U.S. patent application number 16/969415 was filed with the patent office on 2021-02-25 for aerosol generating article with retractable heat source.
The applicant listed for this patent is PHILIP MORRIS PRODUCTS S.A.. Invention is credited to David Kuchen, Alessandra Primo.
Application Number | 20210052011 16/969415 |
Document ID | / |
Family ID | 1000005207764 |
Filed Date | 2021-02-25 |
United States Patent
Application |
20210052011 |
Kind Code |
A1 |
Kuchen; David ; et
al. |
February 25, 2021 |
AEROSOL GENERATING ARTICLE WITH RETRACTABLE HEAT SOURCE
Abstract
An aerosol generating article (100) having a proximal end (102)
and a distal end (104), comprising an inner tubular element (105)
having a mouthpiece end (107) and an opposed heat source end
positioned at the distal end of the aerosol generating article, and
an outer tubular element (130) extending from the proximal end of
the aerosol generating article towards the distal end thereof. The
inner tubular element comprises an inner wrapping sheet (109)
circumscribing, in a co-axial arrangement: a combustible heat
source (115) positioned towards the distal end of the aerosol
generating article; an aerosol-forming substrate (120) downstream
of the combustible heat source; and, typically, a void space (125)
between the aerosol-forming substrate and the mouthpiece end. The
outer tubular element typically circumscribes at least the
mouthpiece end of the inner tubular element and the void space and
terminates downstream of the heat source. The inner wrapping sheet
includes a pre-twisted portion (109b) at least in the region
circumscribing the void space. The arrangement provides that the
distal end including the combustible heat source and the
aerosol-forming substrate is readily slideable relative to the
outer tubular element from an extended position having a first
article length (L1), to a retracted position having a second
article length (L2) that is less than the first article length and
in which the void space is at least partially collapsed to an
axially contracted configuration.
Inventors: |
Kuchen; David;
(Vallamand-Dessous, CH) ; Primo; Alessandra;
(Cormondreche, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PHILIP MORRIS PRODUCTS S.A. |
Neuchatel |
|
CH |
|
|
Family ID: |
1000005207764 |
Appl. No.: |
16/969415 |
Filed: |
January 29, 2019 |
PCT Filed: |
January 29, 2019 |
PCT NO: |
PCT/EP2019/052073 |
371 Date: |
August 12, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A24D 3/17 20200101; A24F
42/80 20200101; A24F 42/60 20200101 |
International
Class: |
A24F 42/60 20060101
A24F042/60; A24F 42/80 20060101 A24F042/80; A24D 3/17 20060101
A24D003/17 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 16, 2018 |
EP |
18157252.0 |
Claims
1. An aerosol generating article having a proximal end and a distal
end, comprising: an inner tubular element comprising an inner
wrapping sheet circumscribing, in a co-axial arrangement: a
combustible heat source positioned towards the distal end of the
aerosol generating article; and an aerosol-forming substrate
downstream of the combustible heat source; and an outer tubular
element circumscribing at least a portion of the inner tubular
element; wherein the inner wrapping sheet includes a pre-twisted
portion; whereby the pre-twisted portion enables deformation of the
inner tubular element so that the distal end of the inner tubular
element is slideable relative to the outer tubular element.
2. The aerosol generating article according to claim 1, further
comprising a mouthpiece filter at the proximal end, wherein a
mouthpiece end of the inner tubular element is mounted to the
mouthpiece filter.
3. The aerosol generating article according to claim 2, further
comprising a void space between the aerosol-forming substrate and
the mouthpiece end.
4. The aerosol generating article according to claim 3, wherein the
outer tubular element extends from the proximal end of the aerosol
generating article towards the distal end thereof, and
circumscribes at least the mouthpiece end of the inner tubular
element and the void space and terminates downstream of the heat
source, and wherein the pre-twisted portion is at least in the
region circumscribing the void space.
5. The aerosol generating article according to claim 3, wherein the
inner tubular element is slideable from an extended position having
a first article length, to a retracted position having a second
article length that is less than the first article length and in
which the void space is at least partially collapsed to an axially
contracted configuration.
6. The aerosol generating article according to claim 5, wherein the
second article length is about 90% or less than the first article
length, or about 80% or less than the first article length, or
about 70% or less than the first article length.
7. The aerosol generating article according to claim 2, wherein the
outer tubular element comprises an outer wrapping sheet joined to
the inner tubular element only at the mouthpiece end thereof for a
first circumferential wrap and joined to itself for a second
wrap.
8. The aerosol generating article according to claim 7, wherein the
outer wrapping sheet is joined to itself along substantially the
whole length thereof for the second wrap.
9. The aerosol generating article according to claim 1. wherein a
portion of the inner tubular element downstream of pre- twisted
portion is rotationally offset relative to a portion of the inner
tubular element upstream of pre-twisted portion by about 5 degrees
or more, or about 15 degrees or more, or about 45 degrees or
more.
