CIGARETTE WITH DECREASED SIDESTREAM SMOKE

CIGARETTE A FUMEE SECONDAIRE REDUITE

English Abstract

Significant decreases in sidestream smoke
production, approximately 30 to 70%, are obtained when
compared to a tobacco filler rod wrapped in a
conventional cigarette paper by double-wrapping the
filler rod, first with a relatively non-porous paper
having a Coresta porosity of about 1 to about 10% and
then with a conventional cigarette paper.

Claims

5
CLAIMS
1. A cigarette comprising a tobacco filler rod wrapped
in an inner wrapping and an outer wrapping,
characterized in that:
(i) the inner wrapping is formed of a relatively
non-porous paper having a Coresta porosity of about
to about 10 units and having a filler content of
about 1 to about 8 wt.%, and
(ii) the outer wrapping is formed of conventional
cigarette paper having a weight of about 35 to
about 65 g/sq.m. and a filler content of about 18
to about 40 wt. %,
whereby a cigarette is provided having a decreased
tendency to produce sidestream smoke when compared to
said tobacco filler rod wrapped only in said
conventional cigarette paper.
2. The cigarette of claim 1 characterized in that said
inner wrapping is formed of relatively non-porous paper
having a Coresta porosity of about 1 to about 5 units.
3. The cigarette of claim 1 characterized in that said
inner wrapping is formed of non-porous paper having a
Coresta porosity of at least about 2 units.
4. The cigarette of claim 1 characterized in that said
outer wrapper contains at least one burn-rate modifying
chemical in an amount of about 0.2 to about 4 wt. %.
5. The cigarette of claim 1, 2, 3 or 4 characterized
in that said inner wrapping contains about 0.1 to about
2 wt. % of at least one burn-rate modifying chemical.
6. A method of assembling a cigarette, which comprises
applying a wrapping to a tobacco filler rod to form a
wrapped filler rod and forming individual cigarettes
from said wrapped filler rod, characterized by:
(a) employing both an inner wrapping and outer
wrapping wherein the inner wrapping is formed of
relatively non-porous paper having a Coresta
porosity of about 1 to about 10 units and having a





filler content of about 1 to about 8 wt. % and the
outer wrapping is formed of conventional cigarette
paper having a weight of about 35 to about 65
g/sq.m. and a filler content of about 18 to about
40 wt. %, and
(b) simultaneously applying said inner wrapping and
said outer wrapping to the tobacco filler rod to
form the wrapped filler rod,
whereby a cigarette is provided having a decreased
tendency to produce sidestream smoke when compared to
said tobacco filler rod wrapped only in conventional
cigarette paper.

Description

Pro~ect "Ghost" 205474~
TITl,E: OF INVENTION
CI~ARF~ WI~ ~E~ RFA~n ~ ~
FIE:LD OF TNVF~NTIO~
The present invention relates to a novel cigarette
structure which enables a decreased sidestream smoke to
be achieved.
BACRGROUND ART
Cigarettes conventionally comprise a paper tube or
wrapper housing a tobacco filler rod and a filter for
removing smoke constituents. One of the common problems
a6sociated with cigarettes is the amount of sidestream
smoke that is formed on static burning, for example,
when the cigarette is idling and not being drawn upon by
the smoker or is simply resting in an ashtray while
burning. Visible sidestream smoke that is formed during
static burning is comprised mainly of particulate matter
and the smoke often is irritating and objectionable to
non-smokers in the vicinity of the idling cigarette.
SUMMARY OF INVF~NTION
In accordance with the present invention, there is
provided a novel cigarette structure which results in a
decreased sidestream emission. In the invention, the
tobacco rod is wrapped with two different paper
wrappers .
There have been a number of prior suggestions to
provide cigarettes with two or more wrappers, including
the following United States patents:
U.S. 3,633,589 Kahane
3, 395, 714 Kahane
3,744,496 McCarty et al
4,231,377 Cline et al
4,505,282 Cogbill et al ,~
4, 585, 016 Grollimund ~,
4,624,268 Baker et al

