Smoking Articles

Abstract

A cigarette having a filling which includes a first portion of shredded natural tobacco and a second portion, of different constitution, comprising shredded natural tobacco, reconstituted tobacco, tobacco substitute and/or filler. The said portions adjoin each other at a surface inclined in relation to the axis of the article. The two portions may be wedge shaped and adjoin each other at a plane inclined in relation to the longitudinal axis of the article. Alternatively, one portion is a core of conical or frusto-conical shape and is surrounded by the other portion.

Description

This invention concerns improvements relating to smoking articles of the nature of cigarettes, cigarillos, cigars and pipe charges. It is applicable with particular advantage to cigarettes.

It is an object of the invention to provide a smoking article in which the delivery of smoke components, for example of total particulate matter, nicotine and/or gas-phase components, on smoking can be selected.

According to the invention, a smoking article has a filling which includes a first portion of shredded natural tobacco and a second portion of different constitution, comprising shredded natural tobacco, reconstituted tobacco, tobacco substitute and/or filler, the said portions adjoining each other at a surface inclined in relation to the axis of the cigarette. The article is preferably of conventional overall dimensions and wrapped in conventional manner, for example in cigarette paper.

In one embodiment of the invention, the two portions adjoin at a plane inclined in relation to the axis, thus forming two wedge-shaped portions of equal or unequal size.

In another embodiment, one said portion is a core of conical or frusto-conical shape and is surrounded by the other portion.

Embodiments of the invention by way of example will now be more fully described with reference to the accompanying drawing, in which

FIGS. 1 to 3 are diagrammatic longitudinal sections through three such embodiments:

The filling of the cigarette 1 shown in FIG. 1, which has a normal paper wrapper 2, comprises two wedge-shaped portions 3 and 4 which adjoin each other at a plane 5 inclined in relation to the longitudinal central axis of the cigarette. The plane 5 extends to the two ends of the cigarette which it intersects at diametrically opposite points. The two portions 3 and 4, which are thus of equal volume consist of different shredded materials one of which is natural tobacco and the other a reconstituted tobacco, a tobacco substitute, a filler, a natural tobacco different from the first-named tobacco or a mixture of any two or more of the materials referred to. If the end 6 of the cigarette is that intended to be placed in the smokers mouth, which may be indicated by colour, printed matter or the like, preferably the portion 3 has the filling of the first named, natural tobacco and the portion 4 the filling of the other material. However, such a cigarette can be smoked from either end.

The plane 5 need not extend to the ends of the cigarette. As shown for the cigarette 7 in FIG. 2, the intersection may be at points short of the said ends. The intersection may be equally or unequally short of the two ends. Indeed, at one end, the plane 5 may extend to the end of the cigarette as in FIG.1. If the plane 5 is symmetrical in relation to the two ends, the volumes of the portions 3,4 will be equal. An asymmetrical arrangement allows of the selection of portions 3,4 of different volumes in order to select the delivery of the smoke components in predetermined manner. Generally the portion 3 will preferably have the larger volume.

In the kind of cigarette 8 shown in FIG. 3, the two portions 3 and 4 are separated by the surface of a cone or, as shown, of a frustum of a cone. The cone or frustum may terminate short of either end of the cigarette. In the example illustrated, the cone surface 9 intersects the circumference of the cigarette at one end and intersects the other end in a circular end region 10. Such a cigarette can be smoked from either end, but preferably from the end 6. The portions 3 and 4 have different fillings, as described above. Preferably, however, the core portion 3 of frusto-conical shape contains natural tobacco, while the portion 4 complementing the core within the cylindrical wrapper 2 contains reconstituted tobacco, tobacco substitute and/or filler. The volumes of the portions 3 and 4 may again be selected to select the delivery of the smoke components. For practical reasons, a paper wrapper of the shape of the surface 9 may separate the portions 3,4.

With the cigarette of FIG. 3, the surface 9 need not be strictly that of a right-circular zone. The surface may, for example be slightly concave or convex. In all of the examples, the cigarette may be of slightly oval cross section.

Cigarettes of the kind illustrated in FIG. 1 have been tested for the delivery of particular smoke constituents. The cigarettes tested were machine made to a length of 70 mm and a circumference of 25 mm. Smoking was carried out under standard machine-smoking conditions, namely to a 23 mm butt length at a rate of 1 puff of 2 seconds duration every minute, and 35 ml volume.

1. In a first test, the portion 3 of the cigarette 1 contained shredded natural tobacco and the portion 4 a filler which would be non-combustible by itself and consisted of 76 percent by weight of calcium carbonate, 7 percent of carboxymethyl cellulose as binder, 2 percent of glycerol and 15 percent of tobacco extract. A dispersion in the form of a slurry was prepared, which was dried and cut to shred form.

