Note: Descriptions are shown in the official language in which they were submitted.
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FILTER CIGARETTE AND METHOD OF MAKING FILTER
CIGARETTE OF AN ELECTRICAL SMOKING SYSTEM
BACKGROUND
s In cigarettes of the type used in electrical smoking systems such as
are disclosed in commonly owned US 5 388 594; US 5 692 525;
US 6 209 547; US 6 289 898; US 6 615 840 and US 6 888 313, and in U.S.
Application Publication No. 20030131859, which patents and application
publications are incorporated by reference in their entirety, it is
generally desirable to duplicate aspects of the experience of smoking
a regular cigarette, such as resistance to draw. However, the manner
in which smoke is generated and air is drawn through the cigarette for
the electrical smoking system is quite different from the way smoke is
generated and air is drawn through a regular cigarette because of the
vastly different physical structure of the smoking system versus the
regular cigarette. It is desirable to provide cigarettes for use in
electrical smoking systems having features that facilitate simulating
the experience of smoking a regular cigarette.
SUMMARY
According to one embodiment, a cigarette for an electrical
smoking system includes a filter tipping including a web including
added filtering material and a tubular wrapper around the web, and a
tobacco rod portion adapted to generate a puff of smoke upon being
heated by at least one heating element during smoking, the tobacco rod
portion being attached to the filter tipping.
According to another embodiment, a method for making a cigarette
for an electrical smoking system includes making a filter tipping by
surrounding a web including added filtering material with a tubular
wrapper, and attaching a tobacco rod portion adapted to generate a
puff of smoke upon being heated by at least one heating element during
smoking to the filter tipping.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. lA-1C are cross-sectional side views of cigarettes
according to various embodiments.
FIGS. 2A-2C show end views of a cigarette filter according to
various embodiments.
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FIG. 3 shows a web having a three-dimensional shape being
compressed and surrounded by a wrapper according to an embodiment.
FIG. 4 shows a cigarette filter that uses multiple webs according
to an embodiment.
DETAILED DESCRIPTION
Cigarettes 2la-21c according to embodiments are shown in FIGS.
1A-1C. The cigarettes all include a cigarette filter 23 including a
web 25 including filtering material and a tubular wrapper 27 around
the web. The cigarette 21 includes a cylindrical member, e.g., a
tobacco containing rod portion 37a-37c, for generating smoke attached
to the cigarette filter. The cigarette 21 is of the type usable in an
electrical smoking system such as is disclosed in commonly owned
US 5 388 594; US 5 692 525; US 6 209 547; US 6 289 898; US 6 615 840
and US 6 888 313, and in U.S. Application Publication No. 20030131859,
which patents and application publications 'are incorporated by
reference in their entirety.
The cigarette filter 23 can replace or be used together with a
free flow filter. Several possible, non-limiting arrangements of
components are shown in FIGS. lA-1C. FIG. 1A shows a cigarette 21a
wherein a filter 23 isdisposed in a filter tipping 33a including the
filter 23 positioned adjacent a filter plug 35, which can be, for
example, a conventional cellulose acetate tow filter. A tobacco rod
portion 37a is attached to the tipping 33a and includes a free flow
filter 39, a void 41 or open space, and a tobacco plug 43 wrapped in a
wrapper 45 that may include a tobacco web, although other arrangements
can also be used. In the electrical smoking system, heat is applied
to the wrapper 45 to heat tobacco (e.g., the tobacco web and the
tobacco plug 43) during puffing of the cigarette to thereby generate
smoke. In addition tb removing targeted constituents from smoke,
using the filter 23 instead of or in addition to conventional tubular
free-flow filters can facilitate' adjustment of features of the
cigarette such as resistance to draw (RTD) which can be useful in
simulating the experience of smoking a traditional, lit-end cigarette.
FIG. lE shows a cigarette 21b with a tipping 33b and tobacco rod
portion 37b wherein the free flow filter 39 from the cigarette 21a is
eliminated. FIG. 1C shows a cigarette 21c with a tobacco rod portion
37c wherein the filter 23 is used together with a free flow filter 47
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in the tipping 33c between the filter 23 and the filter plug 35. The
foregoing are only several illustrative ones of numerous possible
variations. There may be voids, free flow filters, filter plugs,
tobacco plugs, and any other desired structures in the cigarette.
In the cigarette filter 23, the web 25 may include paper. The
web 25 may include a coated paper, an impregnated paper, carbon paper,
a laminate, or a laminate including paper. The web 25 may be formed
into a non-planar shape, such as by folding or rolling or bending the
web. As seen in FIG. 2A, the web 25 may be formed into an accordian
shape. As seen in FIG. 2B, an accordian-shaped web 25 may be formed
into a circular shape. As seen in FIG. 2C, the web 25 may be crimped
and formed into any one of numerous possible shapes. As seen in
FIG. 3, the web 25 may be formed into any desired three-dimensional
shape by a suitable forming apparatus 101 and then swaged or otherwise
is processed by a suitable compressing apparatus 103 to compress the
shape. The web 25 may exert a force on the wrapper 27 to assist in
maintaining a three-dimensional shape for the filter 23. The wrapper
27 may be made from a web but may be formed from any structure suited
for providing an outer covering for the web 25, such as a pre-formed
tube.
