WO1993002575A1 - Control of cigarette smoke chemistry - Google Patents
Control of cigarette smoke chemistry Download PDFInfo
- Publication number
- WO1993002575A1 WO1993002575A1 PCT/CA1992/000344 CA9200344W WO9302575A1 WO 1993002575 A1 WO1993002575 A1 WO 1993002575A1 CA 9200344 W CA9200344 W CA 9200344W WO 9302575 A1 WO9302575 A1 WO 9302575A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cigarette
- tobacco
- smoke
- filter element
- cylinder
- Prior art date
Links
Classifications
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- A24D1/00—Cigars; Cigarettes
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- A24D3/00—Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes
- A24D3/04—Tobacco smoke filters characterised by their shape or structure
Definitions
- the present invention relates to controlling the chemistry of cigarette smoke entering a smoker's mouth, to provide a desirable combination of high sensory appeal and low tar.
- BACKGROUND TO THE INVENTION Tar is a component of cigarette smoke considered undesirable and attempts are continually being made to deliver lower guantities of tar to the smoker.
- Conventional procedures have included increased filtration and ventilation. However, only a certain level of filtration can be achieved with conventional filters before the pressure drop across the filter becomes unacceptably high.
- the present invention achieves a unique result, in providing the high flavour level associated with popular brands of cigarettes but at a significantly lower tar level.
- a cigarette in accordance with the invention may be provided which delivers 6.7 mg of tar while providing the flavour of a conventional 14.0 mg tar cigarette.
- the present invention is able to provide a more uniform delivery of flavour and tar as the cigarette is smoked, as compared with a conventional cigarette.
- a novel cigarette which comprises a tobacco filler rod comprising a higher-than- normal proportion of tobacco derived from leaves from the upper levels of tobacco plants, such as to provide a higher flavour-to-tar ratio in the smoke produced upon smoking the cigarette rod; a tobacco smoke filter element through which tobacco smoke passes from the burning tobacco filler rod upon smoking of the cigarette and contructed to attenuate the flavour level of smoke delivered to the smoker, while maintaining approximately the same flavour-to-tar ratio; and means associated with at least one of the filler rod and filter element for decreasing the level of both flavour and tar in the cigarette smoke during later stages of smoking of the filler rod.
- Figure 1 is a bar graph presentation of smoking test results
- Figure 2 is a graphical presentation of additional smoking test results
- Figure 3 is a graphical presentation of additional smoking test results.
- flavour produced by tobacco from such leaves, or the tips generally is too high to be acceptable to a smoker in a conventional cigarette and hence the tobacco usually is blended with tobacco from the whole plant to provide an overall lower flavoured tobacco blend.
- the applicants have found that it is possible to employ such strongly flavoured tobacco and not only achieve a flavour level comparable to that of popular brands, but thereby deliver a much lower level of tar, consistent with the higher flavour/tar ratio of smoke produced by such tobacco.
- a higher flavour level may be provided but at a lower or the same tar level, as required.
- microfine fibers in tubular form to achieve high levels of filtration.
- Such microfine fibers may be used herein to decrease the flavour level produced by the tobacco.
- the microfine fibers in the cylinder thereof generally each has a diameter of about 0.5 to 10 microns.
- the cylinder of such fibers generally has a thickness of about 0.05 to about 4 mm and a density of about 0.05 to about 0.3 g/cc.
- the elongate cylinder of microfine fibers preferably is arranged so that all the tobacco smoke passing through the filter containing the microfine fibers cylinder is directed through the cylinder wall.
- This result may be achieved by providing an outer annulus of high density conventional acetate filter tow material surrounding the microfine fiber cylinder, which in turn surrounds an inner core.
- a baffle, or other tobacco flow path directing means, is provided at the upstream end to direct tobacco smoke from the cigarette only into the high density material.
- the microfine fiber cylinder is a highly efficient filtration medium but rapidly becomes clogged, so that the tobacco smoke must traverse an increasingly longer path through the outer annulus of conventional tow material and is filtered thereby before passing through the wall of the cylinder of microfine fibers into an inner axial cigarette smoke flow path leading to the downstream end of the filter element.
- the filter achieves a greater degree of filtration of the tobacco smoke as smoking proceeds and hence tends to counteract the increasing level of flavour and tar delivery which results as smoking progresses, so that a more uniform flavour delivery to the smoker is achieved.
