IE45866B1 - Smoking article - Google Patents

Abstract

A smoking product consisting of tobacco or the like, for example a cigarette, cigar or cigarillo, at least partially comprises a low-density filling material with a high degree of filling. The smoking product has means in order to channel air from the atmosphere into the smoke stream so that the number of draws necessary for smoking the smoking product is increased.

Description

This invention concerns improvements in or relating to smokers articles such as cigarettes, cigarillos and cigars containing a smoking material such as tobacco, reconstituted tobacco sheet or synthetic smoking material.

Xt is known that the intrinsic density of cigarette, cigarillo and cigar filler materials can be decreased so that when used in place of untreated filled material the packing density in these smoking articles may be considerably reduced while retaining an adequate degree of firmness.

There is a high degree of correlation between the tar and nicotine yields of modern cigarettes, so that a low tar yield generally means a low nicotine yield. A consequence of this is that if a smoker changes from a high or middle tar brand to a low tar brand the nicotine yield is no longer of an acceptable level. It is therefore a desirable object that cigarettes be developed that have reduced tar yields but maintain nicotine yields above a minimum acceptable level.

Xt is known that raising the nicotine content of the tobacco filler in a cigarette leads to a reduction in the tar: nicotine ratio of the smoke. However, the nicotine content of normal tobacco filler cannot be raised to very high levels because, even after filtration or dilution of the mainstream smoke to give acceptable nicotine yields, the side-stream smoke nicotine yield 866 - 3 remains at an unacceptably high level. Mainstream smoke is that smoke which is drawn by the smoker through the cigarette into the smoker's mouth; side-stream smoke is that smoke which drifts off from the cigarette into the ambient air.

In a cigarette containing filler of decreased intrinsic density (e.g. expanded tobacco filler), the lower weight of filler consumed during smoking results in lower yields of nicotine in both mainstream and side-stream smoke. Expanded tobacco filler can therefore be provided with a higher nicotine content than would be acceptable with normal, un-expanded tobacco filler, thereby reducing the tar: nicotine ratio further than has hitherto been thought possible.

A disadvantage of the use of such lower density, higher filling capacity filler materials in e.g. cigarettes is a reduction in the number of puffs required to smoke the article. Most of the reduction in puff number arises from the reduction in filler weight but there is a slight increase in the rate of burn when the density of filler is reduced, so that puff number will be decreased still further. Reduction in puff number is, in general, not acceptable to the smoker.

It is an object of the present invention to reduce and in some instances eliminate the reduction in puff number caused by the use of lower density, higher filling value filling materials, thus enabling the production of acceptable cigarettes having a lower tar yield but higher nicotine yield than is hitherto obtainable.

It is found that the use of expanded out tobacco lamina in a tobacco blend results in a reduction in the smoke carbon monoxide yield. However, as discussed above, the use of an expanded tobacco in a cigarette reduces the puff number to an unacceptable degree.

It is a further object of the present invention - 4 to provide a means of reducing the smoke carbon monoxide yield when using expanded tobacco without however reducing the puff number of the cigarette containing expanded tobacco.

It is possible to increase the puff number of a cigarette by a variety of methods as follows: The dimensions of the cigarette may be changed; this is unattractive because it may result in the dimensionally altered cigarette being placed in a price range unacceptable to a smoker.

The grade of tobacco may be varied; this can result in a flavour change unacceptable to the smoker.

A different tobacco from another source may be used. This approach is not acceptable because such a tobacco may be difficult or more expensive to obtain and may have undesirable flavour or other characteristics.

A finer strand width may be used but this results in a product of unacceptable softness.

The moisture content of the tobacco may be increased, but this has a deleterious effect on the shelf life of the tobacco in that the tobacco is likely to dry out to its normal level, thereby decreasing its puff number. Further, unduly high moisture levels result in unacceptable flavours or mould formation.

Additives may be put into the tobacco. There are technical difficulties in this, it is expensive, and may conflict with Custom and Excise regulations. Further, the increase in puff number is insufficient to compensate for the decrease in puff number caused by a filler or decreased intrinsic density.

We have found in the present invention that the decrease in puff number may be at least partly compensated for by a method which does not suffer from disadvantages associated with the methods listed above. 45366 - 5 According to the present invention there is provided an elongate smoking article such as a cigarette, cigar or cigarillo comprising the combination of a highnicotine filler for the smoking article containing at least a proportion of expanded tobacco and means for ventilating the smoking article, whereby the ratio of particulate material yield of the smoke to nicotine yield of the smoke is reduced and the puff number of the article is substantially not lessened compared with an unventilated article containing no expanded tobacco.