10. A method of manufacturing an aerosol generating article having
a proximal end and a distal end, comprising: providing an inner
tubular element comprising an inner wrapping sheet circumscribing,
in a co-axial arrangement: a combustible heat source positioned
towards the distal end of the aerosol generating article; and an
aerosol-forming substrate downstream of the combustible heat
source; wherein the inner wrapping sheet includes a pre-twisted
portion; and overwrapping at least a portion of the inner tubular
element with an outer wrapping sheet, whereby the pre-twisted
portion enables deformation of the inner tubular element so that
the distal end of the inner tubular element is slideable relative
to the outer tubular element.
11. The method of claim 10, wherein overwrapping the outer wrapping
sheet comprises, starting from a first edge of the outer wrapping
sheet, adhesively joining the outer wrapping sheet to the inner
tubular element only at a mouthpiece end thereof for a first
circumferential wrap and adhesively joining the first wrap and a
second wrap of the outer wrapping sheet along substantially the
whole length of the outer wrapping sheet, thereby forming an outer
tubular element extending from the proximal end of the aerosol
generating article towards the distal end thereof, circumscribing
at least the mouthpiece end of the inner tubular element.
12. The method of claim 10, wherein the pre-twist is applied to the
inner tubular element during the overwrapping procedure.
13. The method of claim 12, wherein the overwrapping procedure
comprises applying the outer wrapping sheet using a rotating
drum.
14. The method of claim 13, wherein the overwrapping comprises
rolling the inner tubular element through a pinch between the
rotating drum on which the sheet is temporarily attached and a
stationary guide plate, the sheet wrapping around the inner tubular
element and adhering thereto during passage through the pinch,
wherein the distal end of the inner element that is not overwrapped
rotates at a different rate to the more proximal end thereof
circumscribed by the outer wrapping sheet, thereby inducing the
twist in the inner wrapping sheet of the inner tubular element.
15. The method of claim 10, comprising manufacturing a pair of
aerosol generating articles back-to-back, including providing a
singular mouthpiece filter element having first and second ends
corresponding to initially conjoined first and second mouthpiece
filters, wherein providing an inner tubular element comprises
providing first and second inner tubular elements which are mounted
to the respective first and second ends of the singular mouthpiece
filter element, wherein the overwrapping of the first and second
inner tubular elements is simultaneous, using a single outer
wrapping sheet symmetrical about the centre of the mouthpiece
filter element to form initially conjoined first and second outer
tubular elements, the method including cutting through the
conjoined outer tubular elements and the mouthpiece filter element
to separate the conjoined articles into first and second aerosol
generating articles.
Description
[0001] This invention relates to an aerosol generating article with
a retractable heat source for heating an aerosol-forming
substrate.
[0002] Aerosol generating articles in which tobacco is heated
rather than burned have been proposed in the art. An aim of such
`heated` aerosol generating articles is to reduce certain smoke
constituents of the type produced by the combustion and pyrolytic
degradation of tobacco in conventional cigarettes. In one known
type of heated aerosol generating article, an aerosol is generated
by a combustible heat source transferring heat to an
aerosol-forming substrate, for example containing tobacco. The
aerosol-forming substrate may be located downstream of the
combustible heat source. An outer wrapping sheet of the aerosol
generating article may be used to enclose the aerosol-forming
substrate and at least a portion of the combustible heat source.
During use, volatile compounds are released from the
aerosol-forming substrate by heat transfer from the combustible
heat source and entrained in air drawn through the heated aerosol
generating article from a tip end where the heat source is located
to a mouthpiece end. As the released compounds cool, they condense
to form an aerosol.
[0003] As the combustible heat source is difficult to extinguish
and may burn for longer than the time for the aerosol-forming
substrate to deplete, it is desirable to provide an aerosol
generating article that can cover the combustible heat source to
dispose of the aerosol generating article. Arranging the outer
wrapping sheet to include an internal recess into which the
combustible heat source can be drawn is one way of achieving this.
Incorporating a series of holes to create areas of weakness in the
aerosol generating article to aid its collapse is also known in the
art. However, this approach introduces additional air paths which
may be detrimental to aerosol delivery.
[0004] WO 2017/115196 discloses an aerosol generating article
having a collapsible structure to retract the heat source into an
interior `void space`. The disclosed structure includes an inner
tubular member, which comprises, in order from a distal, tip end
towards a proximal, mouthpiece end: a heat source, an
aerosol-generating substrate, a first diffuser element, a void
space, a second diffuser element, and an aerosol cooling element.
The inner tubular member is retained within a tubular body which
includes a mouthpiece filter element. An outer wrapping sheet may
be adhered at a junction of the inner tubular member with the
tubular body to retain the inner tubular element within the tubular
body. The inner tubular member includes an area of weakness whereby
the tip end can be collapsed within the tubular body into the void
space.
