CIGARETTE
United States Patent 3699972
A cigarette is described which has the wrapper treated with a burn accelerating agent over a preselected area. An aperture is formed in this area. The burn accelerating agent causes the treated area of the wrapper to burn more rapidly than the untreated surrounding area so that an increased flow of air is caused to enter through the rapid burn area ahead of the burning coal during smoking. The air entering through the rapid burn area, in combination with the air entering through the aperture, dilutes the smoke stream and substantially reduces the delivery of smoke constituents. The provision of a slit through the treated area provides for a constant flow of air through the wrapper, during puffing of the cigarette, thus causing some dilution of the smoke stream at all times.
US Patent References:
Cigarette
Fay et al. - May 1958 - 2836183
Smoking article
Trane - January 1942 - 2269995
Thermostatically controlled cigarette and method of making the same
Figge - July 1961 - 2992647
Cigarette
Fay et al. - May 1958 - 2836183
Smoking article
Trane - January 1942 - 2269995
Thermostatically controlled cigarette and method of making the same
Figge - July 1961 - 2992647
Application Number:
05/068163
Publication Date:
10/24/1972
Filing Date:
08/31/1970
View Patent Images:
Export Citation:
Assignee:
Brown & Williamson Tobacco Corporation (Louisville, KY)
Primary Class:
International Classes:
A24D1/02; A24D1/00
Field of Search:
131/8,9,15C,15B,15R,1A,198
Primary Examiner:
Koren, Samuel
Assistant Examiner:
Yahwak G. M.
Claims:
What is claimed is
1. In a cigarette of the type having a wrapper containing tobacco, a first end adapted as a mouthpiece for the smoker and a second end adapted to be lighted, the improvement in combination therewith comprising:
2. A cigarette in accordance with claim 1 wherein the potassium nitrate is applied to the wrapper in a triangular pattern with the base of the triangle closer to the mouthpiece end of the cigarette.
3. A cigarette in accordance with claim 2 wherein the apex of the triangle is positioned at a point short of the end to be lighted.
4. A cigarette in accordance with claim 3 wherein the apex of the triangle is at a point about one-third the length of the cigarette from the mouthpiece.
5. A cigarette in accordance with claim 1 wherein the potassium nitrate is applied to the wrapper as an elongated strip extending from the mouthpiece end of the cigarette.
6. A cigarette in accordance with claim 5 wherein the aperture includes a slit.
7. A cigarette in accordance with claim 4 wherein slits extend longitudinally along the wrapper.
8. A cigarette in accordance with claim 5 wherein the elongated strip extends at least one-third the length of the cigarette from the mouthpiece.
9. A process of treating a cigarette to reduce the delivery of smoke constituents including the steps of applying potassium nitrate to preselected areas of the cigarette wrapper, and thereafter aperturing the wrapper in these areas.
10. A process in accordance with claim 9 wherein the potassium nitrate is applied from an aqueous solution.
11. A process in accordance with claim 10 wherein the aqueous solution contains about 30 percent by weight potassium nitrate.
1. In a cigarette of the type having a wrapper containing tobacco, a first end adapted as a mouthpiece for the smoker and a second end adapted to be lighted, the improvement in combination therewith comprising:
2. A cigarette in accordance with claim 1 wherein the potassium nitrate is applied to the wrapper in a triangular pattern with the base of the triangle closer to the mouthpiece end of the cigarette.
3. A cigarette in accordance with claim 2 wherein the apex of the triangle is positioned at a point short of the end to be lighted.
4. A cigarette in accordance with claim 3 wherein the apex of the triangle is at a point about one-third the length of the cigarette from the mouthpiece.
5. A cigarette in accordance with claim 1 wherein the potassium nitrate is applied to the wrapper as an elongated strip extending from the mouthpiece end of the cigarette.
6. A cigarette in accordance with claim 5 wherein the aperture includes a slit.
7. A cigarette in accordance with claim 4 wherein slits extend longitudinally along the wrapper.
8. A cigarette in accordance with claim 5 wherein the elongated strip extends at least one-third the length of the cigarette from the mouthpiece.
