Note: Descriptions are shown in the official language in which they were submitted.
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Technical Field
Among the reasons why most people smoke conventional cigarettes is that
they wish to inhale an aerosol containing nicotine. However, when smoking such
cigarettes not only is some nicotine lost by pyrolysis and to sidestream during
smoulder between puffs, but, in addition, objectionable compounds such as carbon
monoxide are also inhaled.
The present invention provides a smokeable device in which the above
disadvantages are at least substantially avoided.
Background Art
A previously proposed smokeable device which aimed at avoiding the
above-mentioned disadvantages is described in United States Patent 3,356,094 in
the name of C.D. Ellis et al. This comprised a tube formed of tobacco having a
mouthpiece attached at one end. An axial inner tube of material which is frang-
ible under heat is contained within the tobacco tube and is coated on its inner
surface with an additive material such as nicotine. Thus, on smoking, hot gases
are drawn up the inner tube and release the nicotine in the form of an aerosol
for inhalation by the smoker. However, with this device there is an appreciable
loss of nicotine and other desirable compounds such as flavourants during smoul-
der. There is also a tendency for the inner tube to protrude unattractively from
the burning end during smoking.
Invention
A cigarette-simulating smokeable device for releasing an aerosol into
the mouth of a smoker comprising:
a) a rod of fuel having a longitudinally extending passage therethrough;
b) a chamber in gaseous communication with an end of the passage whereby during
smoking hot gases from the burning fuel rod enter the chamber
c) inhalant material located in the chamber which when contacted by the hot
gases during smoking, forms an aerosol for inhalation by the smoker,
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d) the chamber having at an end remote from the fuel rod a mouth-end closure
member which is permeable to the aerosol.
The chamber and the mouth-end closure member are preferably of unitary
construction and may be formed by moulding or extruding a conventional smoke fil-
ter plug to provide a chamber to contain the inhalant material.
Preferably the fuel rod is a moulding or extrusion of reconstituted
tobacco and/or tobacco substitute.
The wall of the fuel rod is preferably impermeable to air.
The inhalant material may comprise nicotine source material or spray
dried granules of flavourant whose composition lies within the range 30-60% by
weight of a solution of flavourant in triacetin or benzyl benzoate encapsulated
in 40-70% by weight of gum acacia or a modified starch. The inhalant material
may further comprise microcapsules formed by the coacervation method which cap-
sules comprise 50-80% by weight of flavourant in a mixture of gelatin and gum
acacia.
Preferably the end of the fuel rod to be lighted is closed by a com-
bustible member.
Drawings
The invention will now be described by way of example with reference
to the accompanying diagrammatic drawings in which:-
Figure 1 J Figure 2 and Figure 3 are longitudinal sections throughfirst, second and third embodiments of a smokeable device; and
Figure 4 shows a section through a chamber for containing inhalant ma-
terial.
The smokeable device shown in Figure 1 comprises a generally cylindri-
cal fuel rod 11 extruded or moulded from tobacco or a tobacco substitute. An
example of such a tobacco substitute is that described in our United Kingdom
Patent No. 1J113J979. An axial passage 12 extends the length of the fuel rod
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ll. The wall of the rod 11 is substantially impervious to air so that when an
end is lighted the flow of moist hot gases produced during combustion is con-
fined to pass down passage 12 towards aerosol precursor chamber 14 during smok-
ing. A conventional cellulose paper filter tip 13 is provided at an end of the
device remote from the fuel rod. The filter is preferably as short as practica-
ble as its purpose is merely to close the end of chamber 14.
Chamber 14 comprises a cylindrical body 15 which is formed of an air
impermeable cellulosic material such as cellulose acetate or paper. The aerosol
precursor (or inhalant) material contained in the chamber 14 comprises a vola-
tile flavourant solution micro-encapsulated in gum acacia heat rupturable gran-
ules of 16-52 mesh size.
In use, when the end 10 of the fuel rod is lighted, air is drawn
axially through the device when a smoker takes a puff. Air entering the passage
12 passes the burning coal and is heated and mixed with the combustion gases
from the burning rod. This stream of hot gases passes down the passage 12 and
between the granules of the precursor material to exit through the filter tip 13
into the mouth of the smoker. The flow of hot gases through the precursor mate-
rial ruptures the microcapsules and releases the volatile solution to form an
aerosol of flavourant. Thus the smoker inhales an aerosol of flavourant sub-
stantially free from toxic compounds with each puff on the device.
The overall length of the device is 70 mm, the diameter is 7 mm andthe diameter of the passage 12 is 2.2 mm.
The embodiment shown in Figure 2 is generally similar to that shown in
Figure 1 but differs in the design of the aerosol precursor chamber 14. In this
embodiment the chamber 14 and the filter tip 13 are formed as an integral unit
in the following manner. A conventional cellulose acetate filter tip has a cham-
ber 14 moulded in one end by the insertion of a hot forming probe. Inhalant ma-
terial in the form of a spray dried powder is then injected into the chamber 14.
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As this material is insufficiently adhesive to be retained in the chamber, an
air porous disc 16 is provided between the chamber and the fuel rod 11. A com-
bustible plug 17 located in the open end 10 of the fuel rod to close the passage
12 assists even lighting of the rod and helps to make the device resemble a con-
ventional cigarette. The plug 17 is formed of the same material as the fuel
rod. Plug 17 may also have the form of a disc having the same area as the cross-
section of the fuel rod 11.