For comparison purposes a control cigarette of the same dimensions was filled with an intimate mixture of 75 percent of the same tobacco and 25 percent of the same filler. This proportion was selected to take account of the unsmoked 23 mm butt. As may be seen from FIG. 1, in which the butt length is indicated at 11, a substantially greater proportion of tobacco from 3 than of filler from 4 will be burnt when smoking is terminated at the said butt length. The aforesaid proportions were selected to compensate for this difference and to ensure substantially the same nicotine delivery in the two cases. It was found that the total particulate matter (TPM) passed by the test cigarette was 22 mg per cigarette as compared with 28 mg for the control cigarette, while the nicotine delivery was the same at 1.55 mg. This test shows that the TPM can be reduced, while the nicotine delivery is kept constant.

2. A similar test cigarette 1 had the portion 3 filled with natural tobacco and the portion 4 with a known reconstituted tobacco made in sheet form by a paper-making process and containing 50 percent chalk filler. A control cigarette was filled with an intimate mixture of equal proportions of the same natural tobacco and reconstituted tobacco. The total delivery of nicotine alkaloids by the test cigarette was found to be 2.1 mg per cigarette, as compared with 1.7 mg for the control cigarette.

3. A similar cigarette 1 was prepared except that the portion 4 contained a known synthetic smoking material. A control cigarette contained an intimate mixture of equal proportions of the same constituents. The delivery of nicotine alkaloids was 2.2 mg per test cigarette as compared with 1.7 for the control cigarette.

4. A test similar to test 2 was carried out with a cigarette having the same external dimensions and constituents, but of the kind described with reference to FIG. 2, the plane 9 terminating 10 mm short of each end of the cigarette. The delivery of nicotine alkaloids was again 2.1 mg, as compared with 1.7 for the control cigarette.

Tests 2, 3 and 4 show that the delivery of total nicotine alkaloids can be increased for a given total amount of tobacco in the cigarette, thus providing a means for increasing the transfer of nicotine to the smoke without recourse to chemical additives.

5. In a test conducted upon a cigarette having the same form and constituents as in Test 1, the TPM deliveries from a series of pairs of puffs were separately measured for comparison with those of a control cigarette containing an intimate mixture of equal proportions of the same constituents. The results were as follows:

TPM Deliveries (mg) Test Control Puffs 1 and 2 6 4 " 3 and 4 6 6 " 5 and 6 6 8 " 7 and 8 7 8

In the case of the test cigarette, the TPM delivery remained almost constant through the smoking of the cigarette, in contrast with an appreciable increase in the case of the control cigarette.

6. A cigarette having the same form and constituents as in Test 1 was found to give a delivery of hydrogen cyanide of 500.mu.g as compared with a delivery of 590 .mu.g from a control cigarette containing an intimate mixture of equal proportions of the same constituents. It is apparent that the delivery of vapor-phase smoke constituents, as measured by the hydrogen-cyanide delivery, can be substantially reduced.

7. A cigarette of the form shown in FIG. 3 was made, by hand, with a length and circumference of 70 and 31 mm respectively, the circumference of the end region 10 of the core portion 3 being about 19 mm. The portion 3 contained tobacco and the portion 4 the aforesaid non-combustible filler, the proportions of these constituents being 76 to 24. A control cigarette of the same external dimensions contained an intimate mixture of the same constituents in the same proportions. The delivery of T.P.M. was 19 mg in the case of the test cigarette and 27 mg in that of the control cigarette.

The results of these tests show that the delivery of various smoke constituents can be changed by using different distributions of the same materials in the same or equivalent proportions. Accordingly, the invention provides a simple readily applicable means for selecting these deliveries in a predeterminable manner.

If desired, cigarettes such as have been described may be provided with a filter or mouthpiece.

Claims

I claim:

1. A cigarette having a filling consisting of two portions, each of which extends continuously throughout the length of said filling, namely, a first portion of shredded natural tobacco and a second portion, of different constitution, selected from the group consisting of shredded reconstituted tobacco, tobacco substitute and filler, the portions adjoining each other at a surface inclined in relation to the axis of the cigarette with 100 percent of the first portion material at the end remote from the end to be nearer to the smoker's mouth and 100 percent of the second portion material at the end to be nearer to the smoker's mouth, whereby selected delivery of the smoke components is achieved throughout smoking of the cigarette.

2. The invention in accordance with claim 1 wherein the two portions are wedge-shaped and adjoin each other at a plane inclined in relation to the longitudinal axis of the cigarette.