peripheral wall.
[0041] The diameter of the device cavity may increase from the sealing portion of the peripheral
wall in a direction towards the distal end of the device cavity. The diameter of the
device cavity between the distal end of the device cavity and the sealing portion
of the peripheral wall may be greater than the diameter of the rest of the device
cavity. The diameter of the device cavity may increase in a direction away from the
sealing portion of the peripheral wall and away from the mouth end of the device.
[0042] By providing a portion of the device cavity with a greater diameter or greater diameters
than the rest of the device cavity, the device cavity may define gap or chamber around
(surrounding) an upstream portion of the aerosol-generating article when received
within the device. In such embodiments, alignment or overlap between the first air
ingress zone and the first outlet of the air-flow channel of the device may not be
necessary to ensure fluid communication between the exterior of the device and the
interior of the article. Air flow will still need to be admitted into the article
via the first air ingress zone. Air flowing into the device cavity via the first outlet
of the air-flow channel may flow into such gap or chamber and then be drawn into the
article via the first air ingress zone. Such gap or chamber may provide a cushion
of air around said upstream portion of the article, which could either be heated by
the heater of the device or act as a cushion of cooling air surrounding the article.
[0043] The aerosol-generating device may comprise a peripheral wall defining the device
cavity and the aerosol-generating device may comprise a circumferential protrusion
extending from the peripheral wall into the device cavity, the circumferential protrusion
being configured to establish an airtight fit with a portion of the aerosol-generating
article, when received within the aerosol-generating device, at a position downstream
of the first air ingress zone of the aerosol-generating article.
[0044] The diameter of the device cavity may be greater than the diameter of the aerosol-generating
article and the inner diameter of the circumferential protrusion may be the same as
the diameter of the aerosol-generating article such that a tight fit is established
between the article and the circumferential protrusion once the article is received
within the aerosol-generating device. The inner diameter of the circumferential protrusion
may even be smaller than the diameter of the aerosol-generating article. This may
ensure that an airtight fit is more reliably established.
[0045] By establishing an airtight fit with the aerosol-generating article downstream of
the first air ingress zone, it is further ensured that air can only enter the interior
of the aerosol-generating article through the alignment of the air-flow channel outlet
and the first air ingress zone. This may be achieved either by the sealing portion
of the peripheral wall or the circumferential protrusion, both of which are described
above.
[0046] When the aerosol-generating article is received within the device cavity, the upstream
end of the aerosol-generating article may be blocked such that air is substantially
prevented from entering the aerosol-generating article through its upstream end. However,
when the aerosol-generating article is not received within the aerosol-generating
device, air may flow through the aerosol-generating article through its upstream end.
When the article is received or inserted into the device, the upstream end of the
aerosol-generating article may about the distal end of the device cavity such that
air may no longer be able to flow through the upstream end of the article. As such,
the air flowing through the air-flow channel may only be able to be drawn through
the article via the first air ingress zone. The upstream end of the aerosol-generating
article may be defined by the upstream end of the rod of aerosol-forming substrate.
[0047] The air-flow channel of the aerosol-generating device may be defined within the housing
of the aerosol-generating device to enable fluid communication between the interior
of the device cavity and the exterior of the aerosol-generating device. When an aerosol-generating
article is received within the device cavity, the air-flow channel may be configured
to provide air flow into the article in order to deliver generated aerosol to a user
drawing from the mouth end of the article.
[0048] The air-flow channel of the aerosol-generating device may be defined within, or by,
the peripheral wall of the housing of the aerosol-generating device. In other words,
the air-flow channel of the aerosol-generating device may be defined within the thickness
of the peripheral wall or by the inner surface of the peripheral wall, or a combination
of both. The air-flow channel may partially be defined by the inner surface of the
peripheral wall and may be partially defined within the thickness of the peripheral
wall. The inner surface of the peripheral wall defines a peripheral boundary of the
device cavity.
[0049] The air-flow channel of the aerosol-generating device may extend from an inlet located
at the mouth end, or proximal end, of the aerosol-generating device to an outlet located
away from mouth end of the device. The air-flow channel may extend along a direction
parallel to the longitudinal axis of the aerosol-generating device. The outlet of
the air-flow channel is configured such that, when a compatible aerosol-generating
article is received within the device cavity, the outlet overlies the first air ingress
zone of the article.
[0050] The air-flow channel may be provided with more than one outlet, one for each air
ingress zone provided in an article configured to be used with the aerosol-generating
device. For example, if an aerosol-generating article comprises a first air ingress
zone and a second air ingress zone, then the air-flow channel of a corresponding aerosol-generating
device may have at least one first outlet for overlying the first air ingress zone
and at least one second outlet for overlying the second air ingress zone when the
aerosol-generating article is fully received within the aerosol-generating device.
Thus, the aerosol-generating system may be configured so that, when the aerosol-generating
article is received within the device cavity, fluid communication between the interior
of the aerosol-generating article and the exterior of the aerosol-generating device
is established by a fluid communication being established between the first and second
air ingress zones of the aerosol-generating article received within the device cavity
and the air-flow channel of the aerosol-generating device.
[0051] When the air-flow channel is defined within the peripheral wall of the device, the
air-flow channel may comprise a first portion extending in the axial direction of
device from a channel inlet and a second portion extending in the transverse, or radial,
direction from the end of the first portion to a channel outlet. As a result, the
air-flow channel may comprise a bend or elbow in order to connect the inlet and outlet
of the air-flow channel. If the air-flow channel comprises more than one outlet along
its length, the air-flow channel may comprise further channel portions extending in
a transverse direction from the first portion to each of the further outlets. Where
an air-flow channel comprises a single outlet, the air-flow channel may comprise an
L-shaped bend or elbow.
[0052] When the air-flow channel is defined by the inner surface of the peripheral wall,
a length of the air-flow channel may be exposed directly to the device cavity, that
is, a longitudinal side of the air-flow channel may be open to the device cavity.
The thickness of the portion of the peripheral wall defining the air-flow channel
may be less than the thickness of the rest of the peripheral wall. The diameter of
the portion of the peripheral wall defining the air-flow channel may be greater than
the diameter of the rest of the peripheral wall. In such embodiments, the air-flow
channel may be annular in shape such that the air-flow channel circumscribes the device
cavity and an aerosol-generating article received within the device cavity.
[0053] In embodiments where the air-flow channel is defined by the inner surface of the
peripheral wall of the housing, the entire length of the air-flow channel may be exposed
or open to the device cavity and thus to an aerosol-generating article received within
the device. In such embodiments, in order to establish a fluid communication between
the exterior of the aerosol-generating device and the interior of the aerosol-generating
article, the air-flow channel is configured to overlie all air ingress zones of a
compatible aerosol-generating article. In such embodiments, an outlet of the air-flow
channel may be considered the open side of the air-flow channel; that is, the side
of the air-flow channel exposed or opened to the device cavity.
[0054] The length of the air-flow channel may be less than the length of the device cavity.
The length of the air-flow channel refers to the longitudinal or axial distance by
which the air-flow channel extends.
[0055] The air-flow channel may be configured such that a first outlet of the air-flow channel
is arranged to align with or overlie the first air ingress zone of an aerosol-generating
article received within the device cavity. The air-flow channel may extend from a
first inlet located at the mouth end of the housing of the aerosol-generating device
to the first outlet. The first, or any, outlet of the air-flow channel may be provided
between the distal end and mouth end of the device cavity.
[0056] The first outlet may be located at least about 2 mm away from the distal end of the
device cavity. The first outlet may be located at least about 3 mm away from the distal
end of the device cavity. The first outlet may be located at least about 5 mm away
from the distal end of the device cavity. The first outlet may be located at least
about 7 mm away from the distal end of the device cavity.
[0057] A distance of the first outlet from the distal end of the device cavity and a distance
of the first air ingress zone, when the article is received within the device cavity,
from the distal end of the device cavity may be similar or the same. A distance of
a further outlet of the air-flow channel from the distal end of the device cavity
and a distance of a further air ingress zone, when the article is received within
the device cavity, from the distal end of the device cavity may be similar or the
same. A distance of a distal end of the air-flow channel from the distal end of the
device cavity and a distance of an air ingress zone, when the article is received
within the device cavity, from the distal end of the device cavity may be similar
or the same.
[0058] The first outlet may be located no more than about 25 mm away from the distal end
of the device cavity. The first outlet may be located between about 3 mm and about
20 mm away from the distal end of the device cavity. The first outlet may be located
between about 5 mm and about 18 mm away from the distal end of the device cavity.
The first outlet may be located between about 7 mm and about 16 mm away from the distal
end of the device cavity. The air-flow channel may not extend beyond the distal end
of the device cavity.
[0059] The length of the air-flow channel may be about 23 mm. The length of the air-flow
channel may be between about 3 mm and about 100 mm. The length of the air-flow channel
may be between about 8 mm and about 70 mm. The length of the air-flow channel may
be between about 10 mm and about 50 mm. The length of the air-flow channel may be
between about 12 mm and about 40 mm. The length of the air-flow channel may be between
about 12 mm and about 40 mm. The length of the air-flow channel may be between about
15 mm and about 30 mm. The length of the air-flow channel may be between about 20
mm and about 25 mm.
[0060] If a compatible aerosol-generating article comprises a first air ingress zone located
downstream of the rod of aerosol-forming substrate, the length of the air-flow channel
may be between about 8 mm and about 25 mm. The length of the air-flow channel may
be between about 10 mm and about 15 mm. The length of the air-flow channel may be
between about 11 mm and about 13 mm.
[0061] The diameter of the air-flow channel may be between about 0.1 mm and about 5 mm.
The diameter of the air-flow channel may be about 0.5 mm and about 4 mm. The diameter
of the air-flow channel may be about 1 mm and about 3 mm. The diameter of the air-flow
channel may be about 1.5 mm and about 2.5 mm. The diameters of the air-flow channel
and its outlets and inlets may be the same or different.
[0062] The 'length' of the air-flow channel may refer to how much the air-flow channel extends
in the longitudinal direction.
[0063] There may be a plurality of air-flow channels provided in the aerosol-generating
device, each having at least one inlet and at least one outlet. Such a plurality of
air-flow channels may be evenly and circumferentially distributed around the device
cavity.
[0064] A, or each, air-flow channel may comprise a single inlet and multiple outlets. In
such embodiments, there may be one outlet corresponding to each air ingress zone provided
on an aerosol-generating article configured to be received within the aerosol-generating
device.
[0065] As discussed above, an aerosol-generating article in accordance with the present
invention comprises a rod of aerosol-forming substrate and filter, or downstream section,
located downstream of the rod of aerosol-forming substrate.
[0066] The aerosol-generating article may further comprise an upstream section at a location
upstream of the rod of aerosol-generating substrate. The upstream section may comprise
one or more upstream elements. In some embodiments, the upstream section may comprise
an upstream element arranged immediately upstream of the aerosol-generating element.
The upstream element may extend from an upstream end of the aerosol-generating substrate
to the upstream end of the aerosol-generating article. The upstream element may abut
the upstream end of the aerosol-generating article. The upstream element may be referred
to as an upstream section. The aerosol-generating article may comprise an air inlet
at the upstream end of the aerosol-generating article. Where the aerosol-generating
article comprises an upstream element, the air inlet may be provided through the upstream
element. The air entering through the air inlet may pass into the aerosol-generating
substrate in order to generate the mainstream aerosol.
[0067] The porosity or permeability of the upstream section may advantageously be varied
in order to provide a desirable overall resistance to draw of the aerosol-generating
article.
[0068] In some embodiments, the upstream section may be formed from a material that is impermeable
to air. In such embodiments, the aerosol-generating article may be configured such
that air flows into the rod of aerosol-generating substrate through suitable ventilation
means provided in a wrapper.
