US3002863A - Smoking tobacco mixture and method of making - Google Patents

Description

Oct. 3, 1961 3,002,863

SMOKING TOBACCO MIXTURE AND METHOD 0N MAKING l R. J. SHAW Filed June 20, 1960 E mm D A m55 o ATR D 0 RAE N A05 E .JWN L B 5U .u m L w 0 w 5 E l mwa www gm 3 m 0 m lml 3,002,863 SMQKING TOBACCO MIXTURE NmTHU F G Richard I. Shaw, 3241 N. El Tovar, Tucson, Ariz. Flledlnne 20, 1960, Ser. No. 37,135 17 Claims. (Cl. 13b-17) The present invention relates to a smoking tobacco mixture and method of making same. The invention provides a smoking tobacco mixture designed to remove irritating substances from the smoke before reaching the mouth and lungs of the smoker. Thereby, the irritation to the smoker is decreased and the pleasure and enjoyment of the smoking increased.

Heretofore, various attempts have been made to eliminate the irritating materials from tobacco smoke. lt has been recognized that during the combustion of tobacco in a cigarette, pipe, or cigar, several steps occur. initially, when the cigarette is lighted, the tobacco at the end must berheated to the kindling temperature. This involves driving the water out of the tobacco, by supplying the latent heat required to vaporize the water. Some tibers or shreds of tobacco must be heated to approximately 1,000 degrees Fahrenheit, a dull red heat. This process is aided by drawing air through the cigarette while the kindling agent, such as a lighted match, is held near or in contact with the cigarette.

When the tobacco is ignited, moisture and some of the lower boiling undcsired'rnaterials arising from the combustion of said tobacco, which may be of an oily nature, are drawn away from the combustion zone of the tobacco as a vapor. Some of this vapor subsequently condenses on the cold tobacco remote from the heated end. The heat carried by the vapors is transmitted to the tobacco and thereby raises the temperature of the tobacco. As the tobacco at the lighted end of the cigarette ignites, it supplies further heat in the form of hot gases. These hot gases follow the iirst products of combustion through the cigarette, further raising the temperature of the tobacco, revaporizing the condensed moisture and cer-tain undesired materials such as oils, and heating the freshly dried tobacco to the cracking temperature at which the molecules composing the tobacco begin to break up.

Generally, this combustion of the tobacco is an exothermic reaction which supplies heat to accelerate the combustion process. At temperatures slightly higher than the cracking temperatures, the carbonaceous residue from the cracking is oxidized to produce carbon dioxide and carbonI monoxide. At these higher temperatures,

`certain materials produced by t-he cracking, such as methanol, are also oxidized. This process of destruction of the lighter oils is accelerated if their movement through the cigarette is slowed by any means, thereby bringing them closer to the combustion zone.

In general, there are several methods of slowing the movement of theproducts of destructive distillation. Firstly, the tobacco can be packed tighter, but this produces poor drawing characteristics. Secondly, an inert ller can be introduced into the tobacco mixture. Some fillers previously proposed include diatomaceous earth, fullers earth, bentonite, or calcined clay. Such fillers plug the pores or interstices between the shreds of to* bacco, thus producing unsatisfactory drawing characteristics. v

Thirdly, an adsorbent or absorbent can be added, which will physicallyhold the undesired oils but not the moisture, until the `zone of combustion reaches the point in the cigarette where the oils are held and they are consumed or burned by the hot gases which contain some oxygen.

' Attempts to do this have been made by adding charcoal,

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terials have been pressed into the tobacco, or mixed with it after shredding, or placed in a separate portion of the cigarette, as in filter tips. The manufacturing of the straight cigarettes.

When the adsorbent is added to the tobacco it has generally been either in relatively large pieces or in a tine powder. T he large pieces are generally effective on their surface only because there is no force to, move the oils into the large particles after the surface is coated. The small particles of powder fineness generally lie primarily against the tobacco shreds or pieces. During the first step of liquifaction or formation of undesired irritating materials in 4the tobacco, asphaltic type compounds condense and cover the small adsorbent particles. Thus the particles cannot function to adsorb the lighter irritating materials that float in the smoke as gases or entrained droplets.

It is an object of this invention to provide a smoking mixture including tobacco and materials for retarding the flow of said irritants, such as tars, so that 4they are den stroyed by combustion.

lt is a further object of this invention to provide a method of making a smoking mixture for the elimination of irritants from the smoke during subsequent combustio of the tobacco.

It is a further object of this invention to increase the health and enjoyment of the smoking public by removing irritating and dangerous materials from their smoke.

It is a further object of this invention to provide a smoking mixture of tobacco and adsorbing particles interspersed within the air passages between the tobacco pieces, rwhereby irritants are adsorbed and subsequently destroyed by combustion.

lt is a further objectof this invention to provide an adsorbing element capable of adsorbing undesirable materials from tobacco smoke and holding the materials for subsequent combustion. v

The smoking mixture of the invention includes tobacco leaves or shreds mixed with adsorbing members. The adsorbing members are formed from heat-resistant, long fine fibers coated vm'th activated carbon. The heat-resistant iibcrs support the activated carbon in the air passages of the smoking mixture to improve the contact of the carbon with the stream of gases. Among the heatresistant fibers which can be used are asbestos fibers; carbonized organic fibers; glass fibers; silica bers; high melting metal fibers as iron, and the like.