9. A process of treating a cigarette to reduce the delivery of smoke constituents including the steps of applying potassium nitrate to preselected areas of the cigarette wrapper, and thereafter aperturing the wrapper in these areas.
10. A process in accordance with claim 9 wherein the potassium nitrate is applied from an aqueous solution.
11. A process in accordance with claim 10 wherein the aqueous solution contains about 30 percent by weight potassium nitrate.
Description:
BACKGROUND OF THE INVENTION
This invention relates to an improved cigarette having means for reducing the delivery of smoke constituents.
Much effort in the field of cigarette research is directed to the problem of eliminating or reducing products contained in cigarette smoke. One approach to this problem has been the use of holes in the cigarette which permit air to enter the smoke stream as the cigarette is smoked to dilute the smoke with air. Another approach is to place a sealant over circumferentially spaced holes in the cigarette. The sealant vaporizes as the burning coal approaches to permit air to enter the smoke stream through the hole and prevent the combustion temperature from exceeding a predetermined limit. These and other approaches to the problem have reduced somewhat the products contained in the cigarette smoke but not to a level sufficient to substantially reduce the tar delivered with the smoke to a desired level.
BRIEF SUMMARY
A cigarette has now been developed which substantially reduces the delivery of smoke constituents by means of air dilution of the smoke stream.
An object of this invention therefore is to provide an improved cigarette which substantially reduces the delivery of tar and other smoke products.
Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a side elevation view of a cigarette treated with a burn accelerating agent applied to the wrapper over triangular-shaped, perforated areas;
FIG. 2 is a side elevation view of a cigarette treated with a burn accelerating agent applied to the wrapper as a perforated strip;
FIG. 3 is a close-up view of the perforations and treated area of FIG. 2;
FIG. 4 is a fragmentary sectional view taken along the line 4--4 of FIG. 3;
FIG. 5 is a side elevation view of a cigarette treated with a burn accelerating agent applied as a strip which is provided with a series of slits extending longitudinally along the cigarette from the mouthpiece;
FIG. 6 is a vertical sectional view taken along the line 6--6 of FIG. 5; and
FIG. 7 is a side elevation view of a cigarette treated with a burn accelerating agent applied to the wrapper over triangular-shaped, perforated areas, the areas extending about one-third the length of the cigarette from the mouthpiece.
In accordance with this invention a burn accelerating agent is applied to preselected areas of a cigarette wrapper to accelerate the burn rate of the wrapper. These treated areas are provided with an aperture which extends through the coating or agent residue on the surface and the wrapper. When the cigarette is smoked, the treated areas of the cigarette wrapper burn more rapidly to permit air to enter the smoke stream at a point ahead of the burning coal which, in combination with the air entering through the aperture, substantially reduces the delivery of tar and other constituents in the smoke. Because of the aperture, some air is passed through the wrapper with each puff. It is believed that passage of air through the aperture causes the portion of the wrapper surrounding the aperture to be raised from the tobacco column and thus causes more rapid burning when the burning coal reaches the area.
PREFERRED EMBODIMENTS
FIG. 1 shows cigarette 10 having mouthpiece 11 and a burn rate accelerating agent applied to wrapper 20 in a plurality of triangular-shaped treated areas 12, 13 and 14 extending from the mouthpiece to a point somewhat short of the end to be lighted 25. Although treated areas 12, 13 and 14 are perforated, FIG. 1 only shows treated area 13 having perforations 15 distributed substantially over its entire length. As cigarette 10 is smoked, the burning coal of the lighted end approaches the apex end of triangular-shaped areas 12, 13 and 14. The burn agent will then promote accelerated burning of the treated areas of cigarette wrapper 20 to permit an influx of air into the tobacco smoke stream at a point ahead of the burning coal. The treated areas get progressively larger toward mouthpiece end 11 of cigarette 10 due to the triangular pattern to permit a larger volume of air to enter the smoke stream as the cigarette is smoked closer to mouthpiece end 11. The dilution effect substantially reduces the tar delivery which increases considerably as the cigarette is smoked. Perforations 15 extend through the residue or coating of the burn agent of area 13 and wrapper 20 to the tobacco beneath. The combined effect therefore is to have air dilution in the smoke stream coming from the perforations 15 and the accelerated burn area 13 of wrapper 20.