[0069] The upstream section may be made of any material suitable for use in an aerosol-generating
article. For example, the upstream element may comprise a plug of material. Suitable
materials for forming the upstream section include filter materials, ceramic, polymer
material, cellulose acetate, cardboard, zeolite or aerosol-generating substrate. Preferably,
the upstream section comprises a plug comprising cellulose acetate.
[0070] Where the upstream section comprises a plug of material, the downstream end of the
plug of material may about the upstream end of the aerosol-generating substrate. For
example, the upstream section may comprise a plug comprising cellulose acetate abutting
the upstream end of the aerosol-generating substrate. This may advantageously help
retain the aerosol-generating substrate in place.
[0071] Where the upstream section comprises a plug of material, the downstream end of the
plug of material may be spaced apart from the upstream end of the aerosol-generating
substrate. The upstream element may comprise a plug comprising fibrous filtration
material.
[0072] The upstream section may have a length of at least about 1 millimetre. For example,
the upstream section may have a length of at least about 2 millimetres, at least about
4 millimetres, or at least about 6 millimetres.
[0073] The upstream section may have a length of no more than about 15 millimetres. For
example, the upstream section may have a length of no more than about 12 millimetres,
no more than about 10 millimetres, or no more than about 8 millimetres.
[0074] The upstream section may have a length of between about 1 millimetre and about 15
millimetres. For example, the upstream section may have a length of between about
2 millimetres and about 12 millimetres, between about 4 millimetres and about 10 millimetres,
or between about 6 millimetres and about 8 millimetres.
[0075] The upstream section or element may comprise a hollow tubular segment.
[0076] The filter, or downstream section, may comprise a mouthpiece segment comprising a
plug of filtration material, and the hollow tubular segment may be at a location between
the rod of aerosol-forming substrate and the mouthpiece segment. All three elements
may be longitudinally aligned. The rod of aerosol-forming substrate may comprise at
least an aerosol former. The hollow tubular segment may be a support segment or a
cooling segment. The hollow tubular segment may be positioned or located immediately
downstream of the aerosol-forming substrate.
[0077] The filter or downstream section may comprise a mouthpiece segment comprising a plug
of filtration material, and an aerosol-cooling segment (or element) at a location
between the rod of aerosol-forming substrate and the mouthpiece segment. All three
elements may be longitudinally aligned.
[0078] The mouthpiece segment may comprise a hollow tubular segment. The mouthpiece segment
may be a hollow tubular segment. The mouthpiece segment may be a plug of filtration
material.
[0079] As used herein, an 'aerosol-cooling element' may refer to a component of an aerosol-generating
article located downstream of the aerosol-forming substrate such that, in use, an
aerosol formed by volatile compounds released from the aerosol-forming substrate passes
through and is cooled by the aerosol cooling element before being inhaled by a user.
An aerosol cooling element has a large surface area, but causes a low pressure drop.
The aerosol-cooling element may act to cool the temperature of a stream of aerosol
drawn through the element by means of thermal transfer. Components of the aerosol
will interact with the aerosol-cooling element and loose thermal energy.
[0080] The aerosol-cooling element may comprise a sheet material selected from the group
comprising a metallic foil, a polymeric sheet, and a substantially non-porous paper
or cardboard. In some embodiments, the aerosol-cooling element may comprise a sheet
material selected from the group consisting of polyethylene (PE), polypropylene (PP),
polyvinylchloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA),
cellulose acetate (CA), and aluminium foil.
[0081] After consumption, aerosol-generating articles are typically disposed of. It may
be advantageous for the elements forming the aerosol-generating article to be biodegradable.
Thus, it may be advantageous for the aerosol-cooling element to be formed from a biodegradable
material, for example a non-porous paper or a biodegradable polymer such as polylactic
acid or a grade of Mater-Bi
® (a commercially available family of starch based copolyesters). In some embodiments,
the entire aerosol-generating article is biodegradable or compostable.
[0082] In some embodiments, an aerosol-generating article in accordance with the invention
may comprise an additional support element (or support segment) arranged between,
and in longitudinal alignment with, the rod of aerosol-forming substrate and, the
hollow tubular segment or the aerosol-cooling segment (or element). In more detail,
the support element (or support segment) may be provided immediately downstream of
the rod and immediately upstream of the hollow tubular segment or the aerosol-cooling
element. The additional support element or segment may be tubular.
[0083] The wrapper of the aerosol-generating article may comprise an air-impermeable material.
The wrapper of the aerosol-generating article may comprise an air-impervious material.
By providing the aerosol-generating article with an air-impermeable or air-impervious
material, when the upstream end of the aerosol-generating article is blocked upon
insertion into the device cavity, or heating chamber, of the aerosol-generating device,
it is ensured that air has to be drawn through the first air ingress zone in order
for air to enter the aerosol-generating article. In other words, it is ensured that
the first air ingress zone may define the primary, and only, air intake portion of
the article through which air can be drawn through into the article.
[0084] The expression "air-impervious material" or "air-impermeable material" is used throughout
this specification to mean a material substantially not allowing the passage of fluids,
particularly air and smoke, through interstices or pores in the material. If, for
example, the wrapper is formed of a material impervious to air and aerosol particles,
air and aerosol particles drawn through the article cannot flow across the material
of the wrapper. By contrast, the term "porous" is used herein to refer to a material
that provides a plurality of pores or openings that allow the passage of air through
the material.
[0085] By providing a wrapper with an air-impermeable material, air may only access the
interior of the aerosol-generating article via the first air ingress zone provided
in the wrapper when the article is received within the aerosol-generating device.
[0086] The first air ingress zone may be located around the rod of aerosol-forming substrate.
[0087] The support segment may be a hollow support segment.
[0088] The aerosol-generating article may extend between an upstream end and a downstream
end. The downstream end of the article may coincide with the downstream end of the
rod of aerosol-forming substrate. In other words, the downstream end of the rod of
aerosol-forming substrate may define a downstream end of the aerosol-generating article.
[0089] The first air ingress zone may be located at least about 2 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
at least about 3 mm downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located at least about 4 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
at least about 5 mm downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located at least about 6 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
at least about 7 mm downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located at least about 8 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
at least about 9 mm downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located at least about 10 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
at least about 12 mm downstream of the upstream end of the rod of aerosol-forming
substrate.
[0090] The first air ingress zone may be located about 20 mm or less downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
about 15 mm or less downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located about 14 mm or less downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
about 13 mm or less downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located about 12 mm or less downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
about 10 mm or less downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located about 9 mm or less downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
about 8 mm or less downstream of the upstream end of the rod of aerosol-forming substrate.
The first air ingress zone may be located about 6 mm or less downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
about 5 mm or less downstream of the upstream end of the rod of aerosol-forming substrate.
[0091] The first air ingress zone may be located between about 2 mm and about 20 mm downstream
of the upstream end of the rod of aerosol-forming substrate. The first air ingress
zone may be located between about 3 mm and about 15 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
between about 4 mm and about 12 mm downstream of the upstream end of the rod of aerosol-forming
substrate.
[0092] The first air ingress zone may be located between about 2 mm and about 15 mm downstream
of the upstream end of the rod of aerosol-forming substrate. The first air ingress
zone may be located between about 3 mm and about 12 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
between about 5 mm and about 10 mm downstream of the upstream end of the rod of aerosol-forming
substrate.
[0093] The first air ingress zone may be located between about 2 mm and about 12 mm downstream
of the upstream end of the rod of aerosol-forming substrate. The first air ingress
zone may be located between about 3 mm and about 10 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The first air ingress zone may be located
between about 5 mm and about 8 mm downstream of the upstream end of the rod of aerosol-forming
substrate.
[0094] The first air ingress zone may be located between about 2 mm and about 10 mm downstream
of the upstream end of the rod of aerosol-forming substrate. The first air ingress
zone may be located between about 3 mm and about 9 mm downstream of the upstream end
of the rod of aerosol-forming substrate. The first air ingress zone may be located
between about 5 mm and about 8 mm downstream of the upstream end of the rod of aerosol-forming
substrate.
[0095] The first air ingress zone may be located between about 2 mm and about 8 mm downstream
of the upstream end of the rod of aerosol-forming substrate. The first air ingress
zone may be located between about 2 mm and about 6 mm downstream of the upstream end
of the rod of aerosol-forming substrate. The first air ingress zone may be located
between about 2 mm and about 5 mm downstream of the upstream end of the rod of aerosol-forming
substrate.
[0096] The first air ingress zone may be located between about 10 mm and about 20 mm downstream
of the upstream end of the rod of aerosol-forming substrate. The first air ingress
zone may be located between about 12 mm and about 15 mm downstream of the upstream
end of the rod of aerosol-forming substrate.
[0097] The first air ingress zone may be located along the upstream half of the rod of aerosol-forming
substrate. By positioning the first air ingress zone along the upstream half of the
rod of aerosol-forming substrate, air being drawn through the first air ingress zone
may be drawn through a substantial length of the rod of aerosol-forming substrate
in order to optimise aerosol generation and efficiently use the aerosol-forming substrate.
[0098] The first air ingress zone may be located along the downstream half of the rod of
aerosol-forming substrate.
[0099] Throughout this specification, where it is stated that the air ingress zone is or
may be located along a certain component of the aerosol-generating article, this refers
to the fact that the air ingress zone is located on a portion of the wrapper that
overlies such a component of the aerosol-generating article. For example, if the air
ingress zone is located along the rod of aerosol-forming substrate, this refers to
the fact that the air ingress zone is located on a portion of the wrapper that overlies
the rod of aerosol-forming substrate.
[0100] The term "upstream half" refers to the region or portion of an element between the
upstream end of the element and the midpoint of the element. The term "downstream
half" refers to the region or portion of an element between the downstream end of
the element and the midpoint of the element.
[0101] The aerosol-generating article may be provided with additional air ingress zones
to provide additional functionality to the first air ingress zone. The aerosol-generating
article comprises a second air ingress zone located on the wrapper. Such a second
air ingress zone may be configured to provide ventilation to the aerosol-generating
article during use within the device as a ventilation zone, while the first air ingress
zone serves as an air intake zone of the article. Further, air ingress zones may be
provided so as to provide further ventilation to the article during normal, and compatible,
use.
[0102] The second air ingress zone is located along the filter or downstream section of
the aerosol-generating article.
[0103] The second air ingress zone may be located at least about 1 mm downstream of the
rod of aerosol-forming substrate. That is, the second air ingress zone may be located
at least 1 mm downstream of the downstream end of the rod of aerosol-forming substrate.
The second air ingress zone may be located at least about 2 mm downstream of the rod
of aerosol-forming substrate. The second air ingress zone may be located at least
about 3 mm downstream of the rod of aerosol-forming substrate.
[0104] The second air ingress zone may be located about 8 mm or less downstream of the rod
of aerosol-forming substrate. The second air ingress zone may be located about 7 mm
or less downstream of the rod of aerosol-forming substrate. The second air ingress
zone may be located about 6 mm or less downstream of the rod of aerosol-forming substrate.
[0105] The second air ingress zone may be located between about 1 mm and about 8 mm downstream
of the rod of aerosol-forming substrate. The second air ingress zone may be located
between about 2 mm and about 7 mm downstream of the rod of aerosol-forming substrate.
The second air ingress zone may be located between about 2 mm and about 6 mm downstream
of the rod of aerosol-forming substrate. The second air ingress zone may be located
between about 3 mm and about 6 mm downstream of the rod of aerosol-forming substrate.
[0106] The second air ingress zone may be located at least about 1 mm downstream of the
upstream end of the hollow tubular segment. The second air ingress zone may be located
at least about 2 mm downstream of the upstream end of the hollow tubular segment.
The second air ingress zone may be located at least about 3 mm downstream of the upstream
end of the hollow tubular segment.