Thus it is possible by ventilating cigarettes, cigarillos or cigars which contain expanded tobacco as a low density filler to compensate wholly or in part for the reduction in the puff number produced by the inclusion of low density filler.

The expanded tobacco filler may be prepared by any puffing technique so that the bulk volume of the material is increased. Known techniques include impregnation of the material with specific liquids, solutions or gases arid subsequent treatment involving heat or microwave energy used alone or in combination with use of airpressure changes so as to cause expansion of the material.

Impregnation of the material with specific liquids is discussed for example in U.S. patent specifications 3524451 and 3524452.

One particular technique of producing low density filler material from the natural product is freeze-drying. Improvements in filling power of 46-63% have been achieved with cut tobacco lamina and comparable Improvements have been achieved .'by this technique on flue cured cut rolled tobacco stem. Improvements have been achieved with cigar fillers, including single grades and blends of threshed lamina.

To demonstrate the reduction of puff number resulting from the use of low density filler materials, 45Q6C - 6 four class B cigarettes, 71 mm long were made up using a traditional flue cured cigarette tobacco filler but having increasing percentages of freeze dried cut tobacco lamina of 48/49% filling power improvement blended with it. A class B cigarette is defined as a cigarette 71 mm long and 25 mm in circumference. The cigarettes were weighed and smoked on a Cigarette Components Limited Filtrona 300 I 20 channel restricted smoking machine at the rate of one 2 second 35 ml puff per minute on each channel independently. Restricted means that, during the smoking test, the unlit ends of the cigarettes are not open to atmosphere between puffs. Filtrona is a Registered Trade Mark.

Further details of the technique of smoking cigarettes on a smoking machine are to be found in Research Paper 11, (2nd edition) Standard methods for the analysis of tobacco smoke, published by the Tobacco Research Council, London 1974.

The number of puffs needed to consume each cigarette to a standard length stub portion is shown in Table 1.

Table 1 Freeze-dried cut lamina in blend(%) Mean cigarette weight (mg) Puffs/cigarette 0 (Control) 819 11.0 20 702 9.4 50 600 8.2 100 485 6.3 It will be seen that from 11 puffs per cigarette with normal filler, only 6.3 puffs were required with a filler wholly made from lower density higher filling value material.

The ventilation of cigarettes may be achieved 8 6 6 - 7 by the use of papers of high inherent porosity or of paper perforated randomly or in patterns, or by the use of perforated or permeable tipping materials and filter components whereby ambient air is introduced into the smoke stream and/or into the smokers mouth.

The use of covering materials of high inherent porosity may increase the rate of burn by allowing freer access of air through the covering during the smouldering or non-puffing phases of smoking.

These materials are therefore less useful for achieving the object of the invention, but need not be excluded as they may also be perforated to still higher porosity.

The ventilation of the covering material by perforation may be effected before or after manufacture of the smoking article. Cigarette papers are ventilated before manufacture of the cigarettes, while cigars are perforated after application of the binder and wrapper.

To demonstrate the increase in puff number afforded by the use of perforated cigarette paper four class B 71 mm cigarettes were made up using the same paper and the same traditional flue cured tobacco filler, and the paper wrappers were perforated to differing extends to provide variation in ventilation. The cigarettes were smoked on the aforesaid smoking machine and the number of puffs required to smoke each cigarette was recorded. The results are listed in Table 2. paper permeability 2 mls/min/cm /cm w.g. Table 2 Puff number %increase in puff no. over control 0.9 (Control) 10.2 - 6.7 10.9 7 17.7 11.6 14 22.9 11.9 17 8 6 6 - 8 To demonstrate the increase in puff number afforded by the use of ventilated filters on cigarettes four 84 mm class B filter cigarettes were made up containing a typical flue-cured tobacco blend. Each had an Acetate plug with Malaucene No.3 plugwrap. The cigarettes were perforated at the filter plugs to differing degrees to provide a variation in the air dilution at the filter and the cigarettes were smoked on the aforesaid smoking machine to determine the number of puffs required to consume them. The results are listed in Table 3.