FIG. 2 shows cigarette 10 provided with a treated area or strip of burn promoting agent 16 applied to wrapper 20 and extending from mouthpiece end 11 toward the end to be lighted 25. Since the air dilution effect on the tar and other products in the smoke is minimized close to cigarette end 25, strip 16 extends to a point somewhat short of end 25. Treated area 16 is provided with perforations 17 to allow air intake. FIG. 3 is a close-up view of treated area 16 and perforations 17. As shown in FIG. 3, tobacco 18 is exposed to the atmosphere by means of perforation 17 which extends through the residue or coating of treated area 16 and wrapper 20. In this connection, FIG. 4 shows perforation 17 extending completely through treated area 16 and wrapper 20 to expose tobacco 18 beneath. It should be noted that treated area 16 is shown in FIG. 4 as a separate layer. Such a showing is intended to be schematic and in actual application of this invention the burn promoting agent may be absorbed by wrapper 20 and leave no residue, coating or layer as shown in FIG. 4. The perforations shown in FIGS. 1 through 4 should be at least 0.5 millimeters in diameter.
FIG. 5 shows an additional embodiment of this invention in which a treated area 21 extends longitudinally along the cigarette from mouthpiece end 11 toward end 25. Cigarette 10 is provided with a plurality of slits 22 extending longitudinally along wrapper 20. As the burning coal progressively reaches each of slits 22, the area surrounding the slit is opened to admit additional air. Slits 22 extend through treated area 21 and wrapper 20 to permit an influx of air for use in conjunction with the air admitted through the lighted end of the cigarette to dilute the tobacco smoke stream. The treated area burns at an accelerated rate when the burning coal reaches it, aided by the additional air admitted through the spreading of the slit. FIG. 6 is a vertical sectional view schematically showing treated area 21 and slit 22 (exaggerated somewhat) extending through area 21 and wrapper 20 to tobacco 18 beneath. These slits should be from 0.5 to 2.0 millimeters in length. FIG. 7 shows a cigarette 10' having the same essential construction as the cigarette 10 of FIG. 1. The difference lies in the fact that the treatment and perforations areas extend over about one-third the length of the cigarette from the mouthpiece in FIG. 7. Prime numerals of the identifying numerals of FIG. 1 are employed to denote corresponding parts.
The agent for accelerating the burn rate of the wrapper is preferably potassium nitrate (KNO 3 ). Treated area 16 of FIG. 2 can be formed by applying to the cigarette wrapper an aqueous solution of potassium nitrate of about 30 percent by weight to form a strip about 4 millimeters in width. The water from the solution is then evaporated to leave a thin residue or coating of potassium nitrate on the cigarette wrapper. The treated area is then pierced to form an aperture (e.g. a slit, perforation or the like) which extends through the treated area and wrapper to the tobacco beneath. Other burn accelerating agents can also be employed.
Although the cigarette depicted in the drawings is of the filter type, this invention is also applicable to non-filter type cigarettes. The wrapper treatment described above need not extend for the entire length of the cigarette. It can be applied to as little as one-third the length of the cigarette, starting from the mouthpiece, or may extend any other distance up to the full length. While the synergistic effect of the treatment and apertures in reducing components of the smoke is still realized, there is,of course, some decrease in the amount of removal as shorter lengths of the cigarette are treated.
For the purposes of giving those skilled in the art a better understanding of the invention and a better appreciation of the advantages of the invention, there is given herein data illustrative of the markedly improved capacity of the cigarette designed in accordance with this invention to substantially reduce the delivery of tar and other smoke constituents.
Table I below shows a cigarette in Example 1 treated in a manner similar to that of FIG. 2 with potassium nitrate to accelerate burning of the cigarette wrapper. Examples A, B and C are beyond the scope of this invention and are presented in Table I for comparative purposes with Example 1 of this invention. Example C was perforated and then treated with potassium nitrate so that a residue or coating of potassium nitrate covered the perforations. In Example C, as the burning coal approached the potassium nitrate-coated perforations, the potassium nitrate is removed from the aperture by burning to permit air to enter through the perforations. All cigarettes in the Examples were smoked on a constant vacuum smoking machine at one puff per minute to a point 3 millimeters from the tip. Each puff was of 2 seconds duration and was 35 milliliters in volume.
