Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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SPECIFICATION FOR FOREIGN APPLICATIONS
APPLYING LIQUID ADDITIVF. FOAM TO TOBACCO FILLER
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The present invention relates to an apparatus and method for
processing tobacco and more particularly to the application of a
liquid addi~ive foam to tobacco in the course of cigarette
manufacturing.
Our European Patent Application No. 85305139.9, published on
26th February 1986 under number 0172654 describes a ~ethod iD which
a ~i~uid additive foam is applied to tobacco in the course o.f
manufacture of cigarettes, either in the chimney of a cigarette-
~aking machine - particularly the belt guide section of the
chimney - or as the tobacco is deposited on the moving garniture
tape, or between the ecreteur and the short tongue, or at the short
tongue. It also disclosed that the liquid additive foam could be
injected into the tobacco rod of a finished cigarette by injecting
it through the end of the tobacco rod using a needle.
Because the ~dditive material was applied as a foa~, a small
amount could be more uniformly applied over a large amount of
tobacco. Further, much less liquid or solvent need be used as
compared to earlier methods of applying additive material.
- However, even the small amount of liquid used in the liquid
additive foam may mar the wrapper of a inished cigarette made with
the treated tobacco filler. Further3 where the liquid additive
foam is a binder, intended to increase the firmness of the finished
cigarette, if the filler ls compressed to make the cigarette before
the foam has set, the full firmness-increasing effect of the binder
may not be realized.
It would be desirable to be able to dry and set a liquid
additive foam that has been added to tobacco flller in a cigarette
making machine, said drylng and setting occurring prior to the
incorporatlon of the filler into a finished cigarette.
` Summary of the Invention
It is therefore an ob~ect of this inventlon to be able to dry
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and set 8 liquid additive foam that has been added to tobacco flller
ln a cigarette making machine, said drylng and settlng occurrlng
prior to the lncorporation of the filler lnto a finished clgarette.
In accordance with this lnventlon, there ls provided apparatus
for manufacturlng cigarettes comprislng a cigarette maker having
means for providing a moving stream of tobacco, an inlet chimney for
receiving cut tobacco filler, an ecreteur section, and a garnlture,
movable garniture tape and short tongue for forming said filler lnto
a cigarette rod. The apparatus also comprises means for producing
8 liquid additive foam, means for applying said liquid additive foam
to said moving stream of tobacco, and means for drying and setting
said applied liquid additive foam.
A cigarette manufacturing method according to this invention
comprises providing a moving stream of tobacco, producing a liquid
additive foam, applying said liquid additive foam to said moving
stream of tobacco, and drying and setting said applied liquid
additive foam.
The present inventlon involves treating tobacco filler with a
flavouring or other material applied in the form of a liquid
additive foam. By using a liquid additive foam, the filler can be
impregnated thoroughly due to the exceptional penetrating sbility of
foam. The low density of foam also enables ~pplication of
materials in a ~uantity sufficient to permeate the filler without
staining the cigarette wrapper. The liquid additive foam may be
added to the filler either in the chimney of a cigarette maker,
before the tobacco leaves the vacuum belt, as the tobacco drops off
the vacuum belt, at the short tongue, or at any other suitable
location prior to enclosing the tobacco rod in a wrapper. Uhere
the liquid additive foam is applied before thP short tongue, the
treated filler can be dried and set by the application of hot air,
smbient temperature air, reduced humidity ambient temperature air,
or microwave radiation. The liquid additive foam may also be
applied to the tobacco filler prior to transporting the filler to a
cigarette maker or it may be applied to finished cigarettes through
a hollow tube.
The above and other objects and advantages of the invention
will be apparent upon consideratlon of the following detailed
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descrlption, tsken in con~unctlon wi~h the accompanying drawlngs~ in
which like r ference characters refer to like parts throughout, and
in which:
Figure 1 is a vertical cross-sectlonal view of the chimney
section of a cigarette maklng machlne, modlfied for drying and
setting applied liquid additive foam;
Fi%ure ? is a vertical cross-sectional view of the chimney
section of a cigarette-making machine, modified ln a second way for
drylng and setting applied liquid additive foam;
Figure 3 i6 a vertical cross-sectional view of the chimney
section of a cigarette-making machine, modified in a thlrd way for
drying and setting applied liquid additive foam;
Figure 4 i8 a vertical cross-sectional view of the ecreteur
section of a cigarette-making machine, modified for drying and
setting applied liquid additive foam.
Figure 5 shows a modification of Figure 4.
After the foamed materlal has been added to the tobacco filler
as described in our European patent specification No. 0172654,
referred to above, it is preferable to dry and set the foam,
evaporating the liquid or solvent contained in it. As discussed
above, drying reduces the cigarette wrapper staining that can be
caused even by the small amount of liquid or solvent in the foam.
In addition, if a particular final moisture level is desired,
~drying allows the addition of more sdditive while achieving the same
final moisture level. Setting the foam optimizes its firmness-
improving abilities.
The embodiments shown in Figures 1 and 2 use conditioned forced
air to dry and set the foamed material. The conditioned air is
heated to a temperature appropriate to dry and set the particular
foamed material being used and is humidified to prevent overdrying
or toasting of the tobacco filler. Alternatively, the
conditioned air can be ambient temperature air at ambient or reduced
humidity.
In the embodiment of Figure 1, the drying and setting take~
place in the chlmney 10 of a cigarette maker such as is shown in
Figure 1 of Ewropean patent specification 0172654.
Tobacco ls blown from the chimney 10 onto a perforated vacuum
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belt l2 drlven by roller6 14 and 16 to convey the tobacco to
ecreteur or trlmmer knife a6sembly 18. Fosm generator 50 supplle6
addltional foamed adhe61ve through pipe 51 to a nozzle 58 which
in~ect6 adhesive parallel to the belt 12.
