Tobacco – Tobacco or tobacco substitute product or component part thereof – Cigar or cigarette
Reexamination Certificate
1999-09-09
2001-07-10
Silverman, Stanley S. (Department: 1731)
Tobacco
Tobacco or tobacco substitute product or component part thereof
Cigar or cigarette
C131S365000, C131S364000, C131S341000, C131S344000, C131S349000
Reexamination Certificate
active
06257243
ABSTRACT:
The present invention relates to smoking articles and in particular to cigarettes having reduced formation of spots and less sidestream smoke.
If cigarettes are stored for a long period of time, then formation of spots on the cigarette paper may occur. This formation of spots is caused by particular substances in or on the smokable material, which may comprise cut tobacco material, of the cigarette, which substances over a long period of time can pass through the paper to the outer surface thereof so that spots or discoloured regions form on the cigarette paper. This results in a negative visual impression to the consumer.
The smoke formed when a cigarette is smoked is typically divided between mainstream smoke and sidestream smoke. The sidestream smoke is that smoke which does not pass through the filter into the mouth of the smoker and thus is that smoke produced by the wasteful burning of the cut tobacco material. Thus, and also from the point of view of reducing the smoke passing into the surroundings, it is desirable to ensure that as small a fraction as possible of sidestream smoke is produced when a cigarette is smoked.
It is an object of the present invention to describe a cigarette which, on the one hand, is less liable to the formation of spots on the paper thereof. It is a further object to produce a cigarette which, on the other hand, produces less sidestream smoke than conventional cigarettes when smoked.
Either or both of these can be achieved by a cigarette with the characteristics in accordance with claim
1
.
The secondary claims relate to specific applications of the invention.
This invention provides a cigarette formed as a coaxial cigarette with a coaxial rod of tobacco, the inner segment of which contains a smokable material which is surrounded by a covering. Around the covering of the inner segment is an outer segment of combustible or thermally destructible/decomposable material. This outer segment of combustible or thermally destructible material is surrounded by a further covering. The combustible material of the outer segment contains no, or only a small fraction of, spot-forming substances. The layers surrounding the inner segment of the coaxial strand, namely the inner covering, the outer segment and the external covering, are so constructed that the spot-forming substances which are present in the inner segment are, in principle, unable to reach the outer surface of the outer covering. This can be achieved by, for example, the inner segment being surrounded by a covering having only a very low permeability or being impermeable to spot-forming substances. Furthermore, it is also possible that the inner and outer coverings together with the external segment form a type of barrier to spot-forming substances so that, for example, substances which pass through the inner covering are taken up by the external segment and are prevented from passing therethrough. The substances are thereby prevented from reaching the external covering. In addition, it is also possible that the external covering is such that it prevents spot-forming substances which migrate through the inner covering and the external segment from reaching the outer surface of the external covering, hence no spots are formed thereon.
Materials particularly suitable for use in the outer segment are, for example, tobacco(s) having very low petroleum ether extractables. Suitable materials for the outer segment include clay materials, carbonates such as, for example, calcium carbonate, other mineral components or tobacco with a high fraction of mineral components. All such materials show no or only very slight tendency to form spots and they also ensure that only relatively few spot-forming substances can migrate from the inner segment to the outer covering.
During smoking of a cigarette, the smoke from the smokable material of the inner segment is largely consumed by the smoker. This is due to the properties of the inner covering, the outer segment and the outer covering, which are designed such that the smoke is maintained inside the coaxial rod and thus only a low amount of sidestream smoke can escape from the coaxial rod. The outer segment consists of combustible material or material that is thermally destructible such that the outer segment is degraded together with the inner segment during smoking, but only a relatively small amount or no particulate phase components are produced from the material of the outer segment.
Thus the smoke actually consumed by the smoker is that arising from the inner segment of the cigarette, while the smoke components from the combustible or thermally destructible material of the outer segment pass through the peripheral region of the cigarette. The fraction which is valueless to the smoker also has no adverse effects on, for example, the taste of the cigarette and can be removed from the smoke stream by, for example, filters.
The coaxial rod can be formed concentrically so that the inner and outer segments are circular and have a common centre point. As a person skilled in the art would readily appreciate, it is also possible that one of the two segments is elliptical or rectangular in shape. Of course, other shapes are also possible. It is important however that the inner segment is completely surrounded by the covering of the inner segment, the outer segment and the covering of the outer segment so that because of these three layers, on the one hand, the spot-forming substances from the inner segment cannot reach the outer surface of the outer covering and, on the other hand, it is ensured that when the coaxial cigarette is smoked, only relatively low amounts of the smoke produced by the material of the inner segment is lost as sidestream smoke.
The inner segment thus serves to provide smoke with an acceptable flavour while the three layers arranged around the inner segment serve to reduce or prevent the formation of sidestream smoke and to reduce or prevent the formation of spotting.
Advantageously, only the inner segment contains material(s), particularly tobacco, treated with casings, including humectants, since these materials can result in a relatively high proportion of spot-forming substances. If the material of the outer segment contains no casing(s) then the spot-forming substances in the inner segment are shielded from the outer surface of the outer covering by the three layers between them, that is to say that the three layers represent a barrier to the spot-forming substances.
Preferably the inner coaxially arranged segment contains between 5 and 40% by weight casings. If the inner segment contains, for example, 40% by weight of an aromarich casing then, because of this high proportion of casing in the inner segment, the smoke produced has a very intense flavour when the coaxial cigarette is smoked. Since in accordance with this invention the material reaching the smoker is mainly from the inner segment of the coaxial cigarette, while the material in the outer segment contributes relatively little to the smoke, the coaxial cigarette, in comparison with a conventional cigarette of the same circumference, produces the smoke to be consumed from a smaller segment of smokable material. This effect can be compensated for by the high proportion of casings and the intense flavours produced therefrom. The components usually used as casings include, for example, sugars, cocoa and liquorice.
The packing density of the smokable material in the inner segment is preferably in the range of 200 mg/cm
3
to 320 mg/cm
3
, and more preferably in the range of 240 mg/cm
3
to 280 mg/cm
3
. The packing density may be selected tobacco-specifically, so that in production a stable inner rod is formed.
The pressure drop in the inner segment is preferably in the range of 100 mm WG to 200 mm WG, particularly in the range of 140 mm WG to 160 mm WG.
Advantageously, the inner segment contains particularly aromatic tobacco(s) such as, for example, the so-called “Aroma Grades”, at at least 40% thereof. In this way it can be ensured that smoke produced from the inner segment whe
Cook Christopher John
Muller Bernd-Henrik
Schluter Adolf
Schneider Werner
St. Charles Frank Kelley
Brown & Williamson Tobacco Corporation
Middleton & Reutlinger
Salazar John F.
Silverman Stanley S.
Walls Dionne A.
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