- the axial tobacco flow path provided radially inwardly of the cylinder of microfine fibers may be filled with low flow resistance acetate material, which may be crimped against tobacco smoke flow at the upstream end.
- tobacco flow into the axial flow path may be presented by crimping of the upstream end of the cylinder of microfine fibers.
- the axial cigarette smoke path radially inwardly of the elongate cylinder of microfine fibers may be provided by an elongate plastic tube having a star-shaped cross section, so as to define a plurality of flow paths radially inwardly of the cylinder of microfine fibers through which cigarette smoke may flow longitudinally of cigarette.
- the effect of the filtration efficiency between the first and last puffs of smoke can be increased further by providing an opening or openings through the cylinder of microfine fibers at or adjacent the upstream end thereof extending between the outer annulus of conventional tow material and the axial flow path, so that a substantial portion of the first puff of cigarette smoke travels only a short distance through the high efficiency tow and then enters the axial flow path preferentially through the openings, thereby by-passing travel through the microfine fibers.
- the access of the smoke to these openings is diminished as the cigarette is smoked, due to the collection of tar in the high efficiency tow adjacent the openings.
- a cigarette smoke filter element which comprises an outer elongate cylinder of tobacco smoke filter material; an inner elongate cylinder of microfine fibers; an axial cigarette smoke path located radially inwardly of the cylinder of microfine fibers; the outer cylinder of smoke filter material having a greater resistance to the flow of cigarette smoke therethrough than the axial flow path; the cylinder having at least one opening therethrough adjacent the upstream end of the filter element to permit preferential passage of cigarette smoke from the outer cylinder through the at least one opening to the axial flow path during initial smoking of a cigarette to which the filter element is attached; and tobacco smoke flow path directing means located at the upstream end of the filter element in the intended direction of flow of cigarette smoke thereto for directing cigarette smoke from a
- the conventional high density tow material may be provided at the core of the filter element, with the low density tow or no tow at all being provided as the outer annulus.
- a baffle or other smoke path directing means again is provided to direct smoke, this time into the central core.
- the present invention in a further aspect, provides a cigarette smoke filter element, comprising an elongate plug of tobacco smoke filter material; an elongate cylinder of non-absorbent microfine fibers provided on the elongate plug and having a lesser resistance to the flow of cigarette smoke radially therethrough than longitudinally through the elongate plug; an axially-directed annular tobacco smoke flow path located radially outwardly of the elongate cylinder having a lesser resistance to the flow of cigarette smoke longitudinally therein than longitudinally through the elongate plug; and tobacco smoke flow path directing means located at the upstream end of the filter element in the intended direction of flow of cigarette smoke thereto for directing cigarette smoke from a cigarette to which the filter element is attached only into the elongate plug of tobacco filter material.
- ventilation holes may be provided in the filter wrapper closer to downstream end of the filter than is normal to improve CO dispersion of carbon monoxide (CO) .
- CO carbon monoxide
- ventilation decreases the CO content of the smoke entering the smoker's mouth.
- the higher-than-normal flavour/tar ratio tobacco which is used herein produces a higher-than-normal flavour level in the tobacco smoke from a burning cigarette containing the same.
- the flavour level of tobacco reaching the smoker's mouth from the burning cigarette is decreased to conventional levels.
- this same ratio may be retained when the smoke reaches the smoker's mouth, so that a significantly lower tar delivery results while the same flavour level is achieved as in a conventional highly- flavoured brand of cigarette.
- the uniformity of delivery of the tobacco flavour to the smoker from a cigarette can be improved further by providing a greater proportion of more highly-flavoured tobacco towards the lighting end and a greater proportion of less highly-flavoured tobacco towards the filter end of the cigarette.
- the flavour strength produced by a cigarette increases as smoking progresses.
- this effect tends to be counteracted.
- a filler rod containing a combination of differently-flavoured tobacco may be provided in the manner described in U.S. Patent No. 4,896,681, assigned to one of the assignees hereof and the disclosure of which is incorporated herein by reference.
- discrete segments ofdifferently-flavoured tobacco may be employed in the filler rod.
- the present invention therefore, provides a cigarette which exhibits a high sensory appeal while delivering a low. level of tar to the smoker with a more uniform flavour delivery, by a combination of factors, as follows:
- flavour strength reset to attenuate the flavour strength of the smoke to the level desired by the smoker.
- the latter puff anipulatioh with respect to the flavour and tar produced in the latter puffs of smoking the cigarette may be effected, as described above, by utilizing a smoke re-route filtration technique or by using lesser strength tobacco at the filter end, or preferably both.
