U.S. patent application number 14/006573 was filed with the patent office on 2014-01-23 for smoking article.
This patent application is currently assigned to BRITISH AMERICAN TOBACCO (INVESTMENTS) LIMITED. The applicant listed for this patent is Richard Fiebelkorn. Invention is credited to Richard Fiebelkorn.
Application Number | 20140020698 14/006573 |
Document ID | / |
Family ID | 44012947 |
Filed Date | 2014-01-23 |
United States Patent
Application |
20140020698 |
Kind Code |
A1 |
Fiebelkorn; Richard |
January 23, 2014 |
SMOKING ARTICLE
Abstract
A smoking article comprising a filter section comprising a first
region of filtration material for removing particulate matter from
a smoke stream, wherein the rod the smoking article is arranged to
enhance heat transfer towards the first region of filtration
material is disclosed.
Inventors: |
Fiebelkorn; Richard;
(London, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fiebelkorn; Richard |
London |
|
GB |
|
|
Assignee: |
BRITISH AMERICAN TOBACCO
(INVESTMENTS) LIMITED
London
GB
|
Family ID: |
44012947 |
Appl. No.: |
14/006573 |
Filed: |
March 6, 2012 |
PCT Filed: |
March 6, 2012 |
PCT NO: |
PCT/EP2012/053802 |
371 Date: |
October 8, 2013 |
Current U.S.
Class: |
131/331 |
Current CPC
Class: |
A24D 1/00 20130101; A24D
3/043 20130101; A24D 3/04 20130101; A24D 1/02 20130101 |
Class at
Publication: |
131/331 |
International
Class: |
A24D 3/04 20060101
A24D003/04; A24D 1/00 20060101 A24D001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 22, 2011 |
GB |
1004788.3 |
Claims
1. A smoking article comprising: a filter section comprising a
first region of filtration material for removing particulate matter
from a smoke stream, wherein the smoking article is arranged to
enhance heat transfer towards the first region of filtration
material.
2. A smoking article according to claim 1, further comprising a rod
of smokable material wrapped by a wrapper and arranged to form a
coal at one end thereof when lit, wherein the wrapper has heat
conducting strips attached thereto to enhance heat transfer from
the coal towards the first region of filtration material.
3. A smoking according to claim 2, wherein the rod of smokable
material comprises at least one channel extending therethrough to
enhance heat transfer from the coal towards the first region of
filtration material.
4. A smoking article according to claim 3, wherein the at least one
channel is a plurality of channels disposed radially about the
circumference of the rod of smokable material.
5. A smoking article according to any preceding claim, further
comprising means for cooling the smoke stream downstream of the
first region of filtration material.
6. A smoking article according to claim 5, wherein the means for
cooling the smoke comprises a cooling chamber.
7. A smoking article according to claim 6, further comprising a
region of adsorbent material in or downstream of the cooling
chamber.
8. A smoking article according to any of claims 5 to 7, wherein the
means for cooling the smoke include perforations in a wrapper
circumscribing the filter section.
9. A smoking article according to any one of claims 5 to 7, wherein
the means for cooling the smoke includes at least one gap in the
wrapper circumscribing the filter section.
10. A smoking article according to any preceding claim further
comprising a diluent.
11. A smoking article according to claim 10, wherein the diluent is
adjacently downstream of the first region of filtration
material.
12. A smoking article according to any of claims 2 to 11, wherein
the rod of smokable material comprises a pelletised composite of
tobacco.
13. A smoking article according to any of claims 2 to 12, wherein
the rod of smokable material further comprises carbon.
14. A smoking article according to any preceding claim, wherein the
filter section is configured to alter the composition of the smoke
stream as the smoking article is smoked.
15. A smoking article according to claim 14, wherein the first
region of filtration forms an annulus around a bore which becomes
obstructed as the smoking article is smoked.
16. A smoking article according to any preceding claim, wherein the
filter section is arranged to channel the smoke stream onto the
first region of filtration material.
17. A smoking article according to either claim 15 or claim 16
further comprising a second region of filtration material
downstream of the first region of filtration material, wherein the
second region of filtration material has a filtration efficiency
lower than the filtration efficiency of the first region of
filtration material.
18. A smoking article according to any preceding claim, wherein the
first region of filtration material is wrapped by an insulating
material.
19. A smoking article according to any preceding claim, wherein the
first region of filtration material has a retention value greater
than 30 percent.
20. A smoking article according to any preceding claim, wherein the
first region of filtration material has a retention value greater
than 70 percent.
21. A smoking article according to any preceding claim, wherein the
smoking article is arranged such that the first region of
filtration material only removes matter with boiling points of or
greater than a predetermined level.
22. A smoking article according to claim 21, wherein the
predetermined level is one of about 250.degree. C., 300.degree. C.,
350.degree. C., 400.degree. C., 450.degree. C. or 500.degree. C.
Description
FIELD
[0001] The invention relates to smoking articles and, in
particular, to modifying smoke in smoking articles.
BACKGROUND
[0002] Smoking articles comprising smoke modifying agents are known
in the art. Examples include absorbents or adsorbents located in
the filter section or tobacco rod of the smoking article.
Particulate filters absorb smoke constituents residing in the
particulate phase of a smoke stream. Adsorbents are often included
and are known to adsorb smoke constituents travelling in the vapour
phase of the smoke stream.
[0003] While such absorbents and adsorbents have removed smoke
constituents from the smoke stream as it passes through the smoking
article, the arrangement of the smoking article has not allowed the
temperature profile of the smoke to be controlled. As such, smoke
constituents are not removed when it is desirable that they be
removed.
Summary
[0004] An embodiment of the present invention provides a smoking
article comprising a filter section comprising a region of
filtration material for removing particulate matter from a smoke
stream, wherein the smoking article is arranged to enhance heat
transfer towards the first region of filtration material.
[0005] In one embodiment a rod of smokable material is provided
wrapped by a wrapper and arranged to form a coal at one end thereof
when lit, wherein the wrapper has heat conducting strips attached
thereto to enhance heat transfer from the coal towards the first
region of filtration material.
[0006] The rod of smokable material may have at least one channel
extending therethrough to enhance heat transfer from the coal
towards the first region of filtration material.
[0007] The at least one channel may comprise a plurality of
channels disposed radially about the circumference of the rod of
smokable material.
[0008] In one embodiment the smoke stream is cooled downstream of
the first region of filtration material for example by means of a
cooling chamber. A region of adsorbent material may be provided in
or downstream of the cooling chamber.
[0009] Perforations for cooling the smoke may be included in a
wrapper circumscribing the filter section.
[0010] A diluent may be provided, for example downstream of the
first region of filtration material.
[0011] The rod of smokable material may comprise a pelletised
composite of tobacco and may further comprise carbon.
[0012] A second region of filtration material may be provided
downstream of the first region of filtration material, wherein the
second region of filtration material has a filtration efficiency
lower than the filtration efficiency of the first region of
filtration material.
[0013] The first region of filtration material may have a retention
value greater than 30 percent or even greater than 70 percent.
[0014] The smoking article may be configured such that the first
region of filtration material only removes matter with boiling
points of or greater than a predetermined level, for example about
250.degree. C., 300.degree. C., 350.degree. C., 400.degree. C.,
450.degree. C. or 500.degree. C.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] So that the present invention may be more fully understood
several embodiments thereof will now be described, by way of
example only, with reference to the accompanying drawings, in
which:
[0016] FIG. 1 is a side cross sectional view of a smoking article
according to one embodiment of the present invention;
[0017] FIG. 2 is a side cross sectional view of a smoking article
according to an alternative embodiment of the present
invention;
[0018] FIG. 3 is a side cross sectional view of a smoking article
according to an alternative embodiment of the present
invention;
[0019] FIG. 4 is a side cross sectional view of a smoking article
according to an alternative embodiment of the present
invention;
[0020] FIG. 5 is a side cross sectional view of a smoking article
according to another embodiment of the present invention; and
[0021] FIG. 6 is a side cross sectional view of a smoking article
according to another embodiment of the present invention;
[0022] FIG. 7 is an end view of a smoking article according to one
embodiment of the present invention;
[0023] FIG. 8 is a plan view of a tobacco rod wrapper according to
an embodiment of the present invention; and
[0024] FIG. 9 is an end view of a smoking article in accordance
with another embodiment of the present invention.
DETAILED DESCRIPTION
[0025] FIG. 1 shows a cylindrical cigarette 10 in accordance with
one embodiment of the present invention. The cigarette 10 comprises
a tobacco rod 15 and a filter section 20. The tobacco rod 15 and
filter section 20 shown in FIG. 1 are attached to each other by
tipping paper 25 although other means for attaching tobacco rods to
filter sections that are known in the art may be employed in the
alternative. The filter section 20 is wrapped in a length of
tipping paper 25 which is longer than the filter section 20 and
connects the tobacco rod 15 to the filter section 20 in a manner
well known in the art.
[0026] The tobacco rod 15 shown in FIG. 1 may be shorter than
conventional tobacco rods that are well known in the art. The
tobacco rod 15 may be formed from reconstituted or pelletised
tobacco circumscribed by a wrapper 26. The wrapper 26 may be formed
from any paper suitable for wrapping tobacco rods that is known in
the art. The wrapper 26 may have a natural permeability between 0
and 25 Coresta units (hereinafter denoted as CU) although
preferably between 2 and 10 CU. A higher permeability may be
achieved using electrostatic perforation.
[0027] The tobacco rod may be 10 to 50 millimetres (hereinafter
denoted as mm) in length, although 30 to 40 mm is a preferred
length. The tobacco rod 15 may be between 14 and 28 mm in
circumference although 17 to 25 mm is a preferred
circumference.
[0028] A binder may be added to the tobacco during manufacture of
the tobacco rod 15 to make the tobacco easier to manipulate and
form into rods. Carbon, in granular form e.g. activated carbon or
any other carbon additive known in the art, may also be added to
the tobacco which, as well as making the tobacco rod 15 easier to
manipulate, facilitating combustion and increasing combustion heat,
is also known to act as an adsorbent of certain smoke
constituents.
[0029] The wrapper 26 which circumscribes the tobacco rod 15 is
made from low permeability paper although wrapping materials other
than paper that are known in the art may be used. The permeability
or porosity of an object is known to affect its burn rate. As such,
the low permeability of the wrapper 26 ensures that the tobacco rod
15 burns more slowly than a tobacco rod wrapped in a higher
permeability wrapper would burn. Where the tobacco rod 15 is
shorter than conventional tobacco rods that are known in the art
the decreased burn rate increases the number of draws or puffs that
a user may take from the cigarette 10 during use.
[0030] The filter section 20 of the cigarette 10 may be wrapped in
a plugwrap 27 in addition to the tipping paper 25. The plugwrap 27
may have a permeability between 0 and 2000 Coresta units.
[0031] The filter section 20 comprises a region of high filtration
efficiency (hereinafter FE) material 30. The region of high FE
material 30 is located at the upstream end of the filter section 20
and is adjacent to the tobacco rod 15. The high FE material 30 may
be heat resistant as it will be exposed to high temperatures and
may be a Cambridge filter pad formed from fibre glass. The high FE
material 30 may also contain materials, such as zeolites, which can
selectively remove individual smoke constituents. The region of
high FE material may be between 1 and 15 mm in length. The
filtration efficiency and/or retention value of the high FE
material should be selected to achieve a high level of particulate
filtration. The retention value according to embodiments of the
invention is greater than 30% and preferably greater than 70% of
particulate matter, although the invention is also effective with
retention values greater than 40%, 50%, 60%, 80% and/or 90%.
[0032] Since the region of high FE material 30 is likely to become
hot during use an insulating layer 31 may be provided between the
high FE material 30 and the tipping paper 25 to reduce the risk of
a user burning himself upon contact with the filter section 20.
[0033] A diluent holding material 35 or aerosol forming agent may
be located within the region of high FE material 30. The diluent
holding material 35 may contain glycerol although other diluents
known in the art may equally be used. The diluent holding material
35 provides another means for modifying the contents of the smoke
by introducing other constituents into and thereby diluting the
smoke aerosol.
[0034] The diluent holding material 35 may alternatively be located
inside a cooling chamber 40 downstream of the region of high FE
material 30. Additional regions of diluent may be located further
downstream the filter section 20. The cooling chamber 40 shown in
FIG. 1 provides a space for smoke to circulate and cool as it
travels downstream. The cooling chamber 40 may be between 10 and 30
mm in length.
[0035] Further downstream from the cooling chamber 40 is a region
of low FE material 45. The low FE material 45 may be formed from
cellulose acetate threads although other filtration materials of
low FE that are known in the art may be used. The low FE material
45 may be formed into a plug which absorbs smoke constituents
passing through. The region of low FE material 45 may be between 10
and 30 mm in length.
[0036] Located within the region of low FE material 45 there may be
adsorbent material 50 which adsorbs smoke constituents. Examples of
suitable adsorbent materials include activated carbon granules,
carbon husks or any other material which is known in the art to
adsorb smoke constituents.
[0037] A mouth end filter section 55 is located at the mouth end 60
of the smoking article 10. The mouth end filter section may be
between 5 and 15 mm in length. The mouth end filter section 55 may
be formed from a plug of low FE filtration material without
adsorbent material located therein. The mouth end filter section 55
prevents the adsorbent material 50 from coming into contact with
the users mouth.
[0038] Although not shown in FIG. 1, flavourants may be included in
the mouth end filter section 55. This can have the effect of
counteracting any change to the taste that may be caused by the
adsorbent material 50.
[0039] The tipping paper 25 is provided with a gap 65 along its
length which allows air to permeate into the filter section 20 and
some smoke constituents to permeate out of the filter section
20.
[0040] An alternative embodiment of the cigarette 10 is shown in
FIG. 2. The filter section 20 is substantially the same as the
filter section 20 shown in FIG. 1. A bore 70 extends along the
longitudinal axis of the tobacco rod 15. The bore 70 provides a
passage for smoke to travel downstream from a burning coal 75
towards the region of high FE filtration material 30. The bore 70
may have a diameter of between 1 and 3 mm. Multiple bores,
substantially parallel to each other, may also be applied. The bore
70 assists in heat transfer towards the filter section 20.
[0041] Forming the tobacco rod 15 from an extruded or compressed
composite of tobacco and carbon, as described above with reference
to FIG. 1, may also make forming the bore 70 easier since the
composite material will aid in the retention of the bore shape and
form. Addition of a binding agent such as guar gum or adhesive
material to cut tobacco can also be used as an aid in retaining
bore shape.
[0042] A cigarette 10 similar to that shown in FIG. 2 but with a
modified filter section 20 is shown in FIG. 3. No gaps, such as the
gaps 65 shown in FIG. 2, are provided in the tipping paper 25. Air
permeates through the tipping paper 25 and plugwrap 27 which are
naturally porous. Similarly, some constituents of the smoke are
able to permeate out of the filter section 20.
[0043] A cigarette 10 similar to that shown in FIG. 1 comprising an
alternative arrangement of the filter section 20 is shown in FIG.
4. In this embodiment, the adsorbent material 50 has been included
in the cooling chamber 40, for instance in granule form filling or
substantially filling the cooling chamber cavity.
[0044] As the cigarette 10 shown in FIG. 1 is lit by a user a coal
75 is formed where the tobacco rod 15 and the wrapper 26
circumscribing the tobacco rod 15 are combusted. A smoke stream is
formed which moves towards the filter section 20 as a pressure
differential is formed as a user draws through the mouth end filter
section 55.
[0045] The smoke stream is formed from various constituents, each
of which exist in a vapour phase and/or a particulate phase. The
amount of each smoke constituent that exists in each phase depends
on the temperature of the smoke. The proportion of a particular
smoke constituent that exists in the vapour phase rises with rising
temperature.
[0046] As the smoke moves downstream through the tobacco rod 15
towards the filter section 20 the temperature of the smoke falls as
it moves further from the coal 75. The fall in temperature of the
smoke is reduced by factors such as changes in the downstream flow
of the smoke. The flow is affected by using short, slim tobacco
rods or via channels or bores of low flow resistance in the tobacco
and the use of low permeability wrappers around the tobacco rod.
Additional factors such as use of thermal conducting materials and
reducing the thermal mass of the tobacco rod are also important
factors.
[0047] As the smoke reaches the region of high FE material 30 a
large proportion of those constituents travelling in the
particulate phase will be removed from the smoke stream. The
constituents in the particulate phase have higher boiling points
than those constituents travelling in the vapour phase. A
relatively small amount of the vapour phase constituents will
inevitably be removed from the smoke stream by the high FE material
30. However, a proportion of these constituents may be eluted from
the high FE filtration material 30 as more smoke is subsequently
drawn through the filter section 20.
[0048] The smoke stream passes through the diluent holding material
35 which dilutes the smoke by adding further constituents to the
smoke aerosol. As stated above, the diluent holding material 35 may
be located either within the region of high FE material 30 or
inside the cooling chamber 40.
[0049] Inside the cooling chamber 40 the smoke cools to a lower
temperature. As the smoke cools various constituents that were
previously in the vapour phase condense into the particulate
phase.
[0050] The rate at which the smoke cools will be affected by
factors such as the positioning of any perforations such as gap 65
in the tipping paper 26 and the level of natural permeability of
the tipping paper 25 and plugwrap 27 as the smoke is ventilated
with ambient air. The gaps 65 may be between 1 and 30 mm in
length.
[0051] It will be apparent to those skilled in the art that the
choice of tipping paper 25 and plugwrap 27 is therefore important
since it allows the cooling of the smoke, and the proportions of
constituents residing in the vapour and particulate phases to be
better controlled.
[0052] As smoke enters the region of low FE material 45 particulate
phase constituents are removed. The amount of particulate material
removed from the smoke stream at the region of low FE material 45
is lower than that removed at the region of high FE material 30 due
to the lower filtration efficiency of the region 45 relative to the
region 30.
[0053] Adsorbent material 50, such as activated carbon or any other
adsorbent of smoke constituents that is known in the art, may be
located within the region of low FE material 45. The adsorbent
material 50 removes smoke constituents mainly in the vapour
phase.
[0054] Finally, the smoke stream is drawn through the mouth end
filter section 55. The mouth end filter section 55 comprises a plug
of low FE material. The mouth end filter section 55 may be
impregnated with flavourants of a type known in the art,
particularly where carbon or other such adsorbents have been
employed upstream.
[0055] FIG. 5 shows an alternative filter arrangement. The filter
section 20 comprises an annular region of high FE material 80
located where the tobacco rod 15 abuts the filter section 20.
Downstream of the annular filter section 80 there is provided a
region of medium FE material 85. The region of high FE material 80
and the region of medium FE material 85 may be wrapped in thermal
conduction material 90, which in turn may be wrapped in insulating
material 95.
[0056] Downstream of this medium FE material 85 there is provided a
filter arrangement substantially similar to the arrangement
described above with reference to FIG. 1. The FE of the region 85
is higher than the FE of the region 45 and lower than the FE of the
region 80.
[0057] Before use, the centre of the annular region 80 forms a
longitudinal bore 86 extending along the length of the annular
region 80 which may be approximately 0.1 to 2 mm in width. During
use, certain smoke constituents build up in the central bore 86,
eventually at least partially blocking the bore 86 to smoke
constituents.
[0058] Therefore, the pressure drop across the filter region 80
during the first few draws, for instance while the filter region 80
has yet to become hot and while the tobacco rod 15 is at its
longest, will differ from that after later draws when the filter
region 80 has become hot and when the tobacco rod 15 has been at
least partially combusted and is therefore shorter. Smoke that
passes through the filter region 80 following the first few draws
will therefore contain different proportions of certain smoke
constituents than will smoke passing through the region 80 from
later draws. This is because some smoke that is drawn through the
region 80 from the earliest draws will travel through the central
bore 86 and will be substantially unfiltered by the region 80.
However, smoke from later draws will be forced through the
filtration material located in the outer annulus of the annular
region 80. Alternative configurations of filter region 80,
differing in shape or composition, that will be apparent to those
skilled in the art may be employed.
[0059] In the cigarette 10 shown in FIG. 5 the region of low FE
filtration material 45 may be wrapped in a plugwrap 96 of high
porosity between the region 45 and the plugwrap 27 which may also
be of similar porosity. The mouth end filter section 55 may be
wrapped in a plugwrap 97 with a porosity lower than that of the
plugwrap 96 which wraps the region of low FE filtration material
45.
[0060] Additional modifications can be made to the various
components within the filter section 20 either in combination or
separately. For example, the plugwrap 27 surrounding the cooling
chamber 40 may be impregnated with an aerosol forming material such
as glycerol or an additional lining layer of a material that can
hold an aerosol forming material can be added.
[0061] FIG. 6 shows a cigarette 10 according to yet another
embodiment. The cigarette 10 is similar to that shown in FIG. 1
however an annular washer 100 is located upstream of the region of
high FE material 30. The washer 100 focuses or channels the smoke
stream to impinge on the region of high FE material 30 and
maintains the velocity of the smoke stream so as to help minimise
heat loss. The region of high FE material 30 and washer 100 may be
wrapped in thermal conduction material 90 which, in turn, may be
wrapped in an insulating material 95.
[0062] The washer 100 may be formed from a conducting material
thereby further enhancing the transfer of heat to the filter
section 20. The cooling chamber 40 may be shaped so to provide a
pressure gradient to assist in aerosol formation. Alternatively,
the cooling chamber 40 may be at least partially filled with an
adsorbent material such as carbon.
[0063] The wrapper 26, shown in FIGS. 1-6 may have additional heat
conducting means extending along its length. FIGS. 7 and 8 show
heat conducting strips 110. The heat conducting strips can conduct
heat from the coal 75 to the region of high FE material 30, 80,
shown in FIGS. 1-6, thus increasing the temperature of smoke at the
point where it leaves the tobacco rod 15 and enters the filter
section 20. The heat conducting strips 110 may be metallic or
comprise any other suitable conductive material.
[0064] As an alternative or in addition to the strips 110 shown in
FIGS. 7 and 8, a liner inside the wrapper 26 or a laminate with the
wrapper 26 may be included, both of which may be in the form of
aluminised paper.
[0065] The heat conducting strips 110 shown in FIGS. 7 and 8 may
alternatively allow heat conducting channels 115 to be formed along
the length of the tobacco rod 15. Smoke may be transferred from the
coal 75 to the filter section 20 with reduced loss of heat along
these channels 115. The strips may be formed from paper,
reconstituted tobacco or any other suitable material that would be
apparent to those skilled in the art. The strips may be applied to
the wrapper 26 before or after the wrapper 26 is wrapped around the
tobacco rod 15. FIG. 8 shows a wrapper 26 with strips 110 applied
thereto prior to being wrapped around a tobacco rod 15. The strips
110 may extend along part of the length of the tobacco rod 15 or
along the entire length of the tobacco rod 15. Channels 115 may
alternatively be formed by placing a corrugated inner wrapping
material 120 between the wrapper 26 and the tobacco rod 15 as shown
in FIG. 9.
[0066] While FIGS. 7 and 9 show end views of cigarettes 10 without
bores 70 present, such bores 70 may be present according to various
embodiments of the present invention.
[0067] Modifications made to alter the temperature profile of smoke
passing through the length of the cigarette 10 and the order of
components within the cigarette 10 can be made without departing
from the scope of the invention which is defined by the appended
claims.
[0068] It should also be understood that while the foregoing
description refers to cigarettes, the scope of the present
invention may apply equally to other smoking articles known in the
art.
Experimental Data
[0069] The smoke profile of a cigarette similar to the cigarette 10
shown in FIG. 1 was analysed. The cigarette differed from the
cigarette 10 shown in FIG. 1 in that the filter section did not
contain diluents, adsorbents or ventilation gaps. Smoke
constituents measured included particulate nicotine, particulate
water, tar (NFDPM), benzo(a)pyrene (B(a)P) and catechol. Also shown
in the table are the ratios of B(a)P to NFDPM and catechol to NFDPM
as well as the number of puffs or draws from each cigarette. The
cigarette according to the invention was compared with two control
cigarettes and the results are set out in the following table. The
cigarettes were investigated by analysing draws of 55 cubic
centimetres (cc) of 2 seconds' duration and with a 30 second
interval between draws.
TABLE-US-00001 TABLE 1 Invention example Control 1 Control 2 Tip
ventilation NO YES NO Total particulate mg/cigarette 19 20 45.8
matter (TPM) Nicotine mg/cigarette 0.7 1.5 2.11 Water mg/cigarette
8.7 3.8 19.2 Nicotine-Free Dry mg/cigarette 9.7 14.7 24.5
Particulate Matter (NFDPM) Puff Number 7.1 9.1 7 Benzo(a)pyrene
ng/cigarette 5.2 14.8 17.7 (B(a)P) B(a)P/NFDPM .times.10.sup.-6
0.54 1.01 0.72 Catechol .mu.g/cigarette 21.2 59.5 74.2
Catechol/NFDPM .times.10.sup.-3 2.19 4.05 3.03
[0070] Exemplary cigarettes according to the invention, together
with Control 1 and Control 2 contained the same blend of tobacco,
tobacco rod and filter length. The cigarette labelled Control 1 had
a conventional cellulose acetate filter with ventilation gaps so
that the total particulate matter (TPM) matched that of the
cigarette of the invention. The cigarette referred to as Control 2
was similar to the invention cigarette however the region of high
FE filtration material 30 was replaced with a low efficiency
cellulose acetate filter. In the invention cigarette the high FE
material was made from glass fibre.
[0071] The results, as displayed in the above table, show that the
ratios of B(a)P and catechol to NFDPM are lower in the example of a
cigarette in accordance with the invention than in either of the
control cigarettes. B(a)P and catechol have relatively high boiling
points and are therefore removed, in their particular phases, by
the high FE filter portion.
[0072] Embodiments of the invention can therefore be arranged to
control the levels of smoke constituents based on their relative
boiling points. For instance, the high FE filter region of
embodiments of the invention can be used to selectively remove only
smoke constituents having relatively high boiling points, for
instance boiling points above a particular temperature, for
instance above temperatures in the region of 250.degree. C.,
300.degree. C., 350.degree. C., 400.degree. C., 450.degree. C. or
500.degree. C. Such constituents would be in the particulate phase
when passing through the high FE filter region 30, 80, 85.
[0073] By cooling the smoke in the cooling chamber 40, the low FE
filter material 45 having the adsorbent material 50, according to
certain embodiments of the invention, can selectively remove smoke
constituents having relatively low boiling points for instance
constituents having boiling points below about 300.degree. C.,
250.degree. C., 200.degree. C., 150.degree. C. or 100.degree.
C.
[0074] In order to address various issues and advance the art, the
entirety of this disclosure shows by way of illustration various
embodiments in which the claimed invention(s) may be practiced and
provide for superior smoking articles. The advantages and features
of the disclosure are of a representative sample of embodiments
only and are not exhaustive and/or exclusive. They are presented
only to assist in understanding and teach the claimed features. It
is to be understood that advantages, embodiments, examples,
functions, features, structures, and/or other aspects of the
disclosure are not to be considered limitations on the disclosure
as defined by the claims or limitations on equivalents to the
claims, and that other embodiments may be utilised and
modifications may be made without departing from the scope and/or
spirit of the disclosure. Various embodiments may suitably
comprise, consist of, or consist essentially of, various
combinations of the disclosed elements, components, features,
parts, steps, means, etc. In addition, the disclosure includes
other inventions not presently claimed, but which may be claimed in
future.
* * * * *