Table 3 % tip dilution Puff number %increase in puff no. over control 0 11.1 - 37 12.1 9 50 12.8 15 62 13.2 19 To demonstrate the increase in puff number afforded by the perforation of cigar binder and wrapper after their application to the cigar four samples of three sizes of cigars were perforated manually using blocks of 0.25 mm diameter needles to provide a variety of perforations ranging from zero perforations (control) to 40 perforations. The cigars were smoked on the aforesaid smoking machine to determine the number of puffs needed to consume each one.

The results are given in Table 4. - 9 Table 4 Minature cigar Small cigar Large cigar puff no. % increase puff over control no. %increase over control puff no· o % increase ver control 0 holes (control) 10.3 - 23.5 - 39.1 - 6 holes 10.9 6 24.9 6 39.1 0 20 holes 11.6 13 27.4 17 42.4 8 40 holes 12.6 22 29.3 25 42.9 10 Thus from Table 1 it will be seen that increasing quantities of lower density higher filling value filler reduces the number of puffs needed to smoke the ι cigarettes whereas increasing the permeability of cigarette paper. (Table 2) or increasing the ventilation of a cigarette filter (Table 3) or increasing the perforations of cigar wrapper (Table 4) has the effect of increasing the number of puffs needed to smoke the article.

To demonstrate how ventilation may be used to compensate wholly or at least in part for the reduction in the number of puffs required to smoke cigarettes containing expanded low density filler, a number of king-size cigarettes having various levels of ventilation and containing various proportions of expanded flue-cured tobacco filler were made, weighted and smoked on the aforesaid smoking machine. The number of puffs needed to consume the cigarettes to a standard length stub is shown in Table 5. - 10 45800 Table 5 Expanded Cut Lamina in Blend *Cigarette Ventilation Mean Cigarette Weight (mg) Puff No. 0vo 1148 12.8 5 Vo 12.2 1109V1 13.3 10vo 12.3V2 1096 14.1 v3 14.6 20 vn 11.5 1046V4 15.7 100Vo 8.5V1 783 9.2V2 10.1 ’3 10.4 CIGARETTE PAPER CIGARETTE FILTER TOTAL AIR PERMEABILITY MAINSTREAM MAINSTREAM MAINSTREAM ml/min/om / cm HgO AIR DILUTION AIR DILUTION AIR DILUTION % Of 35 ml puff % Of 35 ml Puff %of 35 ml puff * Vo 1.1 5 1 6V1 8.8 I 29 1 30V2 19.0 43 1 44V3 1.1 5 37 42 8.8 29 37 66 5866 -lilt will be seen that from 12.8 puffs per cigarette with normal (unexpended) tobacco filler and ventilation VQ, only 8.5 puffs were required to consume the cigarette containing filler made wholly from expanded tobacco and ventilation Vo. For blends containing only part expended tobacco the reduction in cigarette puff number is proportionately less.

On varying the ventilation of the cigarette paper and filter (V]_ to V^) it will be seen that this decrease in the cigarette puff number can be wholly or at least partly compensated.

To demonstrate how the combination of highnicotine expended tobacco and ventilated cigarette paper maintains the cigarette puff number at an acceptable level but lowers the tar: nicotine ratio in the smoke, class B cigarettes made with various levels of ventilation and containing various proportions of expanded flue-cured tobacco, were smoked to a standard length stub on the aforesaid «smoking machine, and the smoke analysed for particulate material (PM, that is tar), and nicotine. The results are shown in Table 6.

The last column in Table 6 shows the percentage decrease in the smoke PM/Nicotine ratio compared with that of an unventilated cigarette containing no expanded cut tobacco. It will be seen that this percentage increases in accordance with the amount of expanded cut tobacco in the blend.

Further ventilation, resulting in a more complete compensation of cigarette puff number and lower tar yield, is of course possible. Hence it is possible, by combining expanded high-nicotine tobacco filler with ventilated cigarette coverings or filters, to provide low tar cigarettes having a higher than presently obtainable yield of nicotine without the disadvantages of ventilated cigarettes containing normal high-nicotine tobacco or of 45836 - 12 unventilated cigarettes containing expanded tobacco.

