U.S. patent application number 12/340322 was filed with the patent office on 2009-06-25 for smoking article with improved extinguishing characteristcs.
This patent application is currently assigned to REEMTSMA CIGARETTENFABRIKEN GMBH. Invention is credited to Thomas Pienemann.
Application Number | 20090159090 12/340322 |
Document ID | / |
Family ID | 39422005 |
Filed Date | 2009-06-25 |
United States Patent
Application |
20090159090 |
Kind Code |
A1 |
Pienemann; Thomas |
June 25, 2009 |
SMOKING ARTICLE WITH IMPROVED EXTINGUISHING CHARACTERISTCS
Abstract
A smoking article includes a tobacco rod and a wrapper, wherein
the wrapper includes at least one zone treated with an inorganic
salt providing reduced ignition propensity. Preferably, the
porosity of the wrapper in the treated zones is larger than 10 CU.
Suitable inorganic salts are, e.g., magnesium chloride, aluminum
sulfate, alum, sodium tetraborate, the hydrated forms of these
compounds, sodium chloride, or mixtures thereof.
Inventors: |
Pienemann; Thomas;
(Rosengarten, DE) |
Correspondence
Address: |
HOVEY WILLIAMS LLP
10801 Mastin Blvd., Suite 1000
Overland Park
KS
66210
US
|
Assignee: |
REEMTSMA CIGARETTENFABRIKEN
GMBH
Hamburg
DE
|
Family ID: |
39422005 |
Appl. No.: |
12/340322 |
Filed: |
December 19, 2008 |
Current U.S.
Class: |
131/284 ;
131/365 |
Current CPC
Class: |
A24C 5/005 20130101;
A24D 1/022 20130101; D21H 19/64 20130101; D21H 17/66 20130101; A24D
1/025 20130101; A24D 1/02 20130101; D21H 23/22 20130101 |
Class at
Publication: |
131/284 ;
131/365 |
International
Class: |
A24C 1/00 20060101
A24C001/00; A24D 1/02 20060101 A24D001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 20, 2007 |
EP |
07400034.0 |
Claims
1. A smoking article comprising: a tobacco rod; and a wrapper, said
wrapper including at least one zone treated with an inorganic salt
providing reduced ignition propensity.
2. The smoking article as claimed in claim 1, said treated zone
having a porosity greater than 10 Coresta units.
3. The smoking article as claimed in claim 1, said inorganic salt
comprising at least one substance selected from the group
consisting of magnesium chloride, aluminum sulfate, alum, sodium
tetraborate, hydrated magnesium chloride, hydrated aluminum
sulfate, hydrated alum, hydrated sodium tetraborate, and sodium
chloride.
4. The smoking article as claimed in claim 1, said inorganic salt
in the treated zone of the wrapper being present in an amount
having a range of from 0.2 mg/cm.sup.2 to 20 mg/cm.sup.2.
5. The smoking article as claimed in claim 1, said wrapper
including a plurality of discrete zones treated with the inorganic
salt, said discrete zones presenting a total treated area that is
smaller than the total surface area of the wrapper.
6. The smoking article as claimed in claim 5, said discrete zones
being arranged as bands extending along the circumference of the
smoking article, each band having a width, measured along an axis
of the tobacco rod, of from 2 mm to 12 mm.
7. The smoking article as claimed in claim 6, said wrapper
including at least two discrete zones, adjacent ones of said zones
being separated by at least 1 mm.
8. The smoking article as claimed in claim 1, said smoking article
further comprising a filter.
9. The smoking article as claimed in claim 1, wherein the smoking
article is a cigarette, said wrapper being a cigarette paper.
10. A method of manufacturing a smoking article as defined in claim
1, said method comprising the steps of: applying the inorganic salt
to the wrapper by a solution or a suspension.
11. The manufacturing method as claimed in claim 10, said solution
being heated to improve the solubility of the inorganic salt.
