Tobacco – Tobacco or tobacco substitute product or component part thereof – Cigar or cigarette
Reexamination Certificate
1999-10-06
2001-03-20
Derrington, James (Department: 1731)
Tobacco
Tobacco or tobacco substitute product or component part thereof
Cigar or cigarette
C131S329000, C131S330000, C131S351000, C131S349000, C131S359000, C131S364000, C131S084100, C131S084200
Reexamination Certificate
active
06202651
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to smoking articles, such as cigarettes, for example, and methods of producing such articles.
2. Brief Description of the Related Art
The reduction of sidestream smoke produced by smoking articles has been a recent objective in the tobacco industry. Conventional methods thus far have centered on the identification and addition of sidestream reducing compounds either into the paper structure at the paper making stage or by coating of water-soluble sidestream reducing compounds onto the paper after manufacture; for example U.K. Patent Specification No. 2 139 869. The use of paper filler substances, such as magnesium oxide, in combination with low levels of alkali metal salts have also been proposed in U.S. Pat. No. 4,231,377. A more recent development has been the achievement of reduced sidestream smoke deliveries by providing a cigarette with a circumference within a range of 10 mm to 19 mm, a free burn rate of 25 mg min
−1
to 50 mg min
−1
, and a tobacco packing density of 150 mg cm
−3
to 350 mg cm
−3
as has been disclosed in U.K. Patent Specification No. 2 175 789B.
In the past, cigarettes have been proposed having an inner core or filament surrounded by a layer of tobacco material. British Patent Specification No. 2 070 409 discloses a lengthwise extending filament which may be of an expanded reconstituted tobacco material treated with smoke-modifying agent. British Patent Specification No. 2 119 628 discloses a lengthwise extending line of expandable tobacco paste within a rod of cut tobacco material. The rod is heated and the tobacco line expands, compressing the tobacco thereabout. Lower density packing levels of the annulus of conventional tobacco material can thus be obtained.
French Patent Specification No. 998,556 discloses an inner core consisting of low quality tobacco and an annular layer of higher quality tobacco than the core. Savings in material costs are said to be achieved from such an arrangement. Further embodiments of coaxial cigarettes are described in French Patent Specification No. 1,322,254 and U.S. Pat. Nos. 1,829,559 and 4,716,913.
Cigarettes having a wrapped core are also known from U.S. Pat. No. 3,190,287, which relates to providing a by-pass arrangement in the smoking material rod for the mainstream smoke, and British Patent Specification No. 1 228 747, which relates to the selective filtration of polycyclic hydrocarbons from the mainstream smoke.
None of these documents deal with the concept of reducing sidestream smoke components of a combustible smoking article.
More recently, German Patent Application No. P38 36 210 disclosed a coaxial plain cigarette having an inner core of predominantly residue-free smoulderable material, especially tobacco, with a wrapper for the inner core, and an outer layer of tobacco and/or non-tobacco material coaxially surrounding the inner core and its wrapper, with a wrapper for the outer layer. The characteristics of the paper and tobacco rods are balanced to ensure a lower smoulder rate than in conventional cigarettes (less than 2 mm/min). Consequently a reduction in the amount of sidestream smoke produced per unit of time occurs during the inter puff period. However, the cigarette burns continuously in a conventional manner with a glowing coal, i.e. there is no part of the cigarette which is extinguished or extinguishes during puffing or smoulder.
Very recently, European Patent Application No. 0 380 324 disclosed a rod of smoking material wrapped in a wrapper and having extending coaxially therealong, over a great proportion of the rod length, a rod of activated carbon. The purpose of this rod, it is asserted, is to provide a clean-burning smoulder element which maintains free smoulder whilst the surrounding tobacco material extinguishes. As an alternative to the axial rod, a sheath wrapper also composed of activated carbon, can be used to enclose a conventional tobacco rod. The smoking material annulus or tobacco rod extinguishes in the inter-puff period and is re-ignited by the increased burning of the smoulder element due to the drawing in of oxygen when the cigarette is puffed upon. A drawback of this proposal is that the carbon element will have a disadvantageous effect on the mainstream carbon monoxide delivery. Also, it is to be expected that there would be an unacceptable carbon off-taste in the mainstream smoke delivered to the smoker. Furthermore, because of the fragile nature of the carbon rod, it may easily be broken during manufacture. The position of the carbon rod so that it cannot be seen by the smoker at the lighting end of the cigarette, in order to present a conventional rod end to the smoker, will also make for manufacturing difficulties.
It is an object of the present invention to provide alternative smoking article constructions without the disadvantages seen in the prior art documents, which constructions have the advantage of a reduced, or possibly negligible, inter-puff sidestream production, yet which can resume normal smoking characteristics when the article is drawn upon.
Cigarettes according to the present invention seek to use the tobacco material therein in a more effective manner, so that no tobacco or substantially less than the normal amount of tobacco is wasted in the inter-puff period.
SUMMARY OF THE INVENTION
One aspect of the present invention provides a smoking article comprising a rod of combustible material wrapped in a wrapper, which rod is provided with an inter-puff region capable of maintaining smoulder in the inter-puff period, and a puff region comprising tobacco-containing material, the inter-puff region being capable of re-igniting a further puff region spaced from the first puff region.
Another aspect of the present invention provides a smoking article comprising a rod of combustible material wrapped in a wrapper, which rod is provided with an inter-puff region capable of maintaining smoulder in the inter-puff period whilst adjacent smoking material is substantially extinguished, the region extending lengthwise of the rod of combustible material and being comprised of cut tobacco or tobacco-containing material, said region being capable of re-igniting the adjacent smoking material when the article is drawn upon in a puff.
The puff region may include material which is also present in the inter-puff region and may comprise the same material as the inter-puff region.
In the first aspect of the invention the inter-puff region may be comprised wholly of non-tobacco material such as binders, inorganic fillers, such as perlite or chalk, carbon or carbonised material, activated carbon, starch or modified starch, cellulose or modified cellulose, and chemical additives which decompose on heating to release oxygen and promote burning, or compounds which release volatile substances, flavourings, for example. Mixtures of all of these materials are also suitable for the inter-puff region. The non-tobacco material may, for example, be produced by an extrusion process.
Alternatively, in both the first aspect and, in particular, the second aspect of the invention, the inter-puff region may be comprised wholly of tobacco material, such as reconstituted tobacco material, tobacco powder, tobacco fines or cut tobacco leaf material (lamina and/or stem).
Such tobacco material may also be mixed with non-tobacco material such as described above to provide tobacco-containing filler material. The tobacco-containing inter-puff region may be an extrudate material extending lengthwise of the rod of combustible material. The extrudate material may suitably be a foamed extrudate material, preferably of an open cell structure to allow draw therealong.
The rod of combustible material in the first aspect of this invention may suitably comprise areas of high levels of tobacco material (puff region) adjacent areas of low levels of tobacco material (inter-puff region). In such instances, the rod of combustible material may have a segmented or bulbous appearance. Each segment having a high level of t
Kinnard Philip John
Luke John Anthony
British-American Tobacco Company Limited
Colaianni Michael P.
Derrington James
Pitney Hardin Kipp & Szuch LLP
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