[0107] The second air ingress zone may be located about 8 mm or less downstream of the upstream
end of the hollow tubular segment. The second air ingress zone may be located about
7 mm or less downstream of the upstream end of the hollow tubular segment. The second
air ingress zone may be located about 6 mm or less downstream of the upstream end
of the hollow tubular segment.
[0108] The second air ingress zone may be located between about 1 mm and about 8 mm downstream
of the upstream end of the hollow tubular segment. The second air ingress zone may
be located between about 2 mm and about 7 mm downstream of the upstream end of the
hollow tubular segment. The second air ingress zone may be located between about 2
mm and about 6 mm downstream of the upstream end of the hollow tubular segment. The
second air ingress zone may be located between about 3 mm and about 6 mm downstream
of the upstream end of the hollow tubular segment.
[0109] The second air ingress zone may be located at least about 1 mm downstream of the
upstream end of the support segment. The second air ingress zone may be located at
least about 2 mm downstream of the upstream end of the support segment. The second
air ingress zone may be located at least about 3 mm downstream of the upstream end
of the support segment.
[0110] The second air ingress zone may be located about 8 mm or less downstream of the upstream
end of the support segment. The second air ingress zone may be located about 7 mm
or less downstream of the upstream end of the support segment. The second air ingress
zone may be located about 6 mm or less downstream of the upstream end of the support
segment.
[0111] The second air ingress zone may be located between about 1 mm and about 8 mm downstream
of the upstream end of the support segment. The second air ingress zone may be located
between about 2 mm and about 7 mm downstream of the upstream end of the support segment.
The second air ingress zone may be located between about 2 mm and about 6 mm downstream
of the upstream end of the support segment. The second air ingress zone may be located
between about 3 mm and about 6 mm downstream of the upstream end of the support segment.
[0112] The second air ingress zone may be located at least about 3.5 mm downstream of the
upstream end of the rod of aerosol-forming substrate. The second air ingress zone
may be located at least about 4 mm downstream of the upstream end of the rod of aerosol-forming
substrate. The second air ingress zone may be located at least about 6.5 mm downstream
of the upstream end of the rod of aerosol-forming substrate.
[0113] The second air ingress zone may be located about 20 mm or less downstream of the
upstream end of the rod of aerosol-forming substrate. The second air ingress zone
may be located about 16 mm or less downstream of the upstream end of the rod of aerosol-forming
substrate. The second air ingress zone may be located about 12 mm or less downstream
of the upstream end of the rod of aerosol-forming substrate.
[0114] The second air ingress zone may be located between about 3.5 mm and about 20 mm downstream
of the upstream end of the rod of aerosol-forming substrate. The second air ingress
zone may be located between about 4 mm and about 16 mm downstream of the upstream
end of the rod of aerosol-forming substrate. The second air ingress zone may be located
between about 6.5 mm and about 12 mm downstream of the upstream end of the rod of
aerosol-forming substrate.
[0115] The second air ingress zone may be located at least about 1.5 mm downstream of the
first air ingress zone. The second air ingress zone may be located at least about
2 mm downstream of the first air ingress zone. The second air ingress zone may be
located at least about 3 mm downstream of the first air ingress zone.
[0116] The second air ingress zone may be located at least about 10 mm downstream of the
first air ingress zone. The second air ingress zone may be located at least about
12 mm downstream of the first air ingress zone. In such embodiments, the second air
ingress zone may be located downstream of the rod of aerosol-forming substrate.
[0117] The second air ingress zone may be located about 20 mm or less downstream of the
first air ingress zone. The second air ingress zone may be located about 18 mm or
less downstream of the first air ingress zone. The second air ingress zone may be
located about 16 mm or less downstream of the first air ingress zone.
[0118] The second air ingress zone may be located between about 1.5 mm and about 20 mm downstream
of the first air ingress zone. The second air ingress zone may be located between
about 2 mm and about 18 mm downstream of the first air ingress zone. The second air
ingress zone may be located between about 3 mm and about 16 mm downstream of the first
air ingress zone.
[0119] The second air ingress zone may be located along the upstream half of the hollow
tubular segment. The second air ingress zone may be located along the upstream half
of the support segment. The second air ingress zone may be located along the downstream
half of the hollow tubular segment. The second air ingress zone may be located along
the downstream half of the support segment.
[0120] An air ingress zone may comprise one or more rows of apertures, or perforations,
extending through the wrapper of the aerosol-generating article. The apertures, or
perforations, of an air ingress zone may extend through the filter or downstream section
of the aerosol-generating article. The apertures, or perforations, of an air ingress
zone may extend through the peripheral wall of the hollow tubular segment of the article.
The apertures, or perforations, of the air ingress zone may extend through the peripheral
wall of the support segment of the article, particularly if the support segment is
hollow.
[0121] An air ingress zone may comprise only one row of apertures or perforations. A row
of apertures, or perforations, may comprise between 8 to 30 apertures or perforations.
A row of apertures, or perforations, may comprise between 10 to 20 apertures or perforations.
The air ingress zone may circumscribe the aerosol-generating article. The air ingress
zone may circumscribe the rod of aerosol-forming substrate. The air ingress zone may
circumscribe the hollow tubular segment. The air ingress zone may circumscribe the
support segment.
[0122] The perforations of an air ingress zone may be of uniform size. As an alternative,
the perforations may vary in size. By varying the number and size of the perforations,
it is possible to adjust the amount of external air admitted into the hollow tubular
segment when the consumer draws on the mouthpiece of the aerosol-generating article
during use. As such, it is advantageously possible to adjust the ventilation or air
intake level of the aerosol-generating article. Preferably, the perforations are round.
[0123] The air ingress perforations can be formed using any suitable technique, for example
by laser technology, mechanical perforation of the hollow tubular segment or support
segment as part of the aerosol-generating article or pre-perforation of the hollow
tubular segment or support segment before it is combined with the other elements to
form the aerosol-generating article. Preferably, the perforations are formed by online
laser perforation.
[0124] In addition, the inventors have found that in aerosol-generating articles in accordance
with the invention the cooling and diluting effect caused by the admission of ventilation
air at the location along the conduit defined by the hollow tubular segment described
above has a surprising reducing effect on the generation and delivery of phenol-containing
species.
[0125] The air ingress or ventilation zone may comprise one or more rows of perforations
formed through the peripheral wall of the hollow tubular segment. As discussed above,
the second air ingress zone may be a ventilation zone. Preferably, the ventilation
zone comprises only one row of perforations. This is understood to be advantageous
in that, by concentrating the cooling effect brought about by ventilation over a short
portion of the cavity defined by the hollow tube segment, it may be possible to further
enhance aerosol nucleation. This is because a faster and more drastic cooling of the
stream of volatilised species is expected to particularly favour the formation of
new nuclei of aerosol particles.
[0126] Preferably, the one or more rows of perforations are arranged circumferentially around
the wall of the hollow tube. Where the ventilation zone comprises two or more rows
of perforations formed through the peripheral wall of the hollow tubular segment,
the rows are longitudinally spaced apart from one another along the hollow tubular
segment.
[0127] The radius of the air ingress perforations, or apertures, may be at least about 0.05
mm. The radius of the air ingress perforations, or apertures, may be at least about
0.06 mm. The radius of the air ingress perforations, or apertures, may be at least
about 0.1 mm. The radius of the air ingress perforations may be between about 0.06
mm and about 0.1 mm.
[0128] An equivalent diameter of at least one of the ventilation or air ingress perforations
is preferably at least about 100 micrometres. Preferably, an equivalent diameter of
at least one of the ventilation perforations is at least about 150 micrometres. Even
more preferably, an equivalent diameter of at least one of the ventilation perforations
is at least about 200 micrometres. In addition, or as an alternative, an equivalent
diameter of at least one of the ventilation perforations is preferably less than about
500 micrometres. More preferably, an equivalent diameter of at least one of the ventilation
perforations is less than about 450 micrometres. Even more preferably, an equivalent
diameter of at least one of the ventilation perforations is less than about 400 micrometres.
The term "equivalent diameter" is used herein to denote the diameter of a circle having
the same surface area of a cross-section of the ventilation perforation. A cross-section
of the ventilation perforations may have any suitable shape. However, circular ventilation
perforations are preferred.
[0129] The ventilation or air ingress perforations may be of uniform size. As an alternative,
the ventilation perforations may vary in size. By varying the number and size of the
ventilation perforations, it is possible to adjust the amount of external air admitted
into the hollow tubular segment when the consumer draws on the mouthpiece of the aerosol-generating
article during use. As such, it is advantageously possible to adjust the ventilation
level of the aerosol-generating article.
[0130] An air ingress zone may comprise a substantially porous portion of the wrapper of
the aerosol-generating article. Such a porous portion may be defined in the air-impervious
or air-impermeable wrapper of the aerosol-generating article or may be defined by
a different material forming part of the wrapper of the aerosol-generating article.
Such a porous portion may be defined by a porous pattern defined in the wrapper. Such
a porous portion may define the first or second air ingress zone. As such, the first
or second air ingress zone may have the porosity characteristics of such a porous
portion.
[0131] Such a porous portion of the wrapper may have a relatively high porosity, in relation
to the rest of the wrapper of the aerosol-generating article. The porosity of such
a porous portion may be at least about 3000 Coresta Units (CU). The porosity of such
a porous portion may be at least about 5000 Coresta Units (CU). The porosity of such
a porous portion may be less than about 25000 Coresta Units (CU). The porosity of
such a porous portion may be less than about 20000 Coresta Units (CU). The porosity
of such a porous portion may be between about 3000 CU and about 25000 CU. The porosity
of such a porous portion may be between about 5000 CU and about 20000 CU.
[0132] The width of an air ingress zone (a first, second or any air ingress zone) may be
at least about 1 mm. The width of an air ingress zone may be at least about 3 mm.
The width of an air ingress zone may be at least about 5 mm. The 'width' of an air
ingress zone refers to the sizing of an air ingress zone in the axial or longitudinal
direction of the aerosol-generating article. This, the 'width' of an air ingress zone
may be referred to as a 'length' of the air ingress zone.
[0133] The width of the first air ingress zone may be greater than the width of the second
air ingress zone. This enables the first air ingress zone to serve its function as
the primary air intake of the aerosol-generating article when received within a compatible
aerosol-generating device, while the second or subsequent air ingress zone may serve
as secondary air intake zones or ventilation zones.
[0134] Such a relatively wide air ingress zone may be formed from a porous portion of the
wrapper having a relatively high porosity (as described above), a plurality of lines
of perforations or a line of relatively wide perforations.
[0135] By providing a wide air ingress zone, such as the first air ingress zone, there will
be more surface area of the first air ingress to overlap or to align with an outlet
of the air-flow channel of the aerosol-generating device. This would therefore reliably
ensure that a fluid communication between the exterior of the aerosol-generating device
and the interior of the aerosol-generating article received within the device is established
so that a consumer can suitably consume the article. Having a relatively wide air
ingress zone may account for any manufacturing imprecision of the air ingress zone
that may affect the alignment of an outlet of the air-flow channel of the device and
the air ingress zone.
[0136] An air ingress zone may fully or partially circumscribe the aerosol-generating article.
An air ingress zone may be located around the aerosol-generating article.
[0137] Each air ingress zone may provide or allow a certain level of air ingress into the
interior of the aerosol-generating article. A level of air ingress may refer to an
amount of fluid that is allowed to enter through an air ingress zone in order to enter
into the interior of the aerosol-generating article. The level of air ingress may
be expressed in terms of the volume of air, in cubic millimetres, that may enter via
an air ingress zone during a period of time, expressed in seconds. The level of air
ingress may be expressed as a mass flow rate, in grams or kilograms per second, or
a volume flow rate, millilitres or litres per second.