The cigarette making machine normally includes a fan 120 which
supplies air through conduit 121 to chimney 10 to transport the
tobacco filler. The air is removed by manifold 122 and returned
to fan 120 by conduit 123. By interposing conditioner 124 in
conduit 123, the air stream in chimney 10 can be heated and
humidified to the proper levels, or otherwise conditioned, and then
8 portion of the conditioned air can be allowed to impinge on the
tobacco filler held by vacuum belt 12 downstream of foam-applying
nozzle 58. The air flow in chimney 10 is illustrated by arrows A.
In the embodiment shown in Figure 2, vacuum belt 12' extends
beyond ecreteur 18, running over rollers 14', 16, and garniture tape
22 ~shown in European patent specification 0 172 654) does not begin
until the end of vacuum belt 12'. A supply 130 of air,
conditioned as described above, provides a flow of air for drying
and setting the foamed material between ecreteur 18 and garniture
tape 22. Air supply 130 can come from fan 120 or could be a
fieparate 6upply.
The embodiments of Figures 1 and 2, which rely on heated or
conditioned air to perform the drying and setting of the foamed
material, may result in proper drying and setting of the outer
layers of the mass of tobacco filler exposed to the air, but, even
with conditioning of the relative humidity level of the air, may
result in overdrying or toasting of those outer layers if the
process is continued until the interior of the mass is also dried
and set. This results, in particular, from the tendency of the
foamed material, while wet, to accumulate at the crossover points
between tobacco shred6 in the interior of the mass of tobacco
filler. Therefore, in the embodiments of Figures 3 and 4, the
foamed material added to the tobacco filler i8 dried and set by
e~sposing it to microwave radiation, which reaches and heats moisture
in foamed material within the tobacco mass at essentially the same
time that it reaches and heats the moisture in ioamed material in
the outer layers of the tobacco mas6.
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As ln Flgure 2, vacuum belt 12' ex~ends in the embodiment of
Figure 3 beyond ecreteur 18, runnlng over rollers 14', 16, and
garniture tape 22 (not shown) does not begln until the end of vacuum
belt 12'. The section of vacuum belt 12' between ecreteur 18 and
garnlture tape 22 passes through a microwave cavity 140, so that the
tobacco filler containing the wet foamed material is exposed to
microwave radiation as it passes through cavity 140, drying and
setting the foamed material. The power level of the micr~wave
radiation i6 set based on the speed of vacuum belt 12' and the total
amount of energy required to adequately dry and set the foamed
material. For example, if 480 watt-seconds of energy are
required, and belt 12' moves at 400 feet per mlnute, then if
microwave cavlty 140 has a length of 0.4 feet, so that tobacco
transits cavity 140 in 0.06 seconds, the power level should be set
to 8000 watts.
In the embodiment of Figure 4 another method of adding foamed
material to the tobacco is used. A splitter blade 63 turns in the
direction shown at such a speed that the linear velocity of the
outer edge of the blade 63 is greater than or equal to the speed of
advance of the tobacco in the belt 12. The blade 63 opens up the
moving stream of tobacco for foamed ma~erial to be applied inside
the tobacco bed from generator 50 through nozzle 58.
A garniture tape 22 running over an idler roller 24d carries
the tobacco under a short tongue 30 which comprises a compression
foot 32 mounted on an arm 34. The compression foot has a
longitudinal channel of semi-cylindrical shape which cooperates with
a garniture (not shown) to form the tDbacco into a cylindrical rod~
Cigarette paper 26 ifi fed onto the garniture tape 22 to be wrapped
round the formed rod. The microwave cavity 40 is positioned round
the garniture tape 22 after the end of vacuum belt 12 and before
short tongue 30.
The power level and length of microwave cavity 140 are
determined in this case based on the speed of garniture tape 22,
rather than that of the vacuum belt.
Figure 5 shows a modification of the embodiment of Figure 4 in
which the tobacco passes through the microwave cavity 140 before
being delivered to the garniture tape 22. This may be of ad,vantage
3fl~:)
lf the short perlod durlng which the moist tobacco rests on the
cigarette paper 26 in the apparatus of Flgure 4 results in
sLaining. It also avoids passage of the cigarette paper through
the microwave cavity. The tobacco falling from the vacuum belt 12
i6 received by a belt 160 running around rollers 161 and 162 and is
advanced through the cavity 140 on the belt 160. It is delivered
to the garniture tape 22 downstream of the cavity 140.
Because it i8 deslrable that the microwave energy be used ~o
dry and set the foamed material as efficiently a5 possible, and to
prevent damage to microwave cavit~ 140, the embodlments of Figures
3, 4 and 5 should be constructed 130 that only microwave-compatible
materials pass through microwave cavlty 140. By microwave-
compatible is meant microwave transparent, i.e., nelther microwzve-
absorptive nor microwave-reflective. The use of microwave-
absorptive materials would waste energy because energy that would
otherwise be used to dry and set the foamed material would be
absorbed by other materials in the cavity. The use of microwave-
reflective ~aterials, particularly metals, would cause internal
reflections of microwave energy within cavity 140 which could damage
the cavity.
In particul~r, in the Pmbodiment of Figure 3 vacuum bel~ 12
should be nonmetallic. In addition, at least that portion of belt
guide 62 (not shown in Figure 3) which passes through cavity 140
should also be nonmetallic. In the embodiment of Figure 4,
- garniture tape 22, and at least that portlon of garniture ~0 (not
shown in Figure 4) passing through cavity 140, should be
nonmetallic. In the embodiment of Figure 5, belt 160 should be non-
metallic. In any of these three embodiments, the nonmetallic
material used is preferably microwave-transparent ~nonabsorptive) as
well.
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