The formation of the adsorbing member can be accomplished by coating the heat resistant fiber, such as an asbestos ber, with a readily-cornbustible organic material. Among the organic coating materials which can be used is a solution or emulsion of an organic substance such as asphalt, coal-tar, solid petroleum materials, cut back petroleum oil, and the like. Among the solvents which can beused are naphtha, gasoline and the like, When an emulsion is used, water can be employed as the dispersion medium. Next, the coated fibers are heated in the absence of air, or at least in the absence of oxygen, to temperatures of about 1500 degrees Fahrenheit. Thereby a thin film of carbon in an activated form is produced baked to the surface of the asbestos. The bond between the activated carbon and the asbestos is suiiicientlyV strong that the carbon is not removed by abrasion of the coated fibers against each other. The coated fibers are mixed with tobacco to form a smoking mixture.

For a better understanding of this invention and its other objects, advantages and details, reference is now made to the present preferred embodiment of the invention which is shown for purposes of illustration only in the accompanying drawing.

accasss tially coated with activated carbon;

FIG. 2 is a fragmentary elevation view, partly in section of a cigarette according to the invention and showing the adsorbing elements located in the air passages between the tobacco shreds;

FIG. 3 is an end elevation view of the cigarette illustrated in FIG. 2, and,

FIG. 4 is a ow sheet of a process of forming a cigarette according to the invention.

In order to produce the adsorbing members 10 illustrated in FIG. 1, saturate long ber asbestos with an emulsion of asphalt in water. Allow the mixture to drain and then dry in an oven at about 230 degrees Fahrenheit for about four to about six hours. After the drying in the oven, place the coated bers in a mullie so as to substantially exclude oxygen. Raise the temperature by heating for a period of about two hours to about 1380-1500 degrees Fahrenheit. Hold the mixture at this temperature for about thirty minutes. At the end of this time, turn ol -the oven and allow the mixture slowly vto return to room temperature. The cooking of the asphalt is complete when there is no coloration produced by adding a sample of the asbestoscarbon mixture to petroleum ether. Remove and discard the asbestos from which the carbon has been completely burned ol. There is thus obtained asbestos bers coated with activated carbon.

Next, blend with tobacco intended for smoking the coated asbestos bers, which are the adsorbing elements or members. 'Ihe tobacco can be in leaf or shredded form prior to producing cigars, cigarettes or pipe tobacco.

Referring to FIG. l, each adsorbing member or element 10 includes an asbestos ber 12 and an outer coating 14 of activated carbon. The adsorbing elements and the tobacco are mixed in suitable percentages. The preferred range is about 0.1 to 10 percent of elements based on the total weight of the resulting smoking mixture.

Referring to FIGS. 2 and 3, the mixture of tobacco shreds 16 and adsorbing elements 10 is incorporated within a cigarette paper 18 rolled to form a conduit for smoke produced by combustion of Ithe tobacco. llt will be seen that most of the adsorbing elements are not in intimate contact with the tobacco shreds, but by the nature of the random curve lines ofthe elements, the adsorbing elements 10 cross and recross the openings between the tobacco shred 16. Thus, most of the length of the adsorbing elements is in the pores between the tobacco shreds 16. Since a small percentage of asbestos adsorbing elements 10 are used and since the elements are very line, the elements occupy little of the pores or open space between the tobacco shreds. Thus there is little impeding of the natural 'draw of the cigarette.

When the cigarette illustrated in FIGS. 2 and 3 is lighted, and the tobacco commences to burn, the products of combustion and destructive distillation of the tobacco pass along the cigarette. Many of the undesirable and irritating materials are adsorbed by the activated carbon coating on the asbestos bers of the elements 10. Among such irritants are tars, aldehydes, alcohols, ketones, acids, amines, various cyclic organic compounds, phenols, etc., which are passed along the cigarette in gaseous form or as small droplets of liquid.

Because of the advantageous arrangement of the ad sorbing elements 10 in the open spaces between the tobacco shreds, the gases principally contact the activated carbon coatings whilel having small contact with the tobacco shreds. The vapors sweep around the adsorbing elements l before they have heated the adjacent tobacco shreds to the temperature of destructive distillation. Although the elements are heated to high temadsorbing 4l perature, the adsorbing power of the activated carbon coatings is sutlicient for adsorption of the irritants.

The irritating and undesirable materials are held on the activated carbon coatings 14 until the zone of combustion advances to the particular adsorbing elements.

Then the materials adsorbed on the elements 10 are ignited and burned to produce inert or at least less-irritating compounds.