2 205~745
In one such patent, U. S . Patent No. 3, 633, 589
employs an outer porous conventional cigarette paper and
an inner sheet which is practically impervious to the
passage of air therethrough. Such materials tend to
result in a cigarette which is self-extinguishing. By
employing an inner sheet having a limited porosity, in
accordance with the invention, an improved cigarette i8
achieved, since a significant decrease in sidestream
smoke production is achieved without tending to self-
extinguish.
It will be apparent from the discussion belLow of
the characteristics of the inner wrapper employed herein
that the wrapper material differs from that described in
the prior art . The characteristics def ined herein are
required for the provision of the cigarette with low
sidestream smoke.
U~ ON oF rNVRNTIQN.
~;~u hnl DD IMr~ L ANr~ R~T MOI~l~
2 o The inner wrapper in the present invention is
formed of a particular type of paper which is relatively
non-porous but has some porosity and contains very
little filler. This paper is quite slow burning and
tends to produce a significant decrease in side~tream
smoke. However, on its own, this wrapper tends to
produce an unsightly black ash and has a tendency to
extinguish the cigarette, both of which are undesirable.
It has surprisingly been found that, if the special
paper wrapper is wrapped again with an outer wrapper of
conventional cigarette paper, then the significant
decrease in sidestream smoke is retained, while the
black ash color is not visible and there is a decreased
tendency for the cigarette to go out. In addition, the
cigarette exhibits a decreased tendency to ignite
combustible materials.

Z05~745

The present invention, therefore, employs a double
wrapping of the tobacco rod in the finished cigarette,
namely an inner wrapping of a special paper and an outer
wrapping of a conventional cigarette paper.
The special paper possesses certain properties as
noted above. The paper is relatively non-porous but has
some porosity, possessing a Coresta porosity of about 1
to about 10 units, pref erably about 1 to about 5 units
(Coresta porosity is described in the international
standard I.S.O. 2965). The low but positive porosity is
critical to obtaining a significant decrease in
sidestream smoke, in that papers with a porosi ty of
higher than about 5 Coresta units or lower than about 1
Coresta unit are not nearly as effective. In addition,
below 2, the cigarette becomes self-extinguishing.
The special paper also has a low filler content,
generally about l to about 8 wt.~6, preferably less than
about 5%. The paper may have a paper weight which is
typically about 18 g/sq.m.
In addition to these properties, the inner wrapper
may have other characteristics. One component which may
be present are salts of organic chemicals, such as
citric acid or its salts, to modify the burning rate of
the inner wrapper. Such materials, when present, may
comprise about 0.1 to about 2 wt%.
The inner wrapper may be provided with perforations
to permit the passage of gases through them, with such
perforations being made mechanically, electrostatically
or by laser beam.
The decrease in sidestream smoke which is observed
is a significant decrease, generally approximately 30%
to 70%, over the 6idestream produced by smoking a
conventionally-wrapped cigarette of the same tobacco
blend .
The outer wrapper is provided by conventional
cigarette paper. Such conventional paper preferably has

~ Z0547~5;
a weight of about 35 to about 65 g/sq.m. and a filler
content of about 18 to about 4 0 wt96 . Both rate
~ vt~ ent additives, such as citric acid or its salts,
also may be present in an amount of about 0. 2 to about 4
5 wt~.
The cigarettes according to the present invention
are produced in any convenient manner, generally on a
conventional cigarette making machine, with th~e two
wrappers applied to the tobacco filler rod, se~uentially
10 or preferably simultaneously. The two wrappers may be
laminated together prior to wrapping the tobacco filler
rod, if desired.
l..JUS;J .~ I AT. ~ppLI~'~RTT~TTy
As described above, the present invention provides
a novel cigarette structure having a decreased
sidestream smoke emission by employing a double-wrapping
of the tobacco rod, with an inner wrapper of low
porosity paper. Cigarettes are staple items of c c
20 and, accordingly, the present invention has industrial
application. Modifications are possible within the
scope of this invention.