12. The manufacturing method as claimed in claim 10, said solution
solvent or suspension agent comprising water.
13. The manufacturing method as claimed in claim 10, said applying
step including applying the inorganic salt to the wrapper by a
technique selected from the group consisting of gravure printing,
inkjet printing, spraying, and sizing.
14. The manufacturing method as claimed in claim 10, said applying
step including applying the inorganic salt to the wrapper by sizing
in a papermaking process for providing the material of the
wrapper.
15. The manufacturing method as claimed in claim 10, further
comprising the steps of: providing the material of the wrapper by a
papermaking process; and cutting a mother reel into bobbins
containing wrapper material, said applying step being performed
immediately after said providing step and simultaneously with said
cutting step.
16. The manufacturing method as claimed in claim 10, said applying
step including applying the inorganic salt to the wrapper during an
offline rewinding step of a bobbin containing wrapper material.
17. The manufacturing method as claimed in claim 10, said applying
step including applying the inorganic salt to the wrapper online in
a cigarette making process; and wrapping a continuous tobacco rod
with the wrapper material, said applying step being performed
before said wrapping step.
18. The manufacturing method as claimed in claim 10, said applying
step including applying the inorganic salt to the wrapper online in
a cigarette making process; and wrapping a continuous tobacco rod
with the wrapper material, said applying step being performed after
said wrapping step.
19. A paper forming a wrapper for rolling a cigarette that includes
a tobacco rod, wherein the wrapper is configured to radially
surround the rod, said paper comprising: at least one zone treated
with an inorganic salt providing reduced ignition propensity.
20. The paper as claimed in claim 19, said paper being formed as a
tube, said tube including a filter.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of and priority
from European Patent Application Serial No. EP 07400034.0, filed
Dec. 20, 2007, the entire disclosure of which is hereby
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a smoking article with improved
extinguishing characteristics (reduced or lower ignition propensity
or ignition proclivity) and to a method of manufacturing such a
smoking article.
[0004] 2. Discussion of the Prior Art
[0005] Product regulations in many countries specify that
cigarettes have to fulfil certain safety standards regarding their
ignition propensity. The ignition propensity of cigarettes can be
measured by a standardized test method. Usually, the test defined
in ASTM E 2187-04 is performed (ASTM: "American Standard for
Testing and Materials"; ASTM E 2187: "Standard Test Method for
Measuring the Ignition Strength of Cigarettes"; the extension "-04"
refers to 2004 as the year of the last revision). According to ASTM
E 2187-04, a sample of 40 cigarettes is tested under well-defined
conditions, and the fraction of these cigarettes which burn their
full length is called "the test result". A safety standard
specifies which test result is acceptable. For example, in Canada
and some U.S. states, the acceptable test result is 25%, i.e., at
least 75% of the cigarettes have to extinguish before burning their
full length in order to comply with the safety standard.
[0006] The most common way to reduce the ignition propensity of
cigarettes is to enhance the extinguishing characteristics by using
a paper wrapper comprising spaced bands of lower porosity, which
extend along the circumference of the wrapper. By these means,
oxygen supply is reduced when the burning cone of the cigarette
reaches a respective band, and the cigarette extinguishes when
smoldering on a substrate, as described in ASTM E 2187-04. Common
methods to produce such banded cigarette papers are described in EP
1 234 514 A2.
[0007] A general disadvantage of using low-porosity bands on
wrapper papers is a reduced rod ventilation caused by the reduced
porosity in these bands, resulting in changes of CO/NFDPM ratios to
often undesired levels (CO: carbon monoxide, NFDPM: nicotine-free
dry particulate matter).
[0008] The use of inorganic salts as burn retardants is commonly
known, including some applications for tobacco products. Inorganic
salts as such, however, have not been used for reducing ignition
propensity, which is probably based on the assumption that a
certain oxygen deficit is necessary to make cigarettes
self-extinguish in the ASTM test cited above and that this can only
be achieved by reducing the wrapper porosity to a level lower than
10 CU to 15 CU (CU: Coresta unit, permeability as measured in the
tobacco industry, see CORESTA Recommend Method No. 40). In EP 1 234
514 A2, for example, ammonium phosphate is used as a burn
retardant, but only in combination with additional substances, as
e.g., alginates, which provide for a low porosity.
SUMMARY
[0009] The object of the invention is to provide a smoking article
with reduced ignition propensity, which does not exhibit the
disadvantage of a significantly reduced rod ventilation.
[0010] According to one aspect of the present invention, a smoking
article is provided that includes a tobacco rod and a wrapper. The
wrapper includes at least one zone treated with an inorganic salt
providing reduced ignition propensity.
[0011] Another aspect of the present invention concerns a method of
manufacturing a smoking article that includes a tobacco rod and a
wrapper, where the wrapper includes at least one zone treated with
an inorganic salt providing reduced ignition propensity. The method
includes the step of applying the inorganic salt to the wrapper by
a solution or a suspension.
[0012] According to an additional aspect of the present invention,
a paper is provided that is formed as a wrapper for rolling a
cigarette that includes a tobacco rod, wherein the wrapper is
configured to radially surround the rod. The paper includes at
least one zone treated with an inorganic salt providing reduced
ignition propensity. The paper may be formed as a tube and may
include a filter.
[0013] This summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the detailed description of the preferred embodiments. This summary
is not intended to identify key features or essential features of
the claimed subject matter, nor is it intended to be used to limit
the scope of the claimed subject matter.
[0014] Various other aspects and advantages of the present
invention will be apparent from the following detailed description
of the preferred embodiments and the accompanying drawing
figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0015] A preferred embodiment of the present invention is described
in detail below with reference to the attached drawing figures,
wherein:
[0016] FIG. 1 is a perspective view of a smoking article
constructed in accordance with the principles of one embodiment of
the present invention, particularly depicting a wrapper with a
treated zone;
[0017] FIG. 2 is a perspective view of a smoking article
constructed in accordance with the principles of another embodiment
of the present invention, particularly depicting a wrapper with
multiple treated zones; and
[0018] FIG. 3 is a perspective view of the smoking article of FIG.
2, depicting the smoking article in an ignited condition.
[0019] The drawing figures do not limit the present invention to
the specific embodiments disclosed and described herein. The
drawings are not necessarily to scale, emphasis instead being
placed upon clearly illustrating the principles of the preferred
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The present invention is susceptible of embodiment in many
different forms. While the drawings illustrate, and the
specification describes, certain preferred embodiments of the
invention, it is to be understood that such disclosure is by way of
example only. There is no intent to limit the principles of the
present invention to the particular disclosed embodiments.
[0021] A smoking article 10 according to one embodiment of the
invention comprises a tobacco rod 12 and a wrapper 14. The wrapper
14 includes at least one zone 16 treated with an inorganic salt
providing reduced ignition propensity. This zone 16 can comprise
the total wrapper 14. In advantageous embodiments of the invention,
however, the wrapper 14 includes at least one discrete zone 18
treated with the inorganic salt, wherein the total surface area of
the discrete zones 18 is smaller than the total surface area of the
wrapper 14, i.e., in addition to any areas of the wrapper 14 being
covered by, e.g., a tipping paper of a filter 20, there are exposed
areas 22 of the wrapper 14 which are not treated with the inorganic
salt.
[0022] Surprisingly, it was found that the application of inorganic
salts is able to reduce the ignition propensity of the smoking
article 10 without reducing the porosity of the wrapper 14 to
levels as commonly required for this purpose. Thus, the invention
does not rely on the main effect of a reduced porosity in the zones
18 treated with the inorganic salt.
[0023] In advantageous embodiments of the invention, the porosity
of the wrapper 14 in the treated zones 18 is larger than 10 CU,
preferably larger than 12 CU, or larger than 15 CU. Porosities in
this range permit access of sufficient oxygen to the tobacco rod 12
in order to minimize carbon monoxide formation and provide for
sufficient diffusion.
[0024] The inorganic salt can comprise, e.g., magnesium chloride,
aluminum sulfate, alum, sodium tetraborate, hydrated magnesium
chloride, hydrated aluminum sulfate, hydrated alum, hydrated sodium
tetraborate, sodium chloride, or mixtures thereof. In the discrete
zones 18 of the wrapper 14, the specific amount of the organic salt
can be in the range of from 0.2 mg/cm.sup.2 to 20 mg/cm.sup.2, or
in the range of from 0.5 mg/cm.sup.2 to 5 mg/cm.sup.2. Moreover,
any interval limits in the range of from 0.2 mg/cm.sup.2 to 20
mg/cm.sup.2 are explicitly disclosed herewith. Such inorganic salts
are less expensive than porosity-reducing agents like
alginates.
[0025] In advantageous embodiments of the invention, there are
discrete zones 18 treated with the salt(s) arranged as bands
(rings) 24 extending along the circumference of the smoking article
10 and having a width, measured along the tobacco rod axis 26, of
from 2 mm to 12 mm, or from 2 mm to 8 mm, or preferably of 6 mm.
Generally, the provision of the inorganic salts in the bands 24 is
sufficient for achieving reduced ignition propensity such that it
is not required to treat the whole wrapper material with the
inorganic salt, which results, e.g., in cost reduction and the
possibility of an even higher porosity in the wrapper areas 22
between the discrete zones 18. Preferably, the wrapper 14 comprises
at least two such bands 24 which are separated by at least 1 mm, or
at least 5 mm, and preferably by at least 10 mm.
[0026] In advantageous embodiments of the invention, the smoking
article 10 comprises a filter 20, and the smoking article 10 can be
designed as a cigarette, wherein the wrapper 14 is a cigarette
paper (which includes the possibility of manufacturing the wrapper
from reconstituted tobacco).
[0027] Other embodiments of the invention relate to a paper for
rolling cigarettes (RYO cigarettes; RYO: "Roll Your Own"), as well
as to a paper tube (preferably a paper tube including a filter at
one of its ends) for making cigarettes (MYO cigarettes; MYO: "Make
Your Own") by filling the paper tube with tobacco. In these cases,
the rolling paper and the paper tube comprise, with respect to
reduced ignition propensity, the features of the wrapper of a
smoking article explained so far.
[0028] There are several ways of manufacturing a smoking article 10
according to the invention, in particular of applying the inorganic
salts to the wrapper 14. These methods can be applied to a paper
for rolling cigarettes or to a paper tube for making cigarettes in
an analogue way.
[0029] In advantageous embodiments, the inorganic salt is applied
to the wrapper 14 by means of a solution or suspension. To improve
the solubility of the inorganic salt, such solution can be heated.
Preferably, the solvent or the suspension agent comprises
water.
[0030] The inorganic salt can be applied to the wrapper 14 by,
e.g., printing techniques like gravure printing or inkjet printing,
but also techniques like spraying or sizing. Printing techniques
are very precise and can even be used online, e.g., in a cigarette
making process after wrapping a continuous tobacco rod 12 with the
wrapper material.
[0031] For example, the inorganic salt can be applied to the
wrapper 14 by sizing in a papermaking process for providing the
material of the wrapper 14. Whereas, usually, sizing is applied to
the overall surface of the paper produced in a papermaking process,
it is also possible to size zones of the paper only.
[0032] In another possibility, the inorganic salt is applied to the
wrapper 14 immediately after a papermaking process during the
cutting step of a mother reel into bobbins containing wrapper
material, as usually performed in the cigarette paper industry in
order to provide wrapper material suitable for use in a cigarette
making machine.
[0033] When a bobbin containing ordinary wrapper material is
provided, the inorganic salt can be applied to the wrapper material
during a rewinding step of such bobbin. This step is performed
offline, i.e., not during the usual operating steps of a cigarette
making machine.
[0034] It is also possible to apply the inorganic salt to the
wrapper 14 during a cigarette making process, i.e., online, either
before wrapping a continuous tobacco rod 12 with the wrapper
material or after wrapping a continuous tobacco rod with the
wrapper material. For such applications, gravure printing and
inkjet printing, which apply a solution or suspension of the
inorganic salt as "ink", are particularly suitable.
[0035] In the following, the invention is described in more detail
by means of several embodiments, which are not considered as
exclusive.
EXAMPLE A
[0036] In a pilot test, cigarette papers were homogeneously treated
with inorganic salts, and the porosity of the respective cigarette
paper was measured before the treatment and after the treatment.
The porosity measurements were performed according to CORESTA
Recommended Method No. 40. 1 CU ("CORESTA unit") is the air flow
(in cm.sup.3/min) through an area of the cigarette paper of 1
cm.sup.2 when the pressure difference across the cigarette paper is
1 kPa. The following table shows the initial porosity ("base
porosity") of the cigarette paper, the salt and its amount applied
as well as the porosity after the salt treatment ("remaining
porosity").
TABLE-US-00001 Remaining Base Porosity Salt Amount Porosity 35 CU
Magnesium chloride (hydrate) 1.2 mg/cm.sup.2 16 CU 35 CU Aluminum
sulfate (hydrate) 3.0 mg/cm.sup.2 11 CU 35 CU Sodium chloride 4.0
mg/cm.sup.2 64 CU 50 CU Aluminum sulfate (hydrate) 3.0 mg/cm.sup.2
18 CU
[0037] It is evident that the remaining porosity is larger than 10
CU in all cases and significantly larger than 10 CU in most of the
cases.
EXAMPLE B
[0038] In another test, a commercial cigarette comprising a
cigarette paper with a base porosity of 35 CU was homogeneously
treated with an aqueous solution of sodium chloride until a weight
of 4.0 mg sodium chloride per cm.sup.2 was achieved.
[0039] The test result according to ASTM E 2187-04 (see above) for
cigarettes treated in this way was 35%.
EXAMPLE C
[0040] The outer side ("felt side") of a commercial cigarette paper
(base porosity 35 CU) was sprayed with an aqueous solution of
magnesium chloride to form treated discrete zones in band form of 6
mm width with a distance (gap width) of 20 mm on the paper. The
concentration of the solution and the amount of spraying were
adjusted so that a weight of 1.2 mg magnesium chloride per cm.sup.2
was achieved. In other embodiments, the inner side ("wire side") or
both sides of the cigarette paper could be sprayed with the
solution.
[0041] Conventional American Blend cigarettes were produced with
the treated paper and tested according to ASTM E 2187-04. The test
result was 13%.
EXAMPLE D
[0042] A warm (50.degree. C.), saturated solution of aluminum
sulfate was applied to the cigarette paper (porosity 50 CU) of a
conventional cigarette during the cigarette making process using a
gravure printing device. The gravure depth was adjusted so that a
weight of 3 mg aluminum sulfate per cm.sup.2 was achieved in the
printed areas. The salt was applied in band-shaped discrete zones
having a width of 6 mm each and a respective distance (width of
untreated zones) of 20 mm.
[0043] According to ASTM E 2187-04, the test result was 20%.
[0044] The preferred forms of the invention described above are to
be used as illustration only, and should not be utilized in a
limiting sense in interpreting the scope of the present invention.
Obvious modifications to the exemplary embodiments, as hereinabove
set forth, could be readily made by those skilled in the art
without departing from the spirit of the present invention.
[0045] The inventors hereby state their intent to rely on the
Doctrine of Equivalents to determine and access the reasonably fair
scope of the present invention as pertains to any apparatus not
materially departing from but outside the literal scope of the
invention set forth in the following claims.
* * * * *