- Flavour strength reset is achieved, as described above, by utilizing a cylinder of microfine fibers as a filter element, or by using lesser strength tobacco at the filter end or preferably by using expanded tobacco at the filter end, or preferably a combination thereof.
- the cylinder of microfine fibers being incorporated into a smoke re-route filter and a higher proportion of lesser-flavoured expanded tobacco being used at the filter end and a higher proportion of the higher-than- normal flavour tobacco, possessing the high flavour-to- tar ratio, being used at the lighting end.
- Example 1 A blind smoking test was carried out, wherein a cigarette constructed in accordance with the principles of the present invention was smoked and compared to a standard popular cigarette brand in Canada (Benson & Hedges 100s) .
- the cigarette of the invention was perceived to be flavourful, higher in impact and effects, yielding a better-balanced, fuller and smoother smoke in the early puffs. Very little change was observed in the flavour, impact, irritation and flavour balance in the latter half of the cigarette.
- the cigarette of the invention was preferred generally over the standard brand.
- Example 2 A blind smoking test was carried out, wherein a cigarette constructed in accordance with the principles of the present invention was smoked and compared to a standard popular cigarette brand in Canada (Benson & Hedges 100s) .
- the cigarette of the invention was perceived to be flavourful, higher in impact and effects, yielding a better-balanced, fuller and smoother smoke in the early puffs. Very little change was observed in the flavour, impact, irritation
- Smoking tests were carried out on the cigarette samples which were the subject of the smoking test in Example 1. Determinations were carried out for total tar, nicotine and CO at the same flavour strength.
- the standard Benson & Hedges 100s (B & H) cigarettes increased from an initial tar level of 0.5 mg to a last puff tar level of 1.8 mg for a total of 13.1 mg.
- the highly flavoured tobacco was provided as a segment at the lighting end of the cigarette and a segment of expanded tobacco was provided at the filter end. Again a standard B fit H filter was used. Plot (4) was obtained for this cigarette.
- plot (2) shown an increase from 0.3 to 1.7 mg during smoking for a total tar deliveries of 10.1 mg, i.e. significantly below the B & H value.
- a comparison of plots (2) and (5) illustrates the significant effect that the replacement of the conventional filter by one containing a cylinder of microfine fibers has on the tar delivery.
- plot (1) there is shown the tar delivery from a cigarette having a filter containing a cylinder of microfine fibers and containing a segment of expanded tobacco at the filter end. The tar increased from 0.2 mg for the first puff to 0.9 mg at the last puff, for a total tar delivery of only 4.7 mg.
- a comparison of plots (1) and (4) illustrates the effect on tar delivery of the utilization of a filter comprising a cylinder of microfine fibers in place of a conventional filter.
- a comparison of plots (1) and (3) illustrates the effect on the tar delivery of the utilization of a cigarette constructed according to the present invention in comparison to a standard cigarette delivering the same flavour level. It will also be seen that, not only is a lower puff-to-puff level of tar delivery and an overall significantly lower tar delivery achieved, but the curve is flatter in the case of the present invention, so that a more uniform delivery of tar and flavour is achieved.
- Example 4 Smoking tests were carried out to explore the effect of further manipulation of a cigarette. The tar/puff values were plotted against puff number. The results obtained are plotted graphically in Figure 3.
- Plots (1) and (3) compare the results obtained with an 84 mm Rothmans King Size ("RKS") cigarette as manufactured in Canada delivering a total of 16 mg of tar with a cigarette using a highly flavoured blend and a filter containing a cylinder of microfine fibers with openings through the cylinder at the upstream end (plot 2) .
- a comparison of plot (1) with plot (3) shows that not only is a lower puff-to-puff level of tar delivery and an overall significantly lower tar delivery achieved, but the curve is flatter in the case of the present invention, so that a more uniform delivery of tar and flavour is achieved.
- plots (1) and (3) of Figure 2 are repeated in Figure 3 as plots (4) and (3) respectively.
- the present invention provides a novel cigarette construction which enables a full flavour smoke to be provided at a significantly decreased tar level. Modifications are possible within the scope of this invention.