[0005] It would be desirable to provide an aerosol generating
article having a structure incorporating an area of weakness. It
would be desirable to provide an aerosol generating article which
avoided creating alternative air paths which would adversely
aerosol delivery. In addition, it would be desirable to provide an
aerosol generating article that can be manufactured using existing
manufacturing processes and can be produced at existing
manufacturing speeds.
[0006] According to an aspect of the invention, an aerosol
generating article is provided having a proximal end and a distal
end. An inner tubular element is provided, comprising an inner
wrapping sheet circumscribing a combustible heat source positioned
towards the distal end of the aerosol generating article. The inner
wrapping sheet further circumscribes an aerosol-forming substrate
positioned downstream of the combustible heat source. The
combustible heat source and aerosol-forming substrate are provided
in a co-axial arrangement. The aerosol generating article further
comprises an outer tubular element which circumscribes at least a
portion of the inner tubular element. The inner wrapping sheet
includes a pre-twisted portion which enables deformation of the
inner tubular element so that the distal end of the inner tubular
element is slideable relative to the outer tubular element.
[0007] Advantageously, the pre-twisted portion provides a
convenient mechanism for the aerosol generating article to collapse
and can be incorporated into existing manufacturing lines with
little modification and without affecting line speed. A further
advantage of the pre-twisted portion is that the area of weakness
that enables the collapsing deformation is created without
introducing additional air paths.
[0008] In some embodiments, the aerosol generating article may
include a mouthpiece filter at the proximal end and a mouthpiece
end of the inner tubular element may be mounted to the mouthpiece
filter. In some embodiments, the combustible heat source may be a
carbonaceous heat source. The aerosol-forming substrate may
comprise tobacco.
[0009] In some embodiments, the aerosol generating article may
include a void space between the aerosol-forming substrate and the
mouthpiece end. A first transfer element may be located between the
aerosol-forming substrate and the void space in the extended
position. The aerosol generating article may also include a second
transfer element separated from the first transfer element by the
void space in the extended position. Where first and second
transfer elements are provided, these may abut one another when the
void space is collapsed to the axially contracted configuration.
The outer tubular element may extend from the proximal end of the
aerosol generating article towards the distal end thereof, and
circumscribe at least the mouthpiece end of the inner tubular
element and the void space and terminate downstream of the heat
source. The pre-twisted portion may be at least in the region
circumscribing the void space. In certain embodiments where a void
space is included, the inner tubular element is slideable from an
extended position having a first article length, to a retracted
position having a second article length that is less than the first
article length and in which the void space is at least partially
collapsed to an axially contracted configuration. When in the
retracted position, the second article length may be about 80% or
less than the first article length. When in the retracted position,
the second article length may be about 70% or less than the first
article length.
[0010] The outer tubular element may terminate at or downstream of
the aerosol-forming substrate.
[0011] In some embodiments, the outer tubular element may comprise
an outer wrapping sheet. The outer wrapping sheet may be joined to
the inner tubular element only at the mouthpiece end thereof. The
outer wrapping sheet may be joined to the inner tubular element at
the mouthpiece end thereof for a first circumferential wrap. The
outer wrapping sheet may be joined to itself for a second wrap. The
outer wrapping sheet may be joined to itself along substantially
its whole length. The outer wrapping sheet may be joined to the
inner wrapping sheet adhesively. The outer wrapping sheet may be
joined to itself adhesively.
[0012] A portion of the inner tubular element downstream of the
pre-twisted portion may be rotationally offset relative to a
portion of the inner tubular element upstream of the pre-twisted
portion. The rotational offset may be 5 degrees or more. The
rotational offset may be 15 degrees or more. The rotational offset
may be 45 degrees or more. When in the retracted position, the
second article length may be about 90% or less than the first
article length.
[0013] There is also disclosed an outer wrapping sheet for use in
the manufacture of an aerosol generating article. The outer
wrapping sheet comprises first and second opposed edges
substantially parallel with a longitudinal axis of the aerosol
generating article. A width of the sheet is defined by the first
and second opposed edges that is at least equal to twice the
circumference of the inner tubular element. The outer wrapping
sheet has deposited thereon a glue pattern comprising a first
region comprising a band of glue extending substantially
perpendicularly from the first edge towards the second edge. The
band of glue extends from the first edge towards the second edge
for at least a distance equal to the circumference of the inner
tubular element. The band of glue forms an adhesive join between
the outer wrapping sheet and the inner tubular element only at the
mouth piece end thereof when wrapped therearound starting from the
first edge. The glue pattern further comprises a second region
comprising an area of glue extending along substantially the whole
length of the outer wrapping sheet, from the point at which the
band ends to the second edge. The glue pattern in the second region
forms an adhesive join between the first wrap and any subsequent
wraps of the outer wrapping sheet along substantially the whole
length thereof.