TABLE I
Ex. Treatment Tar Delivery Nicotine Tar/ Per Cigar- Delivery Nicotine ette (mg) Per cig- Ratio arette (mg) ____________________________________________________________ ______________ 1 treated with 8.3 1.16 7.2 KNO 3 with perforations extending through coating and wrapper to tobacco A untreated 22.6 1.63 13.9 B perforated but untreat- 17.8 1.44 12.4 ed C perforated and 13.8 1.19 11.6 treated with KNO 3 with KNO 3 coating extend- ing over per- forations in cigarette wrapper ____________________________________________________________ ______________
As can thus be seen from Table I, Example 1 had substantially reduced tar and nicotine delivery when compared to Examples A, B or C. It is to be noted that Example C has a tar delivery of 13.8 milligrams while Example 1, in accordance with this invention, has a tar delivery of only 8.3 milligrams which represents a substantial reduction in this smoke constituent. Moreover, the nicotine delivery and tar/nicotine ratio are also markedly reduced.
Table II below shows Example 2 treated with potassium nitrate in a manner similar to that pictured in FIG. 5 of the drawings. Examples D, E, F and G are beyond the scope of this invention and are included for comparative purposes with Example 2 of this invention. All Examples listed in Table II were smoked in the same manner described in the Examples of Table I. Example D is an untreated cigarette, while Example E is a cigarette having a strip of potassium nitrate coating but without apertures of any kind extending through the coating or cigarette wrapper. Example F is a cigarette having a plurality of slits extending from the mouthpiece to the end to be lighted but having no burn promoting coating. Example G is a cigarette having a plurality of slits which was first slit and then treated with potassium nitrate so that a potassium nitrate coating covered the slits. In Example G, as the burning coal advances, the potassium nitrate coating is burned from the slit to permit air intake through the slits. ##SPC1##
It is to be noted that there is a marked decrease in delivery of smoke constituents such as nicotine, tar, phenol, cyanide, nitrogen oxides and acetaldehyde as shown in Table II. When taken collectively this represents a substantial reduction in smoke constituents.
Table III below shows the percentage decrease in delivery of smoke constituents including particulate matter, nicotine, tar, phenol, cyanide, nitrogen oxides, and acetaldehyde between Example 1 and Example B. In the same manner, Example 2 is compared with Example F having slits but without potassium nitrate.
TABLE III ------------------------------------------------------------ --------------- Decrease in Delivery of Smoke Constituents (%)
Example dry TPM 1 Nicotine tar phenol cyanide Acet- Compari- (total) aldehyde son 1 with 50 19 53 49 39 12 B 2 with 30 24 31 38 43 20 F ____________________________________________________________ ______________
The reduction of all smoke constituents listed in Table III is substantial. In particular, it should be noted that Example 1 of this invention reduces the tar delivery by 53 percent when compared to an untreated perforated cigarette while Example 2 reduces the tar delivery by 31 percent, the phenol by 38 percent and the cyanide by 43 percent. The overall reduction therefore of smoke constituents is substantial.
Table IV below shows the percentage decrease in the delivery of smoke constituents and compares Example 1 with Example C and Example 2 with Example G.
TABLE IV
Decrease in Delivery of Smoke Constituents (%)
Example dry nico- tar phenol cyanide nitro- Acet- Compari- TPM 1 tine (total) gen aldehyde son oxides 1 with 37 3 40 10 7 12 7 C 2 with 28 22 29 28 29 21 22 G ____________________________________________________________ ______________
The data presented in Table IV clearly show the substantial and unexpected decrease in delivery of smoke constituents by Examples 1 and 2 of this invention. Example 1 reduces the tar delivery by 40 percent while Example 2 decreases the tar delivery by 29 percent. Each smoke constituent shown in Table IV is reduced so that the overall reduction is quite substantial.
Although the complete theory upon which this invention is based is not entirely understood at this time, it is believed that the effect of the perforation, slit or other aperture in combination with a burn promoting agent applied to the cigarette wrapper results in a synergistic effect which substantially reduces the delivery of smoke constituents. The data shown in Tables III and IV indicate that the combination of aperture and potassium nitrate treatment in accordance with this invention does not produce an additive effect but instead results in a decrease far in excess of expected results.
Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand.
This invention relates to an improved cigarette having means for reducing the delivery of smoke constituents.
Much effort in the field of cigarette research is directed to the problem of eliminating or reducing products contained in cigarette smoke. One approach to this problem has been the use of holes in the cigarette which permit air to enter the smoke stream as the cigarette is smoked to dilute the smoke with air. Another approach is to place a sealant over circumferentially spaced holes in the cigarette. The sealant vaporizes as the burning coal approaches to permit air to enter the smoke stream through the hole and prevent the combustion temperature from exceeding a predetermined limit. These and other approaches to the problem have reduced somewhat the products contained in the cigarette smoke but not to a level sufficient to substantially reduce the tar delivered with the smoke to a desired level.
BRIEF SUMMARY
A cigarette has now been developed which substantially reduces the delivery of smoke constituents by means of air dilution of the smoke stream.
An object of this invention therefore is to provide an improved cigarette which substantially reduces the delivery of tar and other smoke products.
Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a side elevation view of a cigarette treated with a burn accelerating agent applied to the wrapper over triangular-shaped, perforated areas;
FIG. 2 is a side elevation view of a cigarette treated with a burn accelerating agent applied to the wrapper as a perforated strip;
FIG. 3 is a close-up view of the perforations and treated area of FIG. 2;
FIG. 4 is a fragmentary sectional view taken along the line 4--4 of FIG. 3;
FIG. 5 is a side elevation view of a cigarette treated with a burn accelerating agent applied as a strip which is provided with a series of slits extending longitudinally along the cigarette from the mouthpiece;
FIG. 6 is a vertical sectional view taken along the line 6--6 of FIG. 5; and
FIG. 7 is a side elevation view of a cigarette treated with a burn accelerating agent applied to the wrapper over triangular-shaped, perforated areas, the areas extending about one-third the length of the cigarette from the mouthpiece.
In accordance with this invention a burn accelerating agent is applied to preselected areas of a cigarette wrapper to accelerate the burn rate of the wrapper. These treated areas are provided with an aperture which extends through the coating or agent residue on the surface and the wrapper. When the cigarette is smoked, the treated areas of the cigarette wrapper burn more rapidly to permit air to enter the smoke stream at a point ahead of the burning coal which, in combination with the air entering through the aperture, substantially reduces the delivery of tar and other constituents in the smoke. Because of the aperture, some air is passed through the wrapper with each puff. It is believed that passage of air through the aperture causes the portion of the wrapper surrounding the aperture to be raised from the tobacco column and thus causes more rapid burning when the burning coal reaches the area.
PREFERRED EMBODIMENTS
FIG. 1 shows cigarette 10 having mouthpiece 11 and a burn rate accelerating agent applied to wrapper 20 in a plurality of triangular-shaped treated areas 12, 13 and 14 extending from the mouthpiece to a point somewhat short of the end to be lighted 25. Although treated areas 12, 13 and 14 are perforated, FIG. 1 only shows treated area 13 having perforations 15 distributed substantially over its entire length. As cigarette 10 is smoked, the burning coal of the lighted end approaches the apex end of triangular-shaped areas 12, 13 and 14. The burn agent will then promote accelerated burning of the treated areas of cigarette wrapper 20 to permit an influx of air into the tobacco smoke stream at a point ahead of the burning coal. The treated areas get progressively larger toward mouthpiece end 11 of cigarette 10 due to the triangular pattern to permit a larger volume of air to enter the smoke stream as the cigarette is smoked closer to mouthpiece end 11. The dilution effect substantially reduces the tar delivery which increases considerably as the cigarette is smoked. Perforations 15 extend through the residue or coating of the burn agent of area 13 and wrapper 20 to the tobacco beneath. The combined effect therefore is to have air dilution in the smoke stream coming from the perforations 15 and the accelerated burn area 13 of wrapper 20.