[0138] The level of air ingress into the interior of the aerosol-generating article through
the first air ingress zone may be configured to be greater than the level of air ingress
into the interior of aerosol-generating article through the second air ingress zone.
This is to ensure that a suitable amount of air flows through the first air ingress
zone during use, when the aerosol-generating article is received within an aerosol-generating
device, in order to serve as a primary air intake zone for the article, while the
second air ingress zone may provide ventilation to the article.
[0139] The level of air ingress through an air ingress zone may be defined as a volume flow
rate. The level of air ingress, that is, the volume flow rate, into the interior of
the aerosol-generating article through the first air ingress zone may be at least
about 10 percent greater than the level of air ingress (volume flow rate) into the
interior of the aerosol-generating article through the second air ingress zone. The
level of air ingress, that is, the volume flow rate, into the interior of the aerosol-generating
article through the first air ingress zone may be at least about 20 percent greater
than the level of air ingress (volume flow rate) into the interior of the aerosol-generating
article through the second air ingress zone. The level of air ingress, that is, the
volume flow rate, into the interior of the aerosol-generating article through the
first air ingress zone may be at least about 30 percent greater than the level of
air ingress (volume flow rate) into the interior of the aerosol-generating article
through the second air ingress zone.
[0140] The level of air ingress, that is, the volume flow rate, into the interior of the
aerosol-generating article through the first air ingress zone may be less than about
300 percent greater than the level of air ingress (volume flow rate) into the interior
of the aerosol-generating article through the second air ingress zone. The level of
air ingress, that is, the volume flow rate, into the interior of the aerosol-generating
article through the first air ingress zone may be less than about 200 percent greater
than the level of air ingress (volume flow rate) into the interior of the aerosol-generating
article through the second air ingress zone. The level of air ingress, that is, the
volume flow rate, into the interior of the aerosol-generating article through the
first air ingress zone may be less than about 100 percent greater than the level of
air ingress (volume flow rate) into the interior of the aerosol-generating article
through the second air ingress zone. The level of air ingress, that is, the volume
flow rate, into the interior of the aerosol-generating article through the first air
ingress zone may be less than about 90 percent greater than the level of air ingress
(volume flow rate) into the interior of the aerosol-generating article through the
second air ingress zone. The level of air ingress, that is, the volume flow rate,
into the interior of the aerosol-generating article through the first air ingress
zone may be less than about 75 percent greater than the level of air ingress (volume
flow rate) into the interior of the aerosol-generating article through the second
air ingress zone. The level of air ingress, that is, the volume flow rate, into the
interior of the aerosol-generating article through the first air ingress zone may
be less than about 60 percent greater than the level of air ingress (volume flow rate)
into the interior of the aerosol-generating article through the second air ingress
zone.
[0141] From a certain volume of air entering the aerosol-generating device through the air-flow
channel, or plurality of air-flow channels, during a period of time, a first proportion
of such a volume of air intake may enter into the interior of the aerosol-generating
article through the first air ingress zone and a second proportion of such a volume
of air intake may enter into the interior of the aerosol-generating article through
the second air ingress zone. For example, during a period of time T a volume V of
air may enter into the aerosol-generating device, then a first proportion of V, expressed
as a percentage of V, may enter into the interior of the aerosol-generating article
through the first air ingress zone and a second proportion of V may enter into the
interior of the aerosol-generating article through the second air ingress zone.
[0142] In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, at least about 50 percent of such total volume may enter
into the interior of the aerosol-generating article through the first air ingress
zone. In relation to a total volume of air intake entering the aerosol-generating
device during a period of time, at least about 55 percent of such total volume may
enter into the interior of the aerosol-generating article through the first air ingress
zone. In relation to a total volume of air intake entering the aerosol-generating
device during a period of time, at least about 60 percent of such total volume may
enter into the interior of the aerosol-generating article through the first air ingress
zone. In relation to a total volume of air intake entering the aerosol-generating
device during a period of time, at least about 70 percent of such total volume may
enter into the interior of the aerosol-generating article through the first air ingress
zone. In relation to a total volume of air intake entering the aerosol-generating
device during a period of time, at least about 75 percent of such total volume may
enter into the interior of the aerosol-generating article through the first air ingress
zone.
[0143] In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 50 percent or less of such total volume may enter into
the interior of the aerosol-generating article through the second air ingress zone.
In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 45 percent or less of such total volume may enter into
the interior of the aerosol-generating article through the second air ingress zone.
In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 40 percent or less of such total volume may enter into
the interior of the aerosol-generating article through the second air ingress zone.
In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 30 percent or less of such total volume may enter into
the interior of the aerosol-generating article through the second air ingress zone.
In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 25 percent or less of such total volume may enter into
the interior of the aerosol-generating article through the second air ingress zone.
[0144] In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 50 percent of such total volume may enter into the
interior of the aerosol-generating article through the first air ingress zone and
about 50 percent of such total volume may enter into the interior of the aerosol-generating
article through the second air ingress zone.
[0145] In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 55 percent of such total volume may enter into the
interior of the aerosol-generating article through the first air ingress zone and
45 percent of such total volume may enter into the interior of the aerosol-generating
article through the second air ingress zone.
[0146] In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 60 percent of such total volume may enter into the
interior of the aerosol-generating article through the first air ingress zone and
about 40 percent of such total volume may enter into the interior of the aerosol-generating
article through the second air ingress zone.
[0147] In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 70 percent of such total volume may enter into the
interior of the aerosol-generating article through the first air ingress zone and
about 30 percent of such total volume may enter into the interior of the aerosol-generating
article through the second air ingress zone.
[0148] In relation to a total volume of air intake entering the aerosol-generating device
during a period of time, about 75 percent of such total volume may enter into the
interior of the aerosol-generating article through the first air ingress zone and
about 25 percent of such total volume may enter into the interior of the aerosol-generating
article through the second air ingress zone.
[0149] Similarly, a certain volume flow rate may flow through the air-flow channel, or plurality
of air-flow channels, of the aerosol-generating device before the air exits the air-flow
channel towards the aerosol-generating article. From such an intake volume flow rate
(or air-flow channel volume flow rate existing in the air-flow channel prior to the
outlets), a first proportion of such intake volume flow rate may flow through the
first air ingress zone and a second proportion of such intake volume flow rate may
flow through the second air ingress zone. For example, a volume flow rate VF may flow
through the air-flow channel, then a first proportion of VF, expressed as a percentage
of VF, may flow through the first air ingress zone and a second proportion of VF may
flow through the second air ingress zone.
[0150] In relation to an intake volume flow rate flowing through the air-flow channel of
the aerosol-generating device, at least about 50 percent of such intake volume flow
rate may flow through the first air ingress zone. In relation to an intake volume
flow rate flowing through the air-flow channel of the aerosol-generating device, at
least about 55 percent of such intake volume flow rate may flow through the first
air ingress zone. In relation to an intake volume flow rate flowing through the air-flow
channel of the aerosol-generating device, at least about 60 percent of such intake
volume flow rate may flow through the first air ingress zone. In relation to an intake
volume flow rate flowing through the air-flow channel of the aerosol-generating device,
at least about 70 percent of such intake volume flow rate may flow through the first
air ingress zone. In relation to an intake volume flow rate flowing through the air-flow
channel of the aerosol-generating device, at least about 75 percent of such intake
volume flow rate may flow through the first air ingress zone.
[0151] In relation to an intake volume flow rate flowing through the air-flow channel of
the aerosol-generating device, about 50 percent or less of such intake volume flow
rate may flow through the second air ingress zone. In relation to an intake volume
flow rate flowing through the air-flow channel of the aerosol-generating device, about
45 percent or less of such intake volume flow rate may flow through the second air
ingress zone. In relation to an intake volume flow rate flowing through the air-flow
channel of the aerosol-generating device, about 40 percent or less of such intake
volume flow rate may flow through the second air ingress zone. In relation to an intake
volume flow rate flowing through the air-flow channel of the aerosol-generating device,
about 30 percent or less of such intake volume flow rate may flow through the second
air ingress zone. In relation to an intake volume flow rate flowing through the air-flow
channel of the aerosol-generating device, about 25 percent or less of such intake
volume flow rate may flow through the second air ingress zone.
[0152] In relation to an intake volume flow rate flowing through the air-flow channel of
the aerosol-generating device, about 50 percent of such intake volume flow rate may
flow through the first air ingress zone and about 50 percent of such intake volume
flow rate may flow through the second air ingress zone.
[0153] In relation to an intake volume flow rate flowing through the air-flow channel of
the aerosol-generating device, about 55 percent of such intake volume flow rate may
flow through the first air ingress zone and about 45 percent of such intake volume
flow rate may flow through the second air ingress zone.
[0154] In relation to an intake volume flow rate flowing through the air-flow channel of
the aerosol-generating device, about 60 percent of such intake volume flow rate may
flow through the first air ingress zone and about 40 percent of such intake volume
flow rate may flow through the second air ingress zone.
[0155] In relation to an intake volume flow rate flowing through the air-flow channel of
the aerosol-generating device, about 70 percent of such intake volume flow rate may
flow through the first air ingress zone and about 30 percent of such intake volume
flow rate may flow through the second air ingress zone.
[0156] In relation to an intake volume flow rate flowing through the air-flow channel of
the aerosol-generating device, about 75 percent of such intake volume flow rate may
flow through the first air ingress zone and about 25 percent of such intake volume
flow rate may flow through the second air ingress zone.
[0157] The term "ventilation level" may be used throughout the present specification to
denote a volume ratio between the airflow admitted into the aerosol-generating article
via an air ingress zone (air ingress airflow) and an airflow exiting the aerosol-generating
article via the mouth end, or downstream end. The greater the ventilation level, the
higher the dilution of the aerosol flow delivered to the consumer. The ventilation
level is measured on the aerosol-generating article on its own - that is, without
inserting the aerosol-generating article in a suitable aerosol-generating device adapted
to heat the aerosol-forming substrate.
[0158] The ventilation level provided by a first air ingress zone may be measured by occluding
all other air ingress zones, if present, and drawing air from the mouth end of the
aerosol-generating article so that air may flow through the front end or upstream
end of the aerosol-generating article and the first air ingress zone into the aerosol-generating
article. The ventilation level provided by the first air ingress zone may be defined
as the ratio between the flow rate of air (airflow) entering the aerosol-generating
article through the first air ingress zone and the flow rate of air exiting the aerosol-generating
article at the mouth end.
[0159] The ventilation level provided by a second air ingress zone may be measured by occluding
all other air ingress zones, if present, and drawing air from the mouth end of the
aerosol-generating article so that air may flow through the front end or upstream
end of the aerosol-generating article and the second air ingress zone into the aerosol-generating
article. The ventilation level provided by the second air ingress zone may be defined
as the ratio between the flow rate of air (airflow) entering the aerosol-generating
article through the second air ingress zone and the flow rate of air exiting the aerosol-generating
article at the mouth end.
[0160] The total ventilation level of the aerosol-generating article may be measured by
not occluding any of the air ingress zones present in the aerosol-generating article
and drawing air from the mouth end of the aerosol-generating article so that air may
flow through the front end or upstream end of the aerosol-generating article and the
air ingress zones into the aerosol-generating article. The total ventilation level
of the aerosol-generating article may be defined as the ratio between the sum of flow
rates of air entering the aerosol-generating article through each of the air ingress
zones and the flow rate of air exiting the aerosol-generating article at the mouth
end.
[0161] The ventilation level provided to the aerosol-generating article by a first air ingress
zone may be at least about 10 percent. The ventilation level provided by a first air
ingress zone may be at least about 20 percent. The ventilation level provided by a
first air ingress zone may be at least about 25 percent. The ventilation level provided
by a first air ingress zone may be at least about 50 percent. The ventilation level
provided by a first air ingress zone may be at least about 75 percent.