Since the activated carbon coatings 14 have little contact with the tobacco shreds 16, the flow of heavy tars from the tobacco shreds will not cover or mask the carbon coating lill. Thus the danger that coatings 14 will be rendered inert by a layer of heavy tar is obviated.

In cigarettes according to this invention, it has been found that the percentage of undesirable materials, tars and the like, removed from the smoke by the adsorbing members itl, varied directly with the amount of adsorbing material added to the tobacco. tFrom about -90 percent by weight of the undesirable materials may be removed according to this invention.

A measurement was made of tars and the like adsorbed from cigarette smoke. Various brands were tested, designated below simply as .A, B, C, et cetera. The procedure included removing the tobacco from yfour cigarettes of each brand, mixing the tobacco with carbon-asbestos adsorbing members of the invention, and rerolling the cigarettes. Next the cigarettes were weighed on au analytical balance and their weights recorded. Each cigarette was then attached to a lter type cigarette holder, into which was placed the weighed adsorbent capsule. The cigarette was lighted andair at the rate of 250 milliliters per minute drew the smoke through the lter trap by means of an electrically-driven pump. Four cigarettes of each sampling were smoked in this manner through the same lter. 'Ihe lter was then dried and reweighed. The unsmoked portions of the `four cigarettes were weighed, and their weight subtracted from the total original weight of the four cigarettes. The increase in weight in the lter, representing the tars removed from the smoke of four cigarettes, was .then divided by the total weight of the cigarettes smoked, and the milligrams of tars per gram of tobacco was calculated. In the case of the lter -tip cigarettes, four with the tip were smoked and -four with the lter removed were smoked. The results of the measurement are tabulated as follows:

Column 1 Column 2 lColumn 3 Column 4 Brand oi Cigarette Percent Activated Carbon Coated Asbestos Untreated Filter Tip 29. 0 14. 0 0. l) L 2 37. 0 18. 7 2. 4 1. 2 2l). 6 1G. 1. l) 1. 8 37. il 24. 3 6. 0 30. 3 4. 2 3. 23. 2 3. 4 2. G 20. 9 7. 7 7.- 5

All figures in the body of the above table, columns 1-4, are milligrams of -tars recovered per gram of tobacco consumed.

While a present preferred embodiment of this invention has been illustrated and described, it will be recognized that the invention may be otherwise variously embodied and practiced within the scope of lthe following claims.

l claim:

l. A smoking mixture comprising a plurality of pieces of tobacco, and a plurality of adsorbing elements disposed in the spaces between said tobacco pieces, each said adsorbing element including a heat-resistant ber core and a coatingy of activated carbon around said core.

vated carbon.

4.y A method of forminga smoking mixture comprising the steps: mixing heat-resistant bers with readily combustible organic material; heating the mixture in substantial absence of oxygen to produce a coating of activated carbon on the surfaces of the bers; and, mixing the coated bers with tobacco.

5.' The invention as set forth in claim 4 wherein about onetenth to ten percent by weight of said coated bers is mixed with the tobacco.

6. The smoking mixture as set forth in claim 2 wherein said core is glass ber. i

7.,The smoking mixture as set forth in claim 1 wherein said core is silica ber.

8. The smoking mixture as set forth in claim 1 wherein said core is a high melting metal ber.

9. A cigarette as set forth in claim. 3 wherein said cores are asbestos bers.

10. A cigaretteas set forth in claim 3 wherein said cores `are glass bers.

11. A cigarette as set forth in' claim 3 wherein said cores are silica bers.

12. A cigarette as set forth in claim 3 wherein said cores are high melting metal bers.

13. A method as set forth in claim 4 wherein said heat resistant fibers are asbestos bers.

14. A method as set forth in claim 4 wherein said heat resistant bers are glass bers.

15. A method as set forth in claim 4 wherein said heat resistant bers are silica bers.

' 16. A method as set forth in claim 4 wherein said heat resistant bers are high melting metal bers.

17. A method as set forth in claim 4 wherein said combustible organic material is a carbonizable bituminous material.

References Cited in the le of this patent UNITED STATES PATENTS 445,438 Bingham J'an. 27, 1891 579,421 Campbell Mar. 23, 1897 1,808,707 Wiggins June 2, 1931 1,966,553 Kropp July 17, 1934 1,985,840 Sadtler Dec. 25, 1934 2,565,052 Sowa Aug. 21, 1951 2,708,441 Viglione May 17, 1955 2,714,385 Jackson Aug. 2, 1955 FOREIGN PATENTS 9,249 Great Britain 1895

Claims (1)

1. A SMOKING MIXTURE COMPRISING A PLURALITY OF PIECES OF TOBACCO, AND A PLURALITY OF ADSORBING ELEMENTS DISPOSED IN THE SPACES BETWEEN SAID TOBACCO PIECES, EACH SAID ADSORBING ELEMENT INCLUDING A HEAT-RESISTANT FIBER CORE AND A COATING OF ACTIVATED CARBON AROUND SAID CORE.

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