Landscapes
- Cigarettes, Filters, And Manufacturing Of Filters (AREA)
- Indole Compounds (AREA)
- Manufacture Of Tobacco Products (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5503145A JPH07503603A (en) | 1991-08-08 | 1992-08-07 | Control of cigarette smoke chemistry |
DE69229635T DE69229635T2 (en) | 1991-08-08 | 1992-08-07 | CHEMICAL CONTROL OF TOBACCO SMOKING |
AU24176/92A AU668876B2 (en) | 1991-08-08 | 1992-08-07 | Control of cigarette smoke chemistry |
CA002114128A CA2114128C (en) | 1991-08-08 | 1992-08-07 | Control of cigarette smoke chemistry |
EP92916991A EP0599897B1 (en) | 1991-08-08 | 1992-08-07 | Control of cigarette smoke chemistry |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9117118.1 | 1991-08-08 | ||
GB919117118A GB9117118D0 (en) | 1991-08-08 | 1991-08-08 | Control of cigarette smoke chemistry |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993002575A1 true WO1993002575A1 (en) | 1993-02-18 |
Family
ID=10699690
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CA1992/000344 WO1993002575A1 (en) | 1991-08-08 | 1992-08-07 | Control of cigarette smoke chemistry |
Country Status (9)
Country | Link |
---|---|
EP (1) | EP0599897B1 (en) |
JP (1) | JPH07503603A (en) |
AT (1) | ATE182249T1 (en) |
AU (1) | AU668876B2 (en) |
CA (1) | CA2114128C (en) |
DE (1) | DE69229635T2 (en) |
GB (1) | GB9117118D0 (en) |
WO (1) | WO1993002575A1 (en) |
ZA (1) | ZA925956B (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0226368A2 (en) * | 1985-12-04 | 1987-06-24 | Rothmans, Benson & Hedges Inc. | Sculptured cigarette |
EP0364253A1 (en) * | 1988-10-12 | 1990-04-18 | Rothmans International Services Limited | Cigarette filter rod elements and cigarettes incorporating such filter rod elements |
WO1990009741A1 (en) * | 1989-03-02 | 1990-09-07 | Rothmans, Benson & Hedges Inc. | Uniform tar delivery profile filter |
EP0408354A2 (en) * | 1989-07-14 | 1991-01-16 | Rothmans International Services Limited | Cigarettes |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB9008887D0 (en) * | 1990-04-20 | 1990-06-20 | Rothmans Benson & Hedges | Cigarette smoke filter |
-
1991
- 1991-08-08 GB GB919117118A patent/GB9117118D0/en active Pending
-
1992
- 1992-08-07 JP JP5503145A patent/JPH07503603A/en active Pending
- 1992-08-07 AT AT92916991T patent/ATE182249T1/en not_active IP Right Cessation
- 1992-08-07 ZA ZA925956A patent/ZA925956B/en unknown
- 1992-08-07 CA CA002114128A patent/CA2114128C/en not_active Expired - Fee Related
- 1992-08-07 DE DE69229635T patent/DE69229635T2/en not_active Expired - Fee Related
- 1992-08-07 WO PCT/CA1992/000344 patent/WO1993002575A1/en active IP Right Grant
- 1992-08-07 AU AU24176/92A patent/AU668876B2/en not_active Ceased
- 1992-08-07 EP EP92916991A patent/EP0599897B1/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0226368A2 (en) * | 1985-12-04 | 1987-06-24 | Rothmans, Benson & Hedges Inc. | Sculptured cigarette |
EP0364253A1 (en) * | 1988-10-12 | 1990-04-18 | Rothmans International Services Limited | Cigarette filter rod elements and cigarettes incorporating such filter rod elements |
WO1990009741A1 (en) * | 1989-03-02 | 1990-09-07 | Rothmans, Benson & Hedges Inc. | Uniform tar delivery profile filter |
EP0408354A2 (en) * | 1989-07-14 | 1991-01-16 | Rothmans International Services Limited | Cigarettes |
Also Published As
Publication number | Publication date |
---|---|
DE69229635T2 (en) | 2000-03-16 |
AU2417692A (en) | 1993-03-02 |
JPH07503603A (en) | 1995-04-20 |
ZA925956B (en) | 1993-04-28 |
DE69229635D1 (en) | 1999-08-26 |
AU668876B2 (en) | 1996-05-23 |
EP0599897B1 (en) | 1999-07-21 |
CA2114128A1 (en) | 1993-02-18 |
CA2114128C (en) | 1999-10-12 |
EP0599897A1 (en) | 1994-06-08 |
GB9117118D0 (en) | 1991-09-25 |
ATE182249T1 (en) | 1999-08-15 |
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