In use, with smokeable devices of either embodiment, the temperature
of the burning coal is in the region of 800C and the temperature of the air mix-
ture downstream at the inhalant material varies between 130C and 500C during
the smoking of the device.
Figure 3 shows a further embodiment of smoking device which again dif-
fers in the design of the aerosol chamber 14. The chamber 14 comprises a cylin-
der l9 moulded from cellulose acetate which is closed at the mouthpiece end by a
cellulose-paper filter 13. Adjacent the end of the fuel rod 11 the chamber 14
contains an annular cartridge 20 formed of flavourant-containing spray-dried gum
acacia microcapsules. The annular cartridge 20 defines a tubular passage 21
which connects with the axial passage 12 in the fuel rod ll. The remaining por-
tion of the chamber 14 forms an aerosol mixing chamber 22. In use hot, moist
gases are drawn down passage 12 and into passage 21 where they pass over the
microcapsules causing them to rupture and release their flavourant. The flavour-
ant-containing gases pass into the mixing chamber 22 where they expand and inter-
mix thus ensuring an evenly distributed aerosol.
Figure 4 shows a section through a further embodiment of precursor
chamber 14. Cellulosic material 18 is extruded in lengths having the section
shown. During the extrusion a length of flavourant-containing material is simul-
taneously extruded axially through the length of the outer extrusion. The re-
sulting extrusion is then cut into short lengths each of which forms an integral
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aerosol precursor chamber. Alternative sections to that shown in Figure 3 may
be used. It is also envisaged that the flavourant containing material may be
added independently to pre-prepared chambers 14.
In order to access the performance of smokeable devices as described
above experiments were carried out to determine the yield of a flavourant into
the mainstream aerosol during smoking. Triacetin and hexadecane were selected
in place of nicotine as these behave in a similar fashion to nicotine but are
easier to detect experimentally. The tests used the normal smoking regime of
1 puff of 2 seconds duration and 35 ml volume every minute.
A test carried out with the embodiment of Figure 1 used triacetin
spray-dried in gum acacia. The particles were sieved and only those of 16-52
mesh size were used. The triacetin transfer into the mainstream aerosol was be-
tween 0.57 and 1.17 mg. Where the test was carried out using nicotine in place
of triacetin the yield was 0.77 mg.
A test was carried out using the embodiment of Figure 2 and the same
flavourant-containing material as in the previous test. With this embodiment
the triacetin transfer was between 0.9 and 1.85 mg.
Finally the embodiment of Figure 3 was tested. In this embodiment
hexadecane was used to simulate the flavourant. The yield into the mainstream
aerosol was 0.83 mg.
The fuel rod 11 may in either embodiment have a conventional cigarette
paper wrapped around it. The rod may further be formed of a mixture of tobacco
substitute material and carbon or alternatively formed of other suitable combus-
tible material, e.g. wood pulp, straw and heat-treated cellulose or an SCMC and
carbon mixture.
It is envisaged that the aerosol chamber 14 of Figure 3 could be pre-
pared from a rectangular piece of cellulose acetate having a band of flavourant-
containing material applied along one of its edges. The rectangular piece would
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be rolled to form a tube and the abutting edges would then be joined. As a re-
sult of the rolling, the band of flavourant-containing material would adopt the
annular form 20 of Figure 3.
The aerosol material may, as an alternative to a flavourant solution,
comprise a solution of a flavourant and/or nicotine in triacetin or benzyl
benzoate. Any psycho-active or physiologically active compound such as ephed-
rine or a nicotine/ephedrine mixture may be used as may emollients, smoothing
agents or amerliorants.
The inhalant material may comprise nicotine encapsulated in a spray
dried powder. Alternatively the nicotine may be encapsulated in an expanded ma-
trix of a thermoplastic material, eg. polyurethane.
The inhalant, or flavour-containing material may comprise nicotine
source material or spray dried granules of flavourant whose composition lies
within the range 10-100%, but preferably 30-60% by weight of a solution of fla-
vourant in triacetin or benzyl-benzoate encapsulated in 10-70%, but preferably
40-70% by weight of gum acacia or a modified starch. The inhalant material may
further comprise microcapsules formed by the coacervation method which capsules
comprise 10-90%, but preferably 50-80% by weight of flavourant in gum acacia,
gelatin, or a mixture thereof.
As an alternative to gum acacia the flavourant-containing material
could comprise gelatin.
The fuel rod may be impregnated with burn-modifying material, e.g.
potassium citrate. The fuel rod may also be impregnated with fragrances which
are released on smoking.
In the case where the inhalant material comprises a spray dried powder
the need for the provision of an air porous disc 16 may be obviated if after in-jecting the powder into the chamber 14, the filter tip is left to stand in con-
ditions of high humidity. This method results in the powder becoming adhered to
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the inner surfaces of the chamber 14.
Thus the smoking devices described in accordance with the invention
provide a means of controlling the substances which are released into the main-
stream smoke. The loss of the inhalant material by pyrolysis and to sidestream
s during smoulder is also minimised. Additionally such smoking devices closely
resemble normal cigarettes in appearance.