The filtering material is any suitable material, such as a
material that reacts with at least one constituent of cigarette smoke.
The filtering material can include an aminopropylsilyl group
covalently bonded to a non-volatile inorganic substrate. See, for
example, commonly-owned US 6 209 547, US 6 584 979, and US 6 595 218,
which are hereby incorporated by reference. The aminopropylsilyl
group is preferably a 3-aminopropylsilyl group. The substrate is
preferably silica gel or molecular sieve material. The material may
be provided on a web 25 of paper or other suitabl'e material.
In accordance with an embodiment, the physical and chemical
properties of the filler material used to produce webs 25 of paper for
making filters 23 are chosen and utilized to reduce the aldehyde
content of the smoke produced during combustion/pyrolysis of the
smoking article. The paper filler includes an ammonium-containing
compound, which when heated evolves ammonia, which may chemically
react with aldehydes in tobacco smoke and/or modify the
combustion/pyrolysis reactions thereby reducing the initial formation
of aldehydes, thereby decreasing the delivery of such aldehydes to a
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smoker. The filtering material can be an ammonium containing compound
filler used in the web. See, for example, commonly-owned US 6 289 898
and US 6 615 840, which are incorporated by reference.
A suitable ammonium-containing compound is an inorganic ammonium
metal salt, such as an ammonium-alkaline earth metal salt, such as
MgNH4 P04=xH2O, wherein x ranges from 1 to 6(AMP). It is preferred
that the ammonium-containing compound have a low solubility in water
so as to be compatible with conventional papermaking processes, e.g.,
the filler is substantially insoluble in an aqueous dispersion
containing ingredients of the paper, such as flax, etc. That is, the
ammonium-containing compound should be stable enough in a papermaking
process to survive intact as filler in the final paper product. This
includes sufficient thermal stability to survive the drying steps in
the papermaking process. Magnesium ammonium phosphate and its
is hydrates are well-suited to conventional papermaking processes, and
evolve ammonia during the smoking process in a manner that greatly
decreases the content of certain low molecular weight aldehydes in
smoke. Magnesium potassium phosphate is isostructural with magnesium
ammonium phosphate and can form solid solutions therewith effective
for reducing the aldehyde content in smoke. An ammonium magnesium
phosphate filler that consists essentially of the monohydrate form of
magnesium ammonium phosphate is especially preferred.
The ammonium-containing compound filler can also comprise one or
more of the following mineral phases: dittmarite, struvite, hannayite,
schertelite, mundrabillaite and swaknoite.
Ammonium-containing compounds considered useful as filler
materials have a range of surface areas, a range of particle sizes
(mostly in the micron range), possess appropriate opacity, have low
solubility in water (required for papermaking), and possess other
properties that are considered desirable in fillers for papers used in
cigarettes. In similar papers used for cigarette papers,the filler
preferably has a particle size below 25 m, more preferably below 10Am.
The filtering material can include nanoparticles. Some or all of
the nanoparticles can be a. filler used in= the web and some or all of
the nanoparticles can be disposed on a surface of the web. The
nanoparticles can be capable of acting as at least one of an oxidant
for converting carbon monoxide to carbon dioxide and a catalyst for
converting carbon monoxide to carbon dioxide, or both. The
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nanoparticles can be selected from the group consisting of metals,
metal compounds, metal oxides, doped metal oxides, and mixtures
thereof. Suitable nanoparticles are preferably selected from the
group consisting of Fe203, CuO, Ti02, Ce02i Ce203, A1203, Y203 doped with
5 zirconium, Mn203 doped with palladium, and mixtures thereof. See, for
example, commonly-owned US 6 769 437 and U.S. Published Patent
Application Nos. 20030075193 and 20030131859.
The nanoparticles preferably have an average particle size less
than about 500nm, preferably an average particle size less than about
io 100nm, more preferably an average particle size less than about 50nm,
and still more preferably an average particle size less than about
5nm. The nanoparticles preferably have a surface area of at least
about 20m2/g, and more preferably a surface area of at least about
200m2/g.
is Though embodiments have been described in conjunction with a
single web 25, it will be appreciated that multiple webs 25 may be
used, as seen in FIG. 4. Also, more than one type of filtering
material may be used on a single web or on different webs. In other
embodiments (not shown) the filter may be disposed in the tobacco rod
20 portion or in the tobacco rod portion and the tipping. Where multiple
webs are used, they may occupy substantially the same volume, such as
where they are layered next to one another, or may be arranged at
different axial locations along the length of the cigarette that may
be next to one another or not, as desired or necessary.
25 While this invention has been illustrated and described in
accordance with a preferred embodiment, it is recognized that
variations and changes may be made therein without departing from the
invention as set forth in the claims.