[0162] The ventilation level provided to the aerosol-generating article by a second air
ingress zone may be at least about 10 percent. The ventilation level provided by a
second air ingress zone may be at least about 20 percent. The ventilation level provided
by a second air ingress zone may be at least about 25 percent. The ventilation level
provided by a second air ingress zone may be at least about 50 percent. The ventilation
level provided by a second air ingress zone may be at least about 75 percent.
[0163] The ventilation level provided by the first air ingress zone or by the second air
ingress zone may be about 75 percent or less. The ventilation level provided by the
first air ingress zone or by the second air ingress zone may be about 60 percent or
less. The ventilation level provided by the first air ingress zone or by the second
air ingress zone may be about 50 percent or less.
[0164] The ventilation level provided by the first air ingress zone or by the second air
ingress zone may be between about 10 percent and about 75 percent. The ventilation
level provided by the first air ingress zone or by the second air ingress zone may
be between about 30 percent and about 60 percent.
[0165] The aerosol-generating article may typically have a total ventilation level of at
least about 10 percent, preferably at least about 20 percent.
[0166] The aerosol-generating article may have a total ventilation level of at least about
20 percent or about 25 percent or about 30 percent. The aerosol-generating article
may have a total ventilation level of at least about 35 percent. The aerosol-generating
article may have a total ventilation level of less than about 60 percent. The aerosol-generating
article may have a total ventilation level of less than about 50 percent or less than
about 40 percent. The aerosol-generating article may have a total ventilation level
between about 25 percent and about 60 percent.
[0167] The aerosol-generating article may have a total ventilation level from about 10 percent
to about 90 percent. The aerosol-generating article may have a total ventilation level
from about 20 percent to about 80 percent. The aerosol-generating article may have
a total ventilation level from about 25 percent to about 60 percent. The aerosol-generating
article may have a total ventilation level from about 30 percent to about 50 percent.
The aerosol-generating article may have a total ventilation level from about 30 percent
to about 40 percent.
[0168] The aerosol-generating article may have a total ventilation level from about 28 percent
to about 42 percent. The aerosol-generating article may have a ventilation level of
about 35 percent. The inventors have surprisingly found that the diluting effect on
the aerosol - which can be assessed by measuring, in particular, the effect on the
delivery of glycerin included in the aerosol-forming substrate as the aerosol former
- is advantageously minimised when the ventilation level is between about 30 percent
and about 50 percent. In particular, ventilation levels between about 35 percent and
about 42 percent have been found to lead to particularly satisfactory values of glycerin
delivery. At the same time, the extent of nucleation and, as a consequence, the delivery
of nicotine and aerosol-former (for example, glycerol) are enhanced.
[0169] The first air ingress zone may serve as a first, or primary, air intake zone and
the second air ingress zone may serve as a ventilation zone of the aerosol-generating
article. This is because the first ingress zone will be configured to be the first
point of intake of air when the aerosol-generating article is located within the device
cavity and may be configured to admit the highest level of air compared to any other
of the air ingress zone provided on the wrapper of the article.
[0170] The first air ingress zone will ensure compatibility between aerosol-generating article
and aerosol-generating device, as described above, by defining the primary air intake
zone of the article, while the second air ingress zone will provide ventilation to
the aerosol-generating article during normal use, when the aerosol-generating article
is received within the device. All air ingress zones may be located within the device
cavity, or heating chamber, of the aerosol-generating device during normal use. This
will prevent a user from inadvertently obscuring any of the air ingress zone during
normal use with a hand or lips, which could negatively affect a user's experience
as the article may not be as well ventilated.
[0171] There are benefits to providing ventilation to an aerosol-generating article during
normal use. Without wishing to be bound by theory, it has been found that the temperature
drop caused by the admission of cooler, external air into the hollow tubular segment
via the ventilation zone may have an advantageous effect on the nucleation and growth
of aerosol particles.
[0172] In this scenario, which may be further complicated by coalescence phenomena, the
temperature and rate of cooling can play a critical role in determining how the system
responds. In general, different cooling rates may lead to significantly different
temporal behaviours as concerns the formation of the liquid phase (droplets), because
the nucleation process is typically nonlinear. Without wishing to be bound by theory,
it is hypothesised that cooling can cause a rapid increase in the number concentration
of droplets, which is followed by a strong, short-lived increase in this growth (nucleation
burst). This nucleation burst would appear to be more significant at lower temperatures.
Further, it would appear that higher cooling rates may favour an earlier onset of
nucleation. By contrast, a reduction of the cooling rate would appear to have a favourable
effect on the final size that the aerosol droplets ultimately reach.
[0173] Therefore, the rapid cooling induced by the admission of external air into the hollow
tubular segment via the ventilation zone can be favourably used to favour nucleation
and growth of aerosol droplets. However, at the same time, the admission of external
air into the hollow tubular segment has the immediate drawback of diluting the aerosol
stream delivered to the consumer.
[0174] In addition, it has been found that in aerosol-generating articles in accordance
with the invention the cooling and diluting effect caused by the admission of ventilation
air at the location along the conduit defined by the hollow tubular segment described
above has a surprising reducing effect on the generation and delivery of phenol-containing
species.
[0175] This is understood to be advantageous in that, by concentrating the cooling effect
brought about by ventilation over a short portion of the cavity defined by the hollow
tubular segment, it may be possible to further enhance aerosol nucleation. This is
because a faster and more drastic cooling of the stream of volatilised species from
the aerosol-forming substrate is expected to particularly favour the formation of
new nuclei of aerosol particles
[0176] The rod of aerosol-forming substrate preferably has an external diameter that is
approximately equal to the external diameter of the aerosol-generating article.
[0177] Preferably, the rod of aerosol-forming substrate has an external diameter of at least
about 4 millimetres (mm). The rod of aerosol-forming substrate may have an external
diameter of at least about 5 millimetres. The rod of aerosol-forming substrate may
have an external diameter of between about 5 millimetres and about 12 millimetres,
for example of between about 5 millimetres and about 10 millimetres or of between
about 6 millimetres and about 8 millimetres. In a preferred embodiment, the rod of
aerosol-forming substrate has an external diameter of 7.2 millimetres, to within 10
percent.
[0178] The rod of aerosol-forming substrate may have a length of between about 5 millimetres
and about 100 mm. Preferably, the rod of aerosol-forming substrate has a length of
at least about 5 millimetres, more preferably at least about 7 millimetres. In addition,
or as an alternative, the rod of aerosol-forming substrate preferably has a length
of less than about 80 millimetres, more preferably less than about 65 millimetres,
even more preferably less than about 50 millimetres. In particularly preferred embodiments,
the rod of aerosol-forming substrate has a length of less than about 35 millimetres,
more preferably less than 25 millimetres, even more preferably less than about 20
millimetres. In one embodiment, the rod of aerosol-forming substrate may have a length
of about 10 millimetres. In a preferred embodiment, the rod of aerosol-forming substrate
has a length of about 12 millimetres.
[0179] Preferably, the rod of aerosol-forming substrate has a substantially uniform cross-section
along the length of the rod. Particularly preferably, the rod of aerosol-forming substrate
has a substantially circular cross-section.
[0180] In preferred embodiments, the aerosol-forming substrate comprises one or more gathered
sheets of homogenised tobacco material. The one or more sheets of homogenised tobacco
material may be textured. As used herein, the term 'textured sheet' denotes a sheet
that has been crimped, embossed, debossed, perforated or otherwise deformed. Textured
sheets of homogenised tobacco material for use in the invention may comprise a plurality
of spaced-apart indentations, protrusions, perforations or a combination thereof.
The rod of aerosol-forming substrate may comprise a gathered crimped sheet of homogenised
tobacco material circumscribed by a wrapper.
[0181] In certain preferred embodiments, the aerosol-forming substrate comprises homogenised
plant material, preferably a homogenised tobacco material.
[0182] As used herein, the term "homogenised plant material" encompasses any plant material
formed by the agglomeration of particles of plant. For example, sheets or webs of
homogenised tobacco material for the aerosol-forming substrates of the present invention
may be formed by agglomerating particles of tobacco material obtained by pulverising,
grinding or comminuting plant material and optionally one or more of tobacco leaf
lamina and tobacco leaf stems. The homogenised plant material may be produced by casting,
extrusion, paper making processes or other any other suitable processes known in the
art.
[0183] The homogenised plant material can be provided in any suitable form. For example,
the homogenised plant material may be in the form of one or more sheets. As used herein
with reference to the invention, the term "sheet" describes a laminar element having
a width and length substantially greater than the thickness thereof.
[0184] Alternatively or in addition, the homogenised plant material may be in the form of
a plurality of pellets or granules.
[0185] Alternatively or in addition, the homogenised plant material may be in the form of
a plurality of strands, strips or shreds. As used herein, the term "strand" describes
an elongate element of material having a length that is substantially greater than
the width and thickness thereof. The term "strand" should be considered to encompass
strips, shreds and any other homogenised plant material having a similar form. The
strands of homogenised plant material may be formed from a sheet of homogenised plant
material, for example by cutting or shredding, or by other methods, for example, by
an extrusion method.
[0186] 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, the crimped sheet of homogenised tobacco material has
a plurality of ridges or corrugations substantially parallel to the cylindrical axis
of the rod according to the invention. This advantageously facilitates gathering of
the crimped sheet of homogenised tobacco material to form the rod. However, it will
be appreciated that crimped sheets of homogenised tobacco material for use in the
invention 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. In certain embodiments, sheets of homogenised tobacco material for use
in the rod of the article of the invention may be substantially evenly textured over
substantially their entire surface. For example, crimped sheets of homogenised tobacco
material for use in the manufacture of a rod for use in an aerosol-generating article
in accordance with the invention may comprise a plurality of substantially parallel
ridges or corrugations that are substantially evenly spaced-apart across the width
of the sheet.
[0187] Sheets or webs of homogenised tobacco material for use in the invention may have
a tobacco content of at least about 40 percent by weight on a dry weight basis, more
preferably of at least about 60 percent by weight on a dry weight basis, more preferably
or at least about 70 percent by weight on a dry basis and most preferably at least
about 90 percent by weight on a dry weight basis.
[0188] Sheets or webs of homogenised tobacco material for use in the aerosol-forming substrate
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 for use in the aerosol-forming substrate 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.
[0189] The homogenised plant, or tobacco, material comprises tobacco particles, or material,
in combination with non-tobacco plant flavour particles. The non-tobacco plant flavour
particles may be selected from one or more of: ginger particles, rosemary particles,
eucalyptus particles, clove particles and star anise particles.
[0190] Suitable extrinsic binders for inclusion in sheets or webs of homogenised tobacco
material for use in the aerosol-forming substrate 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.
[0191] Suitable non-tobacco fibres for inclusion in sheets or webs of homogenised tobacco
material for use in the aerosol-forming substrate are known in the art and include,
but are not limited to: cellulose fibres; soft-wood fibres; hard-wood fibres; jute
fibres and combinations thereof. Prior to inclusion in sheets of homogenised tobacco
material for use in the aerosol-forming substrate, non-tobacco fibres may be treated
by suitable processes known in the art including, but not limited to: mechanical pulping;
refining; chemical pulping; bleaching; sulphate pulping; and combinations thereof.
[0192] In other embodiments of the present invention, the aerosol-forming substrate may
comprise a gel composition that includes an alkaloid compound, or a cannabinoid compound,
or both an alkaloid compound and a cannabinoid compound. The aerosol-forming substrate
may comprise a gel composition that includes nicotine. The aerosol-forming substrate
may comprise a gel composition that does not include nicotine.
[0193] Preferably, the gel composition comprises an alkaloid compound, or a cannabinoid
compound, or both an alkaloid compound and a cannabinoid compound; an aerosol former;
and at least one gelling agent. Preferably, the at least one gelling agent forms a
solid medium and the glycerol is dispersed in the solid medium, with the alkaloid
or cannabinoid dispersed in the glycerol. Preferably, the gel composition is a stable
gel phase.
[0194] Advantageously, a stable gel composition comprising nicotine provides predictable
composition form upon storage or transit from manufacture to the consumer. The stable
gel composition comprising nicotine substantially maintains its shape. The stable
gel composition comprising nicotine substantially does not release a liquid phase
upon storage or transit from manufacture to the consumer. The stable gel composition
comprising nicotine may provide for a simple consumable design. This consumable may
not have to be designed to contain a liquid, thus a wider range of materials and container
constructions may be contemplated.
[0195] The gel composition described herein may be combined with an aerosol-generating device
to provide a nicotine aerosol to the lungs at inhalation or air flow rates that are
within conventional smoking regime inhalation or air flow rates. The aerosol-generating
device may continuously heat the gel composition. A consumer may take a plurality
of inhalations or "puffs" where each "puff" delivers an amount of nicotine aerosol.
The gel composition may be capable of delivering a high nicotine/low total particulate
matter (TPM) aerosol to a consumer when heated, preferably in a continuous manner.
[0196] The phrase "stable gel phase" or "stable gel" refers to gel that substantially maintains
its shape and mass when exposed to a variety of environmental conditions. The stable
gel may not substantially release (sweat) or absorb water when exposed to a standard
temperature and pressure while varying relative humidity from about 10 percent to
about 60 percent. For example, the stable gel may substantially maintain its shape
and mass when exposed to a standard temperature and pressure while varying relative
humidity from about 10 percent to about 60 percent.
[0197] The gel composition includes an alkaloid compound, or a cannabinoid compound, or
both an alkaloid compound and a cannabinoid compound. The gel composition may include
one or more alkaloids. The gel composition may include one or more cannabinoids. The
gel composition may include a combination of one or more alkaloids and one or more
cannabinoids.
[0198] The term "alkaloid compound" refers to any one of a class of naturally occurring
organic compounds that contain one or more basic nitrogen atoms. Generally, an alkaloid
contains at least one nitrogen atom in an amine-type structure. This or another nitrogen
atom in the molecule of the alkaloid compound can be active as a base in acid-base
reactions. Most alkaloid compounds have one or more of their nitrogen atoms as part
of a cyclic system, such as for example a heterocylic ring. In nature, alkaloid compounds
are found primarily in plants, and are especially common in certain families of flowering
plants. However, some alkaloid compounds are found in animal species and fungi. In
this disclosure, the term "alkaloid compound" refers to both naturally derived alkaloid
compounds and synthetically manufactured alkaloid compounds.
[0199] The gel composition may preferably include an alkaloid compound selected from the
group consisting of nicotine, anatabine, and combinations thereof.
[0200] Preferably the gel composition includes nicotine.
[0201] The term "nicotine" refers to nicotine and nicotine derivatives such as free-base
nicotine, nicotine salts and the like.
[0202] The term "cannabinoid compound" refers to any one of a class of naturally occurring
compounds that are found in parts of the cannabis plant - namely the species Cannabis
sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are especially
concentrated in the female flower heads. Cannabinoid compounds naturally occurring
in the cannabis plant include cannabidiol (CBD) and tetrahydrocannabinol (THC). In
this disclosure, the term "cannabinoid compounds" is used to describe both naturally
derived cannabinoid compounds and synthetically manufactured cannabinoid compounds.
[0203] The gel may include a cannabinoid compound selected from the group consisting of
cannabidiol (CBD), tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA),
cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC),
cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin
(CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethyl
ether (CBGM), cannabielsoin (CBE),cannabicitran (CBT), and combinations thereof.
[0204] The gel composition may preferably include a cannabinoid compound selected from the
group consisting of cannabidiol (CBD), THC (tetrahydrocannabinol) and combinations
thereof.
[0205] The gel may preferably include cannabidiol (CBD).
[0206] The gel composition may include nicotine and cannabidiol (CBD).
[0207] The gel composition may include nicotine, cannabidiol (CBD), and THC (tetrahydrocannabinol).
[0208] The gel composition preferably includes an aerosol-former. Ideally the aerosol-former
is substantially resistant to thermal degradation at the operating temperature of
the associated aerosol-generating device. Suitable aerosol-formers 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. Polyhydric alcohols or mixtures thereof, may be one
or more of triethylene glycol, 1, 3-butanediol and, glycerine (glycerol or propane-1,2,3-triol)
or polyethylene glycol. The aerosol-former is preferably glycerol.
[0209] Preferably, in embodiments in which the rod of aerosol-forming substrate comprises
a gel composition, as described above, the downstream section of the aerosol-generating
article comprises an aerosol-cooling element having a length of less than about 10
millimetres. The use of a relatively short aerosol-cooling element in combination
with a gel composition has found to optimise the delivery of aerosol to the consumer.
[0210] Embodiments of the invention in which the rod of aerosol-forming substrate comprises
a gel composition, as described above, preferably comprise an upstream element (or
upstream section) upstream of the rod of aerosol-forming substrate. In this case,
the upstream element or section advantageously prevents physical contact with the
gel composition. The upstream element or section can also advantageously compensate
for any potential reduction in RTD, for example, due to evaporation of the gel composition
upon heating of the rod of aerosol-forming substrate during use.
[0211] The sheets or webs of homogenised tobacco material may comprise an aerosol former.
As used herein, the term "aerosol former" describes any suitable known compound or
mixture of compounds that, in use, facilitates formation of an aerosol and that is
substantially resistant to thermal degradation at the operating temperature of the
aerosol-generating article.
[0212] Suitable aerosol-formers are known in the art and include, but are not limited to:
polyhydric alcohols, such as propylene glycol, 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.
[0213] Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as propylene
glycol, triethylene glycol, 1,3-butanediol and, most preferred, glycerine.
[0214] The sheets or webs of homogenised tobacco material may comprise a single aerosol
former. Alternatively, the sheets or webs of homogenised tobacco material may comprise
a combination of two or more aerosol formers.
[0215] The sheets or webs of homogenised tobacco material have an aerosol former content
of greater than 10 percent on a dry weight basis. Preferably, the sheets or webs of
homogenised tobacco material have an aerosol former content of greater than 12 percent
on a dry weight basis. More preferably, the sheets or webs of homogenised tobacco
material have an aerosol former content of greater than 14 percent on a dry weight
basis. Even more preferably the sheets or webs of homogenised tobacco material have
an aerosol former content of greater than 16 percent on a dry weight basis.
[0216] The sheets of homogenised tobacco material may have an aerosol former content of
between approximately 10 percent and approximately 30 percent on a dry weight basis.
Preferably, the sheets or webs of homogenised tobacco material have an aerosol former
content of less than 25 percent on a dry weight basis.
[0217] In a preferred embodiment, the sheets of homogenised tobacco material have an aerosol
former content of approximately 20 percent on a dry weight basis.
[0218] Sheets or webs of homogenised tobacco for use in the aerosol-generating article of
the present invention may be made by methods known in the art, for example the methods
disclosed in International patent application
WO-A-2012/164009 A2. In a preferred embodiment, sheets of homogenised tobacco material for use in the
aerosol-generating article are formed from a slurry comprising particulate tobacco,
guar gum, cellulose fibres and glycerine by a casting process.
[0219] Alternative arrangements of homogenised tobacco material in a rod for use in an aerosol-generating
article will be known to the skilled person and may include a plurality of stacked
sheets of homogenised tobacco material, a plurality of elongate tubular elements formed
by winding strips of homogenised tobacco material about their longitudinal axes, etc.
[0220] As a further alternative, the rod of aerosol-forming substrate may comprise a non-tobacco-based,
nicotine-bearing material, such as a sheet of sorbent non-tobacco material loaded
with nicotine (for example, in the form of a nicotine salt) and an aerosol-former.
Examples of such rods are described in the international application
WO-A-2015/052652. In addition, or as an alternative, the rod of aerosol-forming substrate may comprise
a non-tobacco plant material, such as an aromatic non-tobacco plant material.
[0221] The aerosol-forming substrate is circumscribed by a wrapper. The wrapper may be formed
of a porous or non-porous sheet material. The wrapper may be formed of any suitable
material or combination of materials. Preferably, the wrapper is a paper wrapper.
[0222] The mouthpiece segment comprises a plug of filtration material capable of removing
particulate components, gaseous components or a combination. 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, viscose fibres, polyhydroxyalkanoates
(PHA) fibres, polylactic acid (PLA) fibres and paper; adsorbents such as, for example,
activated alumina, zeolites, molecular sieves and silica gel; and combinations thereof.
In addition, the plug of filtration material may further comprise one or more aerosol-modifying
agent. Suitable aerosol-modifying agents are known in the art and include, but are
not limited to, flavourants such as, for example, menthol. In some embodiments, the
mouthpiece segment may further comprise a mouth end recess downstream of the plug
of filtration material. By way of example, the mouthpiece segment may comprise a hollow
tube arranged in longitudinal alignment with, and immediately downstream of the plug
of filtration material, the hollow tube forming a cavity at the mouth end that is
open to the outer environment at the downstream end of the mouthpiece segment and
of the aerosol-generating article.
[0223] A length of the mouthpiece segment is preferably at least about 4 millimetres, more
preferably at least about 6 millimetres, even more preferably at least about 8 millimetres.
In addition, or as an alternative, a length of the mouthpiece segment is preferably
less than 25 millimetres, more preferably less than 20 millimetres, even more preferably
less than 15 millimetres. In some preferred embodiments, a length of the mouthpiece
segment is from about 4 millimetres to about 25 millimetres, more preferably from
about 6 millimetres to about 20 millimetres. The length of the mouthpiece segment
may be about 7 millimetres. The length of the mouthpiece segment may be about 12 millimetres.
[0224] A length of the hollow tubular segment is preferably at least about 10 millimetres.
More preferably, a length of the hollow tubular segment is at least about 15 millimetres.
In addition, or as an alternative, a length of the hollow tubular segment is preferably
less than about 30 millimetres. More preferably, a length of the hollow tubular segment
is less than about 25 millimetres. Even more preferably, a length of the hollow tubular
segment is less than about 20 millimetres. In some preferred embodiments, a length
of the hollow tubular segment is from about 10 millimetres to about 30 millimetres,
more preferably from about 12 millimetres to about 25 millimetres, even more preferably
from about 15 millimetres to about 20 millimetres. By way of example, in a particularly
preferred embodiment the length of the hollow tubular segment is about 18 millimetres.
In another particularly preferred embodiment the length of the hollow tubular segment
is about 13 millimetres.
[0225] A length of the aerosol-cooling element is preferably at least about 10 millimetres.
More preferably, a length of the aerosol-cooling element is at least about 15 millimetres.
In addition, or as an alternative, a length of the aerosol-cooling element is preferably
less than about 30 millimetres. More preferably, a length of the aerosol-cooling element
is less than about 25 millimetres. Even more preferably, a length of the aerosol-cooling
element is less than about 20 millimetres. In some preferred embodiments, a length
of the aerosol-cooling element is from about 10 millimetres to about 30 millimetres,
more preferably from about 12 millimetres to about 25 millimetres, even more preferably
from about 15 millimetres to about 20 millimetres. By way of example, in a particularly
preferred embodiment the length of the aerosol-cooling element is about 18 millimetres.
In another particularly preferred embodiment the length of the aerosol-cooling element
is about 13 millimetres.
[0226] An overall length of an aerosol-generating article in accordance with the invention
is preferably at least about 40 millimetres. In addition, or as an alternative, an
overall length of the aerosol-generating article in accordance with the invention
is preferably less than about 70 millimetres, more preferably less than 60 millimetres,
even more preferably less than 50 millimetres. In preferred embodiments, an overall
length of the aerosol-generating article is from about 40 millimetres to about 70
millimetres. In an exemplary embodiment, an overall length of the aerosol-generating
article is about 45 millimetres.
[0227] The support element (or support segment) may have a length of between about 5 millimetres
and about 15 millimetres. In a preferred embodiment, the support element has a length
of about 8 millimetres.
[0228] The aerosol-generating article preferably has an overall RTD of less than about 90
millimetres H2O (about 900 Pa). More preferably, the aerosol-generating article has
an overall RTD of less than about 80 millimetres H2O (about 800 Pa). Even more preferably,
the aerosol-generating article has an overall RTD of less than about 70 millimetres
H2O (about 700 Pa).
[0229] In addition, or as an alternative, the aerosol-generating article preferably has
an overall RTD of at least about 30 millimetres H2O (about 300 Pa). More preferably
the aerosol-generating article has an overall RTD of at least about 40 millimetres
H2O (about 400 Pa). Even more preferably, the aerosol-generating article has an overall
RTD of at least about 50 millimetres H2O (about 500 Pa).
[0230] The RTD of the aerosol-generating article may be assessed as the negative pressure
that has to be applied, under test conditions as defined in ISO 3402, to downstream
end of the mouthpiece in order to sustain a steady volumetric flow of air of 17.5
ml/s through the mouthpiece. The values of RTD listed above are intended to be measured
on the aerosol-generating article on its own (that is, prior to inserting the article
into an aerosol-generating device) without blocking the perforations of the ventilation
zone.
[0231] As used in the present specification, the term "homogenised tobacco material" encompasses
any tobacco material formed by the agglomeration of particles of tobacco material.
Sheets or webs of homogenised tobacco material are formed by agglomerating particulate
tobacco obtained by grinding or otherwise powdering of one or both of tobacco leaf
lamina and tobacco leaf stems. In addition, homogenised tobacco material may comprise
a minor quantity of one or more of tobacco dust, tobacco fines, and other particulate
tobacco by-products formed during the treating, handling and shipping of tobacco.
The sheets of homogenised tobacco material may be produced by casting, extrusion,
paper making processes or other any other suitable processes known in the art.
[0232] The support element may be formed from any suitable material or combination of materials.
For example, the support element may be formed from one or more materials selected
from the group consisting of: cellulose acetate; cardboard; crimped paper, such as
crimped heat resistant paper or crimped parchment paper; and polymeric materials,
such as low density polyethylene (LDPE). In a preferred embodiment, the support element
is formed from cellulose acetate.
[0233] The aerosol-generating device may comprise an extractor for extracting the aerosol-generating
article received in the aerosol-generating device, the extractor being configured
to be moveable within the device cavity.
[0234] The extractor may be configured to expose the air-flow channel when the extractor
is in an operating position, the operating position being defined by the heater being
in contact with the aerosol-forming substrate of the aerosol-generating article.
[0235] The extractor comprises a receptacle body configured to receive an aerosol-generating
article. The receptacle body of the extractor (the extractor body) may comprise an
end-wall and a peripheral wall. The receptacle body of the extractor comprises an
open end, opposite the end-wall, through which an aerosol-generating article can be
received. The aerosol-generating article is configured to abut the end-wall once received
within the extractor body. The peripheral wall of the receptacle body may circumscribe
the aerosol-generating article when received within the extractor. In such embodiments
where an extractor is present, the peripheral wall of the extractor body may define
the air-flow channel. Alternatively, the peripheral wall of the device housing may
define the air-flow channel.
[0236] The extractor may be sized such that, in the operating position, the receptacle body
extends between a first end of the air-flow channel and the distal end of the device
cavity. This enables the aerosol-generating article to be directly exposed to the
air-flow channel without having the extractor body obscuring fluid communication between
the air-flow channel and the aerosol-generating article.
[0237] The extractor may be sized such that, in the operating position, the receptacle body
extends between the mouth end of the device cavity and the distal end of the device
cavity. In such embodiments, the extractor body may have a cut-out, or a plurality
of cut-outs, to allow exposure of the air-flow channel to the aerosol-generating article
when inserted. The extractor body and the device cavity together may be configured
to ensure alignment during use of said cut-out, or plurality of cut-outs, with the
air-flow channel, or the plurality of air-flow channel. For example, the extractor
body may comprise a projection arranged to cooperate with a slot or groove located
in the housing of the aerosol-generating device.
[0238] The aerosol-generating device may comprise an elongate heater arranged for insertion
into an aerosol-generating article when an aerosol-generating article is received
within the device cavity. The elongate heater may be arranged with the device cavity.
The elongate heater may extend into the device cavity. Alternative heating arrangements
are discussed further below. However, in such embodiments where the heater extends
into the device cavity, the extractor body comprises an aperture at an end-wall for
allowing the heater to extend into the aerosol-generating article. Such an aperture
may allow air to enter the interior of the extractor cavity, so that air may flow
through the rod of aerosol-forming substrate of the aerosol-generating article during
use. Alternatively, further apertures may be provided in order to allow air to enter
the interior of the extractor cavity.
[0239] In some embodiments, the length of the extractor body may be less than the length
of the device cavity. In such embodiments, when the extractor is in the operating
position (when the extractor is in abutment with the distal end of the device cavity),
the air-flow channel may be defined by the portion of the peripheral wall of the device
housing not circumscribing the extractor. Such a portion of the peripheral wall may
define the air-flow channel when the extractor is in the operating position. Effectively,
said portion of the peripheral wall of the device housing may extend longitudinally
past the extractor to define an air-flow channel. The spacing or gap between the aerosol-generating
article and the peripheral wall of the device housing defines the air-flow channel.
[0240] In embodiments where there is an extractor provided, an air-flow channel may be defined
between the peripheral wall of the aerosol-generating device housing and an external
surface of the extractor. Alternatively, an air-flow channel may be defined within
the extractor body. The air-flow channel may be defined in the peripheral wall of
the extractor body. The air-flow channel may be defined within the thickness of the
peripheral wall of the extractor body. The air-flow channel may extend along the length
of the extractor body. The air-flow channel may extend from a longitudinal position
away from the end-wall of the extractor body to a longitudinal position near, or at,
the open end of the extractor body.
[0241] In embodiments where there is no extractor provided, an air-flow channel may be defined
within the thickness of the peripheral wall of the aerosol-generating device housing.
[0242] The heater may comprise an elongate heating element configured to penetrate the rod
of aerosol-forming substrate when the aerosol-generating article is received within
the aerosol-generating device.
[0243] The heater may be any suitable type of heater. The heater may internally heat the
aerosol-generating article. Alternatively, the heater may externally heat the aerosol-generating
article. Such an external heater may circumscribe the aerosol-generating article when
inserted in or received within the aerosol-generating device.
[0244] In some embodiments, the heater is arranged to heat the outer surface of the aerosol-forming
substrate. In some embodiments, the heater is arranged for insertion into an aerosol-forming
substrate when the aerosol-forming substrate is received within the cavity. The heater
may be positioned within the cavity. The heater may extend into the cavity. The heater
may be an elongate heater. The elongate heater may be blade-shaped. The elongate heater
may be pin-shaped. The elongate heater may be cone-shaped. In some embodiments, the
aerosol-generating device comprises an elongate heater arranged for insertion into
an aerosol-generating article when an aerosol-generating article is received within
the cavity.
[0245] The heater may comprise at least one heating element. The at least one heating element
may be any suitable type of heating element. In some embodiments, the device comprises
only one heating element. In some embodiments, the device comprises a plurality of
heating elements. The heater may comprise at least one resistive heating element.
Preferably, the heater comprises a plurality of resistive heating elements. Preferably,
the resistive heating elements are electrically connected in a parallel arrangement.
Advantageously, providing a plurality of resistive heating elements electrically connected
in a parallel arrangement may facilitate the delivery of a desired electrical power
to the heater while reducing or minimising the voltage required to provide the desired
electrical power. Advantageously, reducing or minimising the voltage required to operate
the heater may facilitate reducing or minimising the physical size of the power supply.
[0246] Suitable materials for forming the at least one resistive heating element include
but are not limited to: semiconductors such as doped ceramics, electrically 'conductive'
ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals,
metal alloys and composite materials made of a ceramic material and a metallic material.
Such composite materials may comprise doped or undoped ceramics. Examples of suitable
doped ceramics include doped silicon carbides. Examples of suitable metals include
titanium, zirconium, tantalum and metals from the platinum group. Examples of suitable
metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminium- titanium-
zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-,
manganese- and iron-containing alloys, and super-alloys based on nickel, iron, cobalt,
stainless steel, Timetal
® and iron-manganese-aluminium based alloys.
[0247] In some embodiments, the at least one resistive heating element comprises one or
more stamped portions of electrically resistive material, such as stainless steel.
Alternatively, the at least one resistive heating element may comprise a heating wire
or filament, for example a Ni-Cr (Nickel-Chromium), platinum, tungsten or alloy wire.
[0248] In some embodiments, the at least one heating element comprises an electrically insulating
substrate, wherein the at least one resistive heating element is provided on the electrically
insulating substrate.
[0249] The electrically insulating substrate may comprise any suitable material. For example,
the electrically insulating substrate may comprise one or more of: paper, glass, ceramic,
anodized metal, coated metal, and Polyimide. The ceramic may comprise mica, Alumina
(AI2O3) or Zirconia (ZrO2). Preferably, the electrically insulating substrate has
a thermal conductivity of less than or equal to about 40 Watts per metre Kelvin, preferably
less than or equal to about 20 Watts per metre Kelvin and ideally less than or equal
to about 2 Watts per metre Kelvin.
The heater may comprise a heating element comprising a rigid electrically insulating
substrate with one or more electrically conductive tracks or wire disposed on its
surface. The size and shape of the electrically insulating substrate may allow it
to be inserted directly into an aerosol-forming substrate. If the electrically insulating
substrate is not sufficiently rigid, the heating element may comprise a further reinforcement
means. A current may be passed through the one or more electrically conductive tracks
to heat the heating element and the aerosol-forming substrate.
[0250] In some embodiments, the heater comprises an inductive heating arrangement. The inductive
heating arrangement may comprise an inductor coil and a power supply configured to
provide high frequency oscillating current to the inductor coil. As used herein, a
high frequency oscillating current means an oscillating current having a frequency
of between 500 kHz and 30 MHz. The heater may advantageously comprise a DC/AC inverter
for converting a DC current supplied by a DC power supply to the alternating current.
The inductor coil may be arranged to generate a high frequency oscillating electromagnetic
field on receiving a high frequency oscillating current from the power supply. The
inductor coil may be arranged to generate a high frequency oscillating electromagnetic
field in the device cavity. In some embodiments, the inductor coil may substantially
circumscribe the device cavity. The inductor coil may extend at least partially along
the length of the device cavity.
[0251] The heater may comprise an inductive heating element. The inductive heating element
may be a susceptor element. As used herein, the term 'susceptor element' refers to
an element comprising a material that is capable of converting electromagnetic energy
into heat. When a susceptor element is located in an alternating electromagnetic field,
the susceptor is heated. Heating of the susceptor element may be the result of at
least one of hysteresis losses and eddy currents induced in the susceptor, depending
on the electrical and magnetic properties of the susceptor material.
[0252] A susceptor element may be arranged such that, when the aerosol-generating article
is received in the cavity of the aerosol-generating device, the oscillating electromagnetic
field generated by the inductor coil induces a current in the susceptor element, causing
the susceptor element to heat up. In these embodiments, the aerosol-generating device
is preferably capable of generating a fluctuating electromagnetic field having a magnetic
field strength (H-field strength) of between 1 and 5 kilo amperes per metre (kA m),
preferably between 2 and 3 kA/m, for example about 2.5 kA/m. The electrically-operated
aerosol-generating device is preferably capable of generating a fluctuating electromagnetic
field having a frequency of between 1 and 30 MHz, for example between 1 and 10 MHz,
for example between 5 and 7 MHz.
[0253] In some embodiments, a susceptor element is located in the aerosol-generating article.
In these embodiments, the susceptor element is preferably located in contact with
the aerosol-forming substrate. The susceptor element may be located in the aerosol-forming
substrate.
[0254] In some embodiments, a susceptor element is located in the aerosol-generating device.
In these embodiments, the susceptor element may be located in the cavity. The aerosol-generating
device may comprise only one susceptor element. The aerosol-generating device may
comprise a plurality of susceptor elements.
[0255] In some embodiments, the susceptor element is arranged to heat the outer surface
of the aerosol-forming substrate. In some embodiments, the susceptor element is arranged
for insertion into an aerosol-forming substrate when the aerosol-forming substrate
is received within the cavity.
[0256] The susceptor element may comprise any suitable material. The susceptor element may
be formed from any material that can be inductively heated to a temperature sufficient
to release volatile compounds from the aerosol-forming substrate. Suitable materials
for the elongate susceptor element include graphite, molybdenum, silicon carbide,
stainless steels, niobium, aluminium, nickel, nickel containing compounds, titanium,
and composites of metallic materials. Some susceptor elements comprise a metal or
carbon. Advantageously the susceptor element may comprise or consist of a ferromagnetic
material, for example, ferritic iron, a ferromagnetic alloy, such as ferromagnetic
steel or stainless steel, ferromagnetic particles, and ferrite. A suitable susceptor
element may be, or comprise, aluminium. The susceptor element preferably comprises
more than about 5 percent, preferably more than about 20 percent, more preferably
more than about 50 percent or more than about 90 percent of ferromagnetic or paramagnetic
materials. Some elongate susceptor elements may be heated to a temperature in excess
of about 250 degrees Celsius.
[0257] The susceptor element may comprise a non-metallic core with a metal layer disposed
on the non-metallic core. For example, the susceptor element may comprise metallic
tracks formed on an outer surface of a ceramic core or substrate.
[0258] In some embodiments the aerosol-generating device may comprise at least one resistive
heating element and at least one inductive heating element. In some embodiments the
aerosol-generating device may comprise a combination of resistive heating elements
and inductive heating elements.
[0259] The aerosol-generating device may comprise a power supply. The power supply may be
a DC power supply. In some embodiments, the power supply is a battery. The power supply
may be a nickel-metal hydride battery, a nickel cadmium battery, or a lithium based
battery, for example a lithium-cobalt, a lithium-iron-phosphate or a lithium-polymer
battery. However, in some embodiments the power supply may be another form of charge
storage device, such as a capacitor. The power supply may require recharging and may
have a capacity that allows for the storage of enough energy for one or more user
operations, for example one or more aerosol-generating experiences. For example, the
power supply may have sufficient capacity to allow for continuous heating of an aerosol-forming
substrate for a period of around six minutes, corresponding to the typical time taken
to smoke a conventional cigarette, or for a period that is a multiple of six minutes.
In another example, the power supply may have sufficient capacity to allow for a predetermined
number of puffs or discrete activations of the heater.
[0260] Specific embodiments will now be described with reference to the figures, in which:
Figure 1 is a schematic cross-sectional diagram of an embodiment of an aerosol-generating
system in accordance with the present disclosure;
Figure 2 is a schematic cross-sectional diagram of an embodiment of an aerosol-generating
article in accordance with the present invention;
Figure 3 is a schematic cross-sectional diagram of an embodiment of an aerosol-generating
system in accordance with the present disclosure; and
Figure 4 is a schematic cross-sectional diagram of a comparative example of an aerosol-generating
system.
[0261] Figure 1 illustrates an aerosol-generating system 100 comprising an aerosol-generating
device 10 and an aerosol-generating article 1. The aerosol-generating device 10 comprises
a housing 4, extending between a mouth end 2 and a distal end (not shown). The housing
4 comprises a peripheral wall 6. The peripheral wall 6 defines a device cavity for
receiving an aerosol-generating article 1. The device cavity is defined by a closed,
distal end and an open, mouth end. The mouth end of the device cavity is located at
the mouth end of the aerosol-generating device 10. The aerosol-generating article
1 is configured to be received through the mouth end of the device cavity and is configured
to abut the closed end of the device cavity. The length of the device cavity is about
25 mm.
[0262] An air-flow channel 5 is defined within the peripheral wall 6. The air-flow channel
5 extends between an inlet 7 located at the mouth end of the aerosol-generating device
10 and outlet 9 located at a distal position along the peripheral wall 6.
[0263] The aerosol-generating device 10 further comprises a heater (not shown) and a power
source (not shown) for supplying power to the heater. A controller (not shown) is
also provided to control such supply of power to the heater. The heater is configured
to heat the aerosol-generating article 1 during use, when the aerosol-generating article
1 is received within the device 10.
[0264] The aerosol-generating article 1 comprises a first air ingress zone 15 and a second
air ingress zone 115 located along the wrapper 22.
[0265] The first air ingress zone 15 is located about 2 mm downstream of the upstream end
of the rod of aerosol-forming substrate 12. The second air ingress zone 115 is located
about 2 mm downstream of the upstream end of the hollow support segment 14 and about
2 mm downstream of the downstream end of the rod of aerosol-forming substrate 12,
given that the rod of aerosol-forming substrate 12 and the hollow support segment
14 are in direct abutment. Thus, the two air ingress zones 15, 115 are located along
and around two different components of the aerosol-generating article 1.
[0266] As shown in Figures 1 and 2, the first and second air ingress zones 15, 115 each
comprise a line of perforations extending around the article 1 and through the wrapper
22. The second air ingress zone 115 extends through the peripheral wall of the hollow
support segment 14.
[0267] When the aerosol-generating article 1 is received within the device cavity, the outlet
9 is configured to align or overlie the first air ingress zone 15. Once received within
the device cavity, the upstream end of the aerosol-generating article 1 is arranged
to abut the closed end of the device cavity such that air being drawn through the
aerosol-generating device 10 may not flow through the upstream end of the aerosol-generating
article 1. Air being drawn through the aerosol-generating device 10 may only enter
the aerosol-generating article 1 through the first and second air ingress zones 15,
115, as shown in Figure 1.
[0268] The air-flow channel 5 is defined along the inner surface of the peripheral wall
6. In such embodiments, a portion of the air-flow channel 5 is configured to overlie
the first and second air ingress zones 15, 115 of the aerosol-generating article 1.
The air-flow channel 5 has a length of about 23 millimetres. In such an embodiment,
shown in Figure 1, the entire length of the air-flow channel 5 is configured to overlie
the aerosol-generating article 1 when received within the device 10.
[0269] Figure 2 displays the aerosol-generating article 1, which is configured to be used
in the aerosol-generating system 100 shown in Figure 1.
[0270] The aerosol-generating article 1 comprises a rod of aerosol-forming substrate 12,
a hollow support segment 14, an aerosol-cooling element (or segment) 16 and a mouthpiece
segment 18. The components (in this case, the hollow support segment 14, the aerosol-cooling
element 16 and the mouthpiece segment 18) downstream of the rod of aerosol-forming
substrate 12 form the downstream section of the aerosol-generating article 1. These
four elements are arranged in an end-to-end, longitudinal alignment and are circumscribed
by a wrapper 22 to form the aerosol-generating article 1. The aerosol-generating article
1 shown in Figure 1 is particularly suitable for use with an electrically operated
aerosol-generating device 1 comprising a heater for heating the rod of aerosol-forming
substrate 12.
[0271] The rod of aerosol-forming substrate 12 has a length of about 12 millimetres and
a diameter of about 7 millimetres. The rod 12 is cylindrical in shape and has a substantially
circular cross-section. The rod 12 comprises a gathered sheet of homogenised tobacco
material. The hollow cellulose acetate tube (hollow support segment) 14 has a length
of about 8 millimetres and its peripheral wall has a thickness of 1 millimetre.
[0272] The mouthpiece segment 18 comprises a plug of cellulose acetate tow of 8 denier per
filament and has a length of about 7 millimetres. The mouthpiece segment 18 has a
diameter of about 7 millimetres. The aerosol-cooling element 16 has a length of about
18 millimetres and a diameter of about 7 millimetres.
[0273] As discussed above, the aerosol-generating article 1 comprises a first air ingress
zone 15 provided along the rod of aerosol-forming substrate, at least about 2 millimetres
from an upstream end of the rod of aerosol-forming substrate 12. The first air ingress
zone 15 is located less than 10 millimetres from the downstream end of the rod of
aerosol-forming substrate 12, or upstream end of the hollow support segment 14. The
first and second air ingress zones 15, 115 circumscribe the aerosol-generating article
1. That is, the first and second air ingress zones 15, 115 surround the entire periphery
of the aerosol-generating article 1.
[0274] Figure 3 shows an aerosol-generating system 200 similar to aerosol-generating system
100. The aerosol-generating system 200 comprises an aerosol-generating device 20 and
the aerosol-generating article 1, both configured to be used with each other. The
aerosol-generating device 20 is similar to aerosol-generating device 10, but differs
in that the device 20 comprises an air-flow channel 205 comprising one inlet 7 and
two outlets 9, 19. A first outlet 9 of the air-flow channel 205 is configured to provide
fluid communication between the exterior of the aerosol-generating device 20 and a
first air ingress zone 15 of the aerosol-generating article 1. A second outlet 19
of the air-flow channel 205 is configured to provide fluid communication between the
exterior of the aerosol-generating device 20 and a second air ingress zone 115 of
the aerosol-generating article 1. The first outlet 9 is configured to overlie (or
overlap) the first air ingress zone 15 when the article 1 is received within the device
20 and the second outlet 19 is configured to overlie (or overlap) the second air ingress
zone 115 when the article 1 is received within the device 20. The spacing or distance
between the first and second outlets 9,19 can be equivalent to the distance between
the first and second air ingress zones 15, 115.
[0275] As shown in Figures 1 & 3, fluid communication between the exterior of the aerosol-generating
devices 10, 20 and the interior of the aerosol-generating article 1 is established
via two different air ingress zones 15, 115. However, the first air ingress zone 15
is configured to be able to allow the passage of more air than the second air ingress
zone 115. In other words, the first air ingress zone 15 is configured to provide a
greater level of air ingress than the second air ingress zone 115.
[0276] The first air ingress zone 15 is configured to be the primary air intake zone of
the aerosol-generating article 1 when the article 1 is received within the device
10, 20 when an abutment of the upstream end of the article 1 with the distal end of
the device cavity occurs. The second air ingress zone 115 is configured to provide
ventilation to the article 1; that is, ventilating air to aerosol flowing from the
rod of aerosol-forming substrate 12 through the hollow support segment 14 towards
the mouth end of the article 1.
[0277] When received within the aerosol-generating device 10, 20, the open, upstream end
of the aerosol-generating article 1 abuts the distal end of the device cavity in order
to prevent air flowing through the upstream end of the aerosol-generating article
1. Therefore, during use, most of the air flowing through the air-flow channel 5,
205 is configured to flow through the first air ingress zone 15 due to the overlap
between the air-flow channel outlet 9 and the first air ingress zone 15.
[0278] Figure 4 shows a comparative example of an incompatible aerosol-generating article
103, which does not have a first air ingress zone located around the rod of aerosol-forming
substrate, being used with the aerosol-generating device 10. Owing to the fact that
the article 103 does not have an air ingress zone and that the upstream end of the
article 103 is in abutment with the distal end of the device cavity, air cannot be
drawn through the article 103.
[0279] The aerosol-generating device 10 comprises an annular air-flow channel 5, as shown
in Figure 1. The aerosol-generating device 20, as shown in Figure 3, comprises at
least two elongate air-flow channels 205.