[0014] Advantageously, the particular gluing pattern on the outer
wrapping sheet provides both a firm connection of the inner tubular
element to the outer tubular element and an unglued inner region
that allows the inner tubular element to collapse, as well as
structural rigidity surrounding the unglued portion.
[0015] According to an aspect of the invention, there is provided a
method of manufacturing an aerosol generating article having a
proximal end and a distal end. The method comprises providing an
inner tubular element comprising an inner wrapping sheet
circumscribing a combustible heat source positioned towards the
distal end of the aerosol generating article. The inner wrapping
sheet further circumscribes an aerosol-forming substrate downstream
of the combustible heat source. The combustible heat source and
aerosol-forming substrate are provided in a co-axial arrangement.
The inner wrapping sheet includes a pre-twisted portion. The method
further comprises overwrapping at least a portion of the inner
tubular element with an outer wrapping sheet. As a result, the
distal end of the inner tubular element is slideable relative to
the outer tubular element.
[0016] In certain embodiments, the inner wrapping sheet further
circumscribes a void space between the aerosol-forming substrate
and the mouthpiece end, also in co-axial arrangement therewith.
[0017] Overwrapping the inner tubular element may comprise,
starting from a first edge of the outer wrapping sheet, adhesively
joining the outer wrapping sheet to the inner tubular element only
at a mouthpiece end thereof for a first circumferential wrap. The
overwrapping may further comprise a second wrap of the outer
wrapping sheet along substantially the whole length of the outer
wrapping sheet, thereby forming the outer tubular element. The
outer tubular element may extend from the proximal end of the
aerosol generating article towards the distal end thereof. Where
the inner tubular member comprises a void space, the outer tubular
element may circumscribe at least the mouthpiece end of the inner
tubular element and the void space. The outer tubular element may
terminate downstream of the heat source. The distal end including
the combustible heat source and the aerosol-forming substrate may
be slideable relative to the outer tubular element from an extended
position having a first article length, to a retracted position
having a second article length. The second article length is less
than the first article length. Sliding the distal end from an
extended position to a retracted position at least partially
collapses the void space to an axial contracted configuration.
[0018] The method may comprise providing a mouthpiece filter at the
proximal end of the aerosol generating article. The mouthpiece end
of the inner tubular element may be mounted to the mouthpiece
filter.
[0019] The method may comprise applying the pre-twist to the inner
tubular element during the overwrapping procedure. The overwrapping
may comprise applying the outer wrapping sheet using a rotating
drum, which may comprise rolling the inner tubular element through
a pinch between the rotating drum on which the outer wrapping sheet
is temporarily attached and a stationary guide plate, the outer
wrapping sheet wrapping around the inner tubular element and
adhering thereto during passage through the pinch. The distal end
of the inner tubular element that is not overwrapped may rotate at
a different rate to the more proximal end thereof circumscribed by
the outer wrapping sheet, thereby inducing the twist in the inner
wrapping sheet of the inner tubular element. The pre-twist may be
applied to the inner tubular element at a twisting station prior to
the overwrapping procedure.
[0020] The method may comprise manufacturing a pair of aerosol
generating articles back-to-back, including providing a singular
mouthpiece filter element having first and second ends
corresponding to initially conjoined first and second mouthpiece
filters. The method may comprise providing an inner tubular element
comprising providing first and second inner tubular elements which
are mounted to the respective first and second ends of the singular
mouthpiece filter element. The overwrapping of the first and second
inner tubular elements may be simultaneous. The overwrapping may
use a single outer wrapping sheet. The outer wrapping sheet may be
symmetrical about the centre of the mouthpiece filter element. The
outer wrapping sheet may form initially conjoined first and second
outer tubular elements. The method may include cutting through the
conjoined outer tubular elements and the mouthpiece filter element
to separate the conjoined articles into first and second aerosol
generating articles.
[0021] All scientific and technical terms used herein have meanings
commonly used in the art unless otherwise specified. The
definitions provided herein are to facilitate understanding of
certain terms used frequently herein.
[0022] As used herein, the term "aerosol generating article" refers
to an article comprising an aerosol forming substrate that is
capable of releasing volatile compounds that can form an aerosol,
for example by heating, combustion or chemical reaction.
[0023] As used herein, the term "aerosol forming substrate" is used
to describe a substrate capable of releasing volatile compounds,
which can form an aerosol. The aerosols generated from the aerosol
forming substrates of aerosol generating articles according to the
invention may be visible or invisible and may include vapours (for
example, fine particles of substances, which are in the gaseous
state, that are ordinarily liquid or solid at room temperature) as
well as gases and liquid droplets of condensed vapours.
[0024] As used herein, the term "sheet" denotes a laminar element
having a width and length greater than the thickness thereof.
[0025] The terms "upstream" and "downstream" refer to relative
positions of elements of the aerosol generating article described
in relation to the direction of inhalation air flow as it is drawn
through the body of the aerosol generating article from a distal,
tip end to the mouthpiece end. In other words as used herein,
"downstream" is defined relative to air flow during use of the
smoking article or aerosol generating article, with the mouthpiece
end of the article being the downstream end through which air and
aerosol is drawn. The end opposite the mouthpiece end is the
upstream end.
[0026] The words "preferred" and "preferably" refer to embodiments
of the invention that may afford certain benefits, under certain
circumstances. However, other embodiments may also be preferred,
under the same or other circumstances. Furthermore, the recitation
of one or more preferred embodiments does not imply that other
embodiments are not useful, and is not intended to exclude other
embodiments from the scope of the disclosure, including the
claims.
[0027] Throughout the description and claims of this specification,
the words "comprise" and "contain" and variations of them mean
"including but not limited to", and they are not intended to (and
do not) exclude other moieties, additives, components, integers or
steps. Throughout the description and claims of this specification,
the singular encompasses the plural unless the context otherwise
requires. In particular, where the indefinite article is used, the
specification is to be understood as contemplating plurality as
well as singularity, unless the context requires otherwise.
[0028] FIG. 1 is a schematic diagram of an exemplary aerosol
generating article;
[0029] FIG. 2A and 2B are schematic diagrams of the exemplary
aerosol generating article of FIG. 1 in extended and retracted
positions respectively;
[0030] FIG. 3 is a schematic diagram of first and second conjoined
inner tubular elements before overwrapping by an outer wrapping
sheet;
[0031] FIG. 4 is a schematic diagram of conjoined aerosol
generating articles before separation into first and second aerosol
generating articles;
[0032] FIG. 5 is a schematic side view of the overwrapping of inner
tubular elements by an outer wrapping sheet at an overwrap station;
and
[0033] FIG. 6 is a schematic diagram of a partially wrapped inner
tubular element.
[0034] The schematic drawings are not necessarily to scale and are
presented for purposes of illustration and not limitation. The
drawings depict one or more aspects described in this disclosure.
However, it will be understood that other aspects not depicted in
the drawings fall within the scope of this disclosure.
[0035] FIG. 1 is a schematic diagram of an exemplary aerosol
generating article 100 extending between a proximal end 102 and a
distal end 104. An inner tubular element 105 having a mouthpiece
end 107 is provided in the aerosol generating article 100. Also
provided is an opposed heat source end positioned at the distal end
104 of the aerosol generating article 100. The inner tubular
element 105 comprises an inner wrapping sheet 109. The inner
wrapping sheet 109 circumscribes a combustible heat source 115
positioned towards the distal end of the aerosol generating article
100. The inner wrapping sheet 109 further circumscribes an
aerosol-forming substrate 120 positioned downstream of the
combustible heat source 115. The inner wrapping sheet 109 further
circumscribes a void space 125 located between the aerosol-forming
substrate 120 and the mouthpiece end 107. The combustible heat
source 115, aerosol-forming substrate 120 and void space 125 are
provided in a co-axial arrangement. The aerosol generating article
100 further comprises an outer tubular element 130 extending from
the proximal end 102 of the aerosol generating article 100 towards
the distal end 104 thereof. The outer tubular element 130
circumscribes at least the mouthpiece end 107 of the inner tubular
element 105 and the void space 125. The outer tubular element 130
terminates downstream of the heat source 115. The inner wrapping
sheet 109 includes a pre-twisted portion 109b in at least in the
region circumscribing the void space 125 (see FIG. 6). The distal
end 104 including the combustible heat source 115 and the
aerosol-forming substrate 120 is slideable relative to the outer
tubular element 130 from an extended position having a first
article length (L1, see FIG. 2A), to a retracted position having a
second article length less than the first article length (L2, see
FIG. 2B). Sliding the distal end 104 from an extended position to a
retracted position at least partially collapses the void space 125
to an axially contracted configuration.
[0036] The aerosol generating article 100 is also shown comprising
first 121a and second 121b transfer elements located within the
inner tubular element 105 (see FIG. 2A). The first 121a and second
121b transfer elements may be spaced from one another when the
aerosol generating article is in the extended position. The first
121a and second 121b transfer elements are shown located at the
ends of the void space 125, between the aerosol-forming substrate
120 and the mouthpiece filter 127 respectively. The aerosol
generating article 100 is also shown comprising a transfer element
117 located between the combustible heat source 115 and the
aerosol-forming substrate 120. The transfer element 117 is
circumscribed within the inner wrapping sheet 109.
[0037] As shown in FIG. 6, the pre-twisted portion 109b of the
inner wrapping sheet 109 may circumscribe part of respective first
121a and second 121b transfer elements. To extinguish the
combustible heat source 115, the distal end 104 including the
combustible heat source 115 and the aerosol-forming substrate 120
is slideable relative to the outer tubular element 130. The distal
end is slideable from an extended position having a first article
length (L1 in FIG. 2A), to a retracted position having a second
article length (L2 in FIG. 2B) less than the first article length,
as shown in FIG. 2A and 2B. In the retracted position, the void
space 125 is at least partially collapsed to an axially contracted
configuration. The axially contracted configuration may be caused
by application of a pressure or force at the distal end of the
aerosol generating article 100, such as when an aerosol generating
article 100 is "stubbed out". It is not essential that the void
space 125 be entirely collapsed. While the transfer elements 121a,
121b are separated in the extended position, in some cases it may
be desirable to keep the transfer elements 121a, 121b separated
when the aerosol generating article 100 is in the contracted
position, such as shown in FIG. 2B. In other cases, it may be
desirable that the first 121a and second 121b transfer elements
abut one another when the void space 125 is collapsed to the
axially contracted configuration (not shown). It would be apparent
to the skilled person that the first 121a and second 121b transfer
elements are not essential features; for example, the void space
may be bounded distally by the aerosol-forming substrate 120, and
proximally by the mouthpiece filter 127. Indeed, the void space 125
itself is not essential. It will be understood that any axially
compressible structure within the inner tubular element would
enable the distal end of the inner tubular element to be slideable
relative to the outer tubular element for "stubbing out" the
aerosol generating article 100.
[0038] The pre-twisted portion 109b is a preferred method of
creating an area of weakness, to enable the distal end of the inner
tubular element to be slideable relative to the outer tubular
element, in particular over perforating or cutting slits into the
inner wrapping sheet, as the pre-twisted portion does not introduce
additional air paths within the aerosol generating article 100.
Preferably, aerosol generating articles 100 are manufactured on a
back-to-back basis, such as shown in FIGS. 3 and 4. That is to say,
two aerosol generating articles 100, 100' are created integrally
and simultaneously before being separated by cutting through the
conjoined articles centrally. FIG. 3 illustrates first 105 and
second 105' inner tubular elements before being overwrapped by an
outer wrapping sheet 135. In the back-to-back configuration, a
single mouthpiece filter element 129 can be considered to have
first and second ends which correspond to initially conjoined first
127 and second 127' mouthpiece filters which are mounted to the
respective proximal ends 102, 102' of first 105 and second 105'
inner tubular elements. The first 127 and second 127' mouthpiece
filters are located downstream of the respective associated void
space 125, 125'. This advantageously allows for simultaneous
overwrapping of the first 105 and second 105' inner tubular
elements using a single outer wrapping sheet comprising initially
conjoined outer wrapping sheets 135, 135' that are symmetric about
the centre line 200 of the mouthpiece filter element 129 to form
initially conjoined first 130 and second 130' outer tubular
elements. Once formed, the conjoined aerosol generating articles
100, 100' can be separated by cutting through the conjoined outer
tubular elements 130, 130' and the mouthpiece filter element
129.
[0039] The co-axial arrangement of the inner tubular element 105 is
best shown in FIG. 1. Inner tubular element 105 has a mouthpiece
end 107 and a heat source end and comprises an inner wrapping sheet
109 circumscribing, in a co-axial arrangement, a combustible heat
source 115 positioned towards the distal end 104 of the aerosol
generating article 100; an aerosol-forming substrate 120 downstream
of the combustible heat source 115 and a void space 125 between the
aerosol-forming substrate 120 and the mouthpiece end 107. The inner
wrapping sheet 109 includes a pre-twisted portion 109b at least in
the region circumscribing the void space 125. The inner tubular
element 105 is also shown comprising a cap 110 at the distal end
104, upstream of the combustible heat source 115. The cap 110 is
shown abutting the combustible heat source 115 and is circumscribed
by a portion of the inner wrapping sheet 109. The removable cap 110
may comprise a desiccant, such as glycerine, to absorb moisture.
This prolongs the longevity of the components within the inner
tubular element 105. The removable cap 110 may be removed by
twisting the removable cap 110 to break the portion of the inner
wrapping sheet 109 adjacent to the cap. Removal of the removeable
cap 110 exposes a front portion of the combustible heat source 115
enabling the ignition the combustible heat source 115. The
combustible heat source 115 may be a carbonaceous heat source. The
aerosol- forming substrate 120 may comprise tobacco.
[0040] The outer wrapping sheet 135 comprises first 155a and second
155b opposed edges, substantially parallel with a longitudinal axis
150 of the aerosol generating article 100. The longitudinal axis
150 of the aerosol generating article 100 extends between the
proximal 102 and distal 104 ends of the aerosol generating article
100. The first 155a and second 155b opposed edges define
therebetween a width of the outer wrapping sheet 135. The width of
the outer wrapping sheet 135 is at least equal to twice the
circumference of an inner tubular element 105 that it is to
circumscribe so that it can wrap around at least twice. Extending
perpendicularly between the first 155a and second 155b edges are
the proximal 102 and distal 103 ends of the outer wrapping sheet
135. It will be understood that when a pair of aerosol generating
articles 100 are manufactured back-to-back with an initially
conjoined outer wrapping sheet, that the respective proximal ends
102, 102' will be conjoined at the centre line 200. For simplicity,
the remaining description will be in respect of the outer wrapping
sheet 135 only. The outer wrapping sheet 135' is an identical
mirror image and like parts are referenced by like reference signs,
but suffixed with a prime (').
[0041] The outer wrapping sheet 135 is shown having an exemplary
glue pattern. The glue pattern shown in FIG. 3 comprises a band of
glue in the form of first 145a and second 145b strips of glue
extending substantially perpendicularly from the first edge 155a
towards the second edge 155b for at least a distance equal to the
circumference of the inner tubular element 105. The first strip of
glue 145a forms an adhesive join between the outer wrapping sheet
135 and the inner tubular element 105, in the region of and
circumscribing the second transfer element 121b. The adhesive join
is thus formed only at the mouthpiece end 107 thereof when wrapped
therearound starting from the first edge 155a. The second strip of
glue 145b, similar to the first strip 145a, but more proximally
located, is used to join the outer wrapping sheet 135 to a
mouthpiece filter 127. The first 145a and second 145b strips form a
band of glue that allows the outer wrapping sheet 135 to be bonded
to the inner tubular element 105 and mouthpiece filter 127 only at
the mouthpiece end 107. While two discrete strips 145a, 145b are
shown, it would be appreciated that other glue arrangements, such
as a single strip and non-continuous droplets or lines are included
by this description.
[0042] The glue pattern is shown further comprising a second region
comprising an area of glue 140 extending along substantially the
whole length of the outer wrapping sheet 135 (i.e. from the
proximal end 102 to the distal end 103), from the point at which
the band 145a, 145b ends to the second edge 155b. The area of glue
140 forms an adhesive join between the first wrap and any
subsequent wraps of the outer wrapping sheet 135 along
substantially the whole length thereof. While adhesives are
described, other methods in the art of joining the outer tubular
element 130 to the inner tubular element 105 or to itself are
included in this description. For example, perforations between the
sheets or use of tightening bands may be similarly effective.
[0043] While the outer tubular element 130 of the aerosol
generating article is shown terminating downstream of the
aerosol-forming substrate 120, it would be apparent to the skilled
person that such an arrangement is purely exemplary and that
arrangements where the outer tubular element 130 terminated at the
aerosol-forming substrate 120 would be equally included by this
description.
[0044] The aerosol generating article 100 may have a length and
diameter similar to a conventional cigarette. The second article
length, L2, may be about 90% or less than the first article length.
The second article length may be about 80% or less than the first
article length. The second article length may be about 70% or less
than the first article length.
[0045] The pre-twisted portion 109b of the inner tubular element
105 may comprise a rotational offset between a portion of the inner
tubular element upstream of the pre-twisted portion 109b
(subsequently referred to as the "upstream portion") and a portion
of the inner tubular element downstream of the pre-twisted portion
(subsequently referred to as the "downstream portion"). The
rotational offset between the upstream and downstream portions of
the inner tubular element may be about 5 degrees or more. The
rotational offset between the upstream and downstream portions of
the inner tubular element may be about 15 degrees or more. The
rotational offset between the upstream and downstream portions of
the inner tubular element may be about 45 degrees or more. The
pre-twisted portion can be identified by a series of helical
grooves and depressions formed in the inner wrapping sheet
circumferentially disposed about the inner tubular member. When
unwrapped, the series of helical grooves and depressions would
comprise a corresponding series of substantially parallel diagonal
lines in the inner wrapping sheet.
[0046] FIG. 5 is a side view of the manufacturing station used to
apply the pre-twisted portion 109b. The overwrapping station
illustrated comprises a first rotating drum 220, on which a series
of outer wrapping sheets 135 with the glue pattern applied is
temporarily attached, for example by the application of a vacuum
holding an unglued side of each sheet 135 to an outer surface of
the first rotating drum 220. Each outer wrapping sheet 135 is
adhered, at the first edge 155a thereof, to an inner tubular
element 105. As the first rotating drum 220 rotates, each inner
tubular element 105 is brought, with outer wrapping sheet 135
attached, in turn towards a stationary guide plate 230. The first
rotating drum 220 and stationary guide plate 230 act as a pinch 210
and friction between the unwrapped aerosol generating article,
stationary guide plate 230 and first rotating drum 220 cause the
outer wrapping sheet 135 to wrap around the inner tubular element
105 thereby forming a wrapped aerosol generating article 100.