A further advantage of the combination of expanded tobacco and ventilated cigarette paper is that smoke caibcm ncnoxide yield can be reduced further than is possible with ventilated cigarettes containing normal tobacco. To demonstrate this, class B cigarettes were made containing various proportions of expanded cut lamina in the filler and having various degrees of venti lation. These cigarettes were smoked to a standard stub o •H 4686C 1 G 1 4J w •rl 0 rt ϋ ϋ ft fl) ·Η Q W S fl) rt \ tf dP Φ 2 •rH ft P O to M L£> rH CO ι—1 CM CM Expanded Cut * Mean Filler PM (wnf) Nicotine PM(wnf) Lamina in Cigarette Cigarette Nicotine Puff Yield Yield Nicotine Blend (%) Ventilation Weight (mg) Content % Number (mg/ctte) (mg/ctte) Ratio O cm vo σ\ h cn co rCM CM Γ·» \O rH ι—I rH CM Γ- CO rH i-l a o •rl 4J G r—1 •rl Q W •rH tw t|H tf ft o o ‘θ LO »—1 r-1 LO LO tT tp rH rH tp cn to rH • • • CM CM r—1 o rH rH i—1 rH Paper Γ” CO to CO 0) •M* r* CM o • • • +J CM CM CO n* 4J 0) OO to tp tf Η O r-l rd CM CM CM OO cn r* CM CM CM > > > > μ rt tn Ή U £ rt CD w •P ω G •rl rt £ LO CO tw dP co >1 +) •rl «—1 •rl XJ rt u Φ \ £ cm M £ O CM ft ϋ •rt .6 < \ rH rH O rH Ot rH CM > 'wnf means water and nicotine free 8 6 6 - 14 length on an eight channel Cigarette Components Limited 301 smoking machine, and the carbon monoxide content of the smoke measured. The results are shown in Table 7.

Table 7 Expanded Cut ♦Cigarette Mean Cigarette Puff Smoke Carbon Lamina in Ventilation Weight No. Monoxide Yield Blend (%) (mg) (mg/ctte) 0vo 1148 12.4 19.4V2 14.6 14.9 20 vo 11.8 17.4 1046V2 12.9 12.9 100 vo 8.4 11.9 782V2 10.1 10.0 AIR PERMEABILITY CIGARETTE PAPER MAINSTREAM AIR DILUTION 2 1 ml/min/cm /can HgO % of 35 ml puff *V 1.1 o 5 V2 19.0 43 It will be seen from the data in Table 7 that a significant reduction in carbon monoxide yield can be achieved without any significant alteration to the cigarette puff number.

Although described with reference to cigarettes and cigars the invention may be applied to cigarillos and other similar smoking articles. The invention may be applied to tobaccos that have been expanded by means other than freeze-drying, such as impregnating the tobacco with an evaporable liquid. 458GG - 15 By ventilating cigarettes, cigars or cigarillos to increase the ambient air in the smoke stream or reaching the mouth of the smokers it is possible to compensate wholly or at least in part for the reduction in the number of puffs needed to smoke the produce, to reduce the carbon monoxide yield in the smoke, and to produce a smoking article utilizing expanded tobacco and having a low tar: nicotine ratio without reducing the puff number.

Claims (5)

1. 'l. An elongate smoking article such as a cigarette, cigar or cigarillo comprising the combination of a high-nicotine filler for the smoking article 5 containing at least a proportion of expanded tobacco and means for ventilating the smoking article, whereby the ratio of particulate material yield of the smoke to nicotine yield of the smoke is reduced and the puff number of the article is substantially not lessened 10 compared with an unventilated article containing no expanded tobacco.

2. An elongate smoking article as claimed in claim 1 wherein the expanded tobacco comprises at least 20% by weight of the total filler. 15

3. An elongate smoking article as claimed in claim 1 oa; 2 wherein the nicotine content of the filler is at least 2.73% by weight.

4. An elongate smoking article as claimed in any preceding claim wherein the air permeability of the 2 20 means for ventilating is at least 19.0 ml/min/cm /cm HgO. '5. ’An elongate smoking article as claimed in any preceding claim wherein the means for ventilating is provided by a perforated filter plug. 6. An elongate smoking article as claimed in 25 any preceding claim wherein the means for ventilating is provided by a.region of perforations and/or a region of high porosity in the outer covering of the article. 7. An elongate smoking article as claimed in claim 6 wherein the outer covering is paper and the 30 article is a cigarette. - 17 8. An elongate smoking article as claimed in any preceding claim wherein the expanded tobacco is selected from the group consisting of tobacco stem, threshed lamina strips, cut lamina, scrap and shorts.

5. 9. An elongate smoking article as claimed in claim 1 as hereinbefore described with reference to Tables 5, 6 and 7.