FIG. 2 shows cigarette 10 provided with a treated area or strip of burn promoting agent 16 applied to wrapper 20 and extending from mouthpiece end 11 toward the end to be lighted 25. Since the air dilution effect on the tar and other products in the smoke is minimized close to cigarette end 25, strip 16 extends to a point somewhat short of end 25. Treated area 16 is provided with perforations 17 to allow air intake. FIG. 3 is a close-up view of treated area 16 and perforations 17. As shown in FIG. 3, tobacco 18 is exposed to the atmosphere by means of perforation 17 which extends through the residue or coating of treated area 16 and wrapper 20. In this connection, FIG. 4 shows perforation 17 extending completely through treated area 16 and wrapper 20 to expose tobacco 18 beneath. It should be noted that treated area 16 is shown in FIG. 4 as a separate layer. Such a showing is intended to be schematic and in actual application of this invention the burn promoting agent may be absorbed by wrapper 20 and leave no residue, coating or layer as shown in FIG. 4. The perforations shown in FIGS. 1 through 4 should be at least 0.5 millimeters in diameter.
FIG. 5 shows an additional embodiment of this invention in which a treated area 21 extends longitudinally along the cigarette from mouthpiece end 11 toward end 25. Cigarette 10 is provided with a plurality of slits 22 extending longitudinally along wrapper 20. As the burning coal progressively reaches each of slits 22, the area surrounding the slit is opened to admit additional air. Slits 22 extend through treated area 21 and wrapper 20 to permit an influx of air for use in conjunction with the air admitted through the lighted end of the cigarette to dilute the tobacco smoke stream. The treated area burns at an accelerated rate when the burning coal reaches it, aided by the additional air admitted through the spreading of the slit. FIG. 6 is a vertical sectional view schematically showing treated area 21 and slit 22 (exaggerated somewhat) extending through area 21 and wrapper 20 to tobacco 18 beneath. These slits should be from 0.5 to 2.0 millimeters in length. FIG. 7 shows a cigarette 10' having the same essential construction as the cigarette 10 of FIG. 1. The difference lies in the fact that the treatment and perforations areas extend over about one-third the length of the cigarette from the mouthpiece in FIG. 7. Prime numerals of the identifying numerals of FIG. 1 are employed to denote corresponding parts.
The agent for accelerating the burn rate of the wrapper is preferably potassium nitrate (KNO 3 ). Treated area 16 of FIG. 2 can be formed by applying to the cigarette wrapper an aqueous solution of potassium nitrate of about 30 percent by weight to form a strip about 4 millimeters in width. The water from the solution is then evaporated to leave a thin residue or coating of potassium nitrate on the cigarette wrapper. The treated area is then pierced to form an aperture (e.g. a slit, perforation or the like) which extends through the treated area and wrapper to the tobacco beneath. Other burn accelerating agents can also be employed.
Although the cigarette depicted in the drawings is of the filter type, this invention is also applicable to non-filter type cigarettes. The wrapper treatment described above need not extend for the entire length of the cigarette. It can be applied to as little as one-third the length of the cigarette, starting from the mouthpiece, or may extend any other distance up to the full length. While the synergistic effect of the treatment and apertures in reducing components of the smoke is still realized, there is,of course, some decrease in the amount of removal as shorter lengths of the cigarette are treated.
For the purposes of giving those skilled in the art a better understanding of the invention and a better appreciation of the advantages of the invention, there is given herein data illustrative of the markedly improved capacity of the cigarette designed in accordance with this invention to substantially reduce the delivery of tar and other smoke constituents.
Table I below shows a cigarette in Example 1 treated in a manner similar to that of FIG. 2 with potassium nitrate to accelerate burning of the cigarette wrapper. Examples A, B and C are beyond the scope of this invention and are presented in Table I for comparative purposes with Example 1 of this invention. Example C was perforated and then treated with potassium nitrate so that a residue or coating of potassium nitrate covered the perforations. In Example C, as the burning coal approached the potassium nitrate-coated perforations, the potassium nitrate is removed from the aperture by burning to permit air to enter through the perforations. All cigarettes in the Examples were smoked on a constant vacuum smoking machine at one puff per minute to a point 3 millimeters from the tip. Each puff was of 2 seconds duration and was 35 milliliters in volume.