[0047] The glue pattern shown in FIG. 3 enables the outer wrapping
sheet 135 to adhere to the inner tubular element 105 and the
mouthpiece filter 127 in a first circumferential wrap. As the outer
wrapping sheet 135 wraps around the inner tubular element 105, the
band of glue comprising first 145a and second 145b strips of glue
bond the outer wrapping sheet 135 to the mouthpiece filter 127 and
the inner tubular element 105 at the mouthpiece end 107. As the
upstream portion of the inner tubular element 105 is not
overwrapped--because the distal end 103 of the outer wrapping sheet
135 terminates more proximally--it rotates at a different rate to
the downstream portion of the inner tubular element 105, which
induces the twist in the inner wrapping sheet 109 of the inner
tubular element 105. The difference in thickness between the
portions of the inner tubular element 105 that are circumscribed by
the outer wrapping sheet 135 and those portions that are not
generates different amounts of friction. This difference in
friction causes the portion of the inner tubular element without
any outer wrapping sheet 135 wrapped around to rotate less than the
portion that is circumscribed by the outer wrapping sheet 135, thus
creating the pre-twisted portion 109b that is readily
collapsible.
[0048] Once the desired amount of twist has been achieved, the
outer wrapping sheet 135 wraps around the inner tubular element 105
for a second circumferential wrap. During the second
circumferential wrap, the outer wrapping sheet 135 is wrapped
around the unglued portion of the inner tubular element 105. The
second region 140 of glue results in the second circumferential
wrap of the outer wrapping sheet 135 forming an outer tubular
element 130 that is rigid, but remains readily collapsible.
[0049] After the outer wrapping sheet 135 has circumscribed itself
a second time, the aerosol generating article 100 is formed and may
be removed from the pinch 210 by a second rotating drum 240. While
it is preferable to apply the pre-twist to the inner tubular
element 105 simultaneously when overwrapping the inner tubular
element 105, it would be apparent to the skilled person this is not
essential. The pre-twist may be applied at a twisting station prior
to the overwrapping station.
[0050] While the manufacturing process has been described in the
context of a single aerosol generating article 100, it would be
apparent to the skilled person that this description would apply
mutatis mutandis to aerosol generating articles manufactured in the
back-to-back configuration, which may be preferable for process
efficiency, being able to produce two articles 100, 100'
simultaneously within a single manufacture line. When manufacturing
aerosol generating articles in the back-to-back configuration, the
rolled article that is removed from the pinch 210 by the second
rotating drum 240 will comprise conjoined outer tubular elements
130, 130'. In this case, the rolled article can be divided along
the centre line 200 by cutting through the conjoined outer tubular
elements 130, 130' and conjoined mouthpiece filter member 129 to
result in first 100 and second 100' aerosol generating articles.
This cutting procedure can be performed as part of the overwrapping
process, or at a separate cutting station.
[0051] While a mouthpiece filter 127 and mouthpiece filter member
129 have been included in this description, they are not essential
to the present invention. Similarly, while a removeable cap 110 has
been described as a way of preserving the aerosol-forming
substrate, a removeable cap 110 is not essential to the present
invention. Similarly, while a transfer element 117 has been
described, it is not essential to the present invention. Further,
while the pre-twisted portion 109b has been described as preferably
formed simultaneously during the overwrapping of the inner tubular
element 105, this is not essential to the invention. The
pre-twisted portion 109b of the inner wrapping sheet 109 may be
applied at a separate twisting station and subsequently
overwrapped. While an adhesive has been described as a method of
securing the outer wrapping sheet 135 to the inner tubular element
105 and to itself, this is not essential to the invention and other
methods of fixation, including methods of mechanical fixation such
as perforations or surface features, are included in this
description. While the outer wrapping sheet 135 is described as
being adhered to itself along substantially the whole length of the
outer wrapping sheet 135, this is not essential to the invention.
Adhesion along less than the whole length of the outer wrapping
sheet 135 may still provide the benefit of the invention.
[0052] Features, integers, characteristics, compounds, chemical
moieties or groups described in conjunction with a particular
aspect, embodiment or example of the invention are to be understood
to be applicable to any other aspect, embodiment or example
described herein unless incompatible therewith. All of the features
disclosed in this specification (including any accompanying claims,
abstract and drawings), and/or all of the steps of any method or
process so disclosed, may be combined in any combination, except
combinations where at least some of such features and/or steps are
mutually exclusive. The invention is not restricted to the details
of any foregoing embodiments. The invention extends to any novel
one, or any novel combination, of the features disclosed in this
specification (including any accompanying claims, abstract and
drawings), or to any novel one, or any novel combination, of the
steps of any method or process so disclosed.
* * * * *