TABLE I
Ex. Treatment Tar Delivery Nicotine Tar/ Per Cigar- Delivery Nicotine ette (mg) Per cig- Ratio arette (mg) ____________________________________________________________ ______________ 1 treated with 8.3 1.16 7.2 KNO 3 with perforations extending through coating and wrapper to tobacco A untreated 22.6 1.63 13.9 B perforated but untreat- 17.8 1.44 12.4 ed C perforated and 13.8 1.19 11.6 treated with KNO 3 with KNO 3 coating extend- ing over per- forations in cigarette wrapper ____________________________________________________________ ______________
As can thus be seen from Table I, Example 1 had substantially reduced tar and nicotine delivery when compared to Examples A, B or C. It is to be noted that Example C has a tar delivery of 13.8 milligrams while Example 1, in accordance with this invention, has a tar delivery of only 8.3 milligrams which represents a substantial reduction in this smoke constituent. Moreover, the nicotine delivery and tar/nicotine ratio are also markedly reduced.
Table II below shows Example 2 treated with potassium nitrate in a manner similar to that pictured in FIG. 5 of the drawings. Examples D, E, F and G are beyond the scope of this invention and are included for comparative purposes with Example 2 of this invention. All Examples listed in Table II were smoked in the same manner described in the Examples of Table I. Example D is an untreated cigarette, while Example E is a cigarette having a strip of potassium nitrate coating but without apertures of any kind extending through the coating or cigarette wrapper. Example F is a cigarette having a plurality of slits extending from the mouthpiece to the end to be lighted but having no burn promoting coating. Example G is a cigarette having a plurality of slits which was first slit and then treated with potassium nitrate so that a potassium nitrate coating covered the slits. In Example G, as the burning coal advances, the potassium nitrate coating is burned from the slit to permit air intake through the slits. ##SPC1##
It is to be noted that there is a marked decrease in delivery of smoke constituents such as nicotine, tar, phenol, cyanide, nitrogen oxides and acetaldehyde as shown in Table II. When taken collectively this represents a substantial reduction in smoke constituents.
Table III below shows the percentage decrease in delivery of smoke constituents including particulate matter, nicotine, tar, phenol, cyanide, nitrogen oxides, and acetaldehyde between Example 1 and Example B. In the same manner, Example 2 is compared with Example F having slits but without potassium nitrate.
TABLE III ------------------------------------------------------------ --------------- Decrease in Delivery of Smoke Constituents (%)
Example dry TPM 1 Nicotine tar phenol cyanide Acet- Compari- (total) aldehyde son 1 with 50 19 53 49 39 12 B 2 with 30 24 31 38 43 20 F ____________________________________________________________ ______________
The reduction of all smoke constituents listed in Table III is substantial. In particular, it should be noted that Example 1 of this invention reduces the tar delivery by 53 percent when compared to an untreated perforated cigarette while Example 2 reduces the tar delivery by 31 percent, the phenol by 38 percent and the cyanide by 43 percent. The overall reduction therefore of smoke constituents is substantial.
Table IV below shows the percentage decrease in the delivery of smoke constituents and compares Example 1 with Example C and Example 2 with Example G.
TABLE IV
Decrease in Delivery of Smoke Constituents (%)
Example dry nico- tar phenol cyanide nitro- Acet- Compari- TPM 1 tine (total) gen aldehyde son oxides 1 with 37 3 40 10 7 12 7 C 2 with 28 22 29 28 29 21 22 G ____________________________________________________________ ______________
The data presented in Table IV clearly show the substantial and unexpected decrease in delivery of smoke constituents by Examples 1 and 2 of this invention. Example 1 reduces the tar delivery by 40 percent while Example 2 decreases the tar delivery by 29 percent. Each smoke constituent shown in Table IV is reduced so that the overall reduction is quite substantial.
Although the complete theory upon which this invention is based is not entirely understood at this time, it is believed that the effect of the perforation, slit or other aperture in combination with a burn promoting agent applied to the cigarette wrapper results in a synergistic effect which substantially reduces the delivery of smoke constituents. The data shown in Tables III and IV indicate that the combination of aperture and potassium nitrate treatment in accordance with this invention does not produce an additive effect but instead results in a decrease far in excess of expected results.
Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand.