US 3255760 A
Description (OCR text may contain errors)
. the extraction.
United States Patent 3,255,760 rouacco rnonucr wrncrr ruonucus LESS TARS William A. Selke, Stoclrbridge, Mass, assigrzor to Kimberly-(Hark Corporation, Neenah, Wis, a corporation of Delaware N0 Drawing. Filed Aug. 3, 1962, Ser. No. 214,500 Claims. (Cl. 131-8) t-o cigars, cigarettes, smoking tobacco, and similar products affording a means tor enjoyment of the flavor and aroma of burning tobacco.
It is a general object of the invention to provide-a tobacco product having reduced content of those materials Whose pyrolysis generates tars Without contributing to the characteristic flavor of the smoke.
Another object is to achieve this result without impairment of the general appearance, texture, aroma, and desirable smoking qualities of the product.
Another object is to produce a tobacco product, and smokable articles prepared from it, having the advantageous characteristics referred to, by a procedure which is thoroughly practicable on a commercial scale and economically feasible.
It is Well known that the composition of natural tobacco leaf includes aromatic and resinous substances, alkaloids, sugars and salts of various kinds, and crude fibers. The aromatic and resinous substances provide desirable smell and taste during pyrolysis. The burning of the fibers produces only the characteristic smoke of burning cellulose and contributes very little to the aroma. Not only are they not essentialto the smoking qualities, but they are definitely undesirable because among the products of pyrolysis are tars which may be harmful. It is a general object of this invention to provide a method of treatment which serves, in effect, to eliminate the fibers and to replace them with a substitute noncombustible non-toxic carrier for the more desirable values of the tobacco leaf.
Another objective is to provide an improved tobacco product in sheet form having a reduced content of the cellu-losic fibers whose presence contribute-s little to smoking enjoyment and which create products of combination that may be harmful.
An illustrative procedure conforming essentially to the objectives and features of the invention is depicted in the following flow chart:
The original tobacco may be in leaf or other form, preferably macerated or comminuted in preparation for The extraction is facilitated by the use of hot Water, and generally withdraws from 25% to 60% by weight of the starting material. The fibrous residue Patented June 14, 1966 ice may be discarded at once, although (as indicated in dotted lines) a further extraction with organic solvents may be resorted to, if desired, to recover selected values still retained by the fibers. Ethyl ether, other low others, acetone, or other low boiling ketones, are examples of such solvents.
The non-combustible fibers should be of nontoxic kind, bondable to produce an absorbent paper by conventional paper-making equipment and techniques. Glass fibers are excellent for the purpose. Absestos shorts are also suitable, and are preferred because they are less expensive. The fibers may range in size from diameters as low as 0.05 micron t-o diameters of the order of 5.5 microns or even more. Blends of these with each other, or with other inorganic fibers may be used. To facilitate the bonding together of the fibers during the formation of the paper web, some natural cellulosic fibers may be used, e.g., beaten wood pulp fiber. Even some of the extracted tobacco leaf could be beaten in conventional paper-making equipment and used as part of the binder, although it ismuch less effective than Wood pulp. Under some circumstances, especially if acidity is carefully controlled, paper made Wholly of organic fibers can be produced. But for the purpose of this invention, it is sufiicient if the paper is composed essentially of fibers that are non-combustible. The weight fraction of such cellulosic fibers as may be used can be maintained at a low level if the fibers are well beaten so as to make them most eifective as a bonding agent.
Preferably the basis weight of the paper is in the range of 8 to pounds per ream, which is roughly equivalent to the Weight characteristics of natural tobacco leaf.
If desired, mineral fillers can be added to regulate the physical nature of the paper and to control the rate of burning of the final product. For example, alumina is effective because it becomes hydrated during the papermaking process and subsequently liberates the water to absorb heat (and thereby control burning rate) during the ultimate burning of the smokable article.
As indicated in the flow chart, the tobacco extract is introduced into the paper after a sel-fasustaining web has been formed. This extract may be only the aqueous extract (suitably concentrated to any desired degree), or it may include the substances obtained from the optional organic extraction procedure. The application of the extracted tobacco material may be achieved in any appropriate manner, as by spraying, saturating, or otherwise. The dry solids of the tobacco extract should preferably be present in the resultant sheet in the same proportion as, or a proportion smaller than, that which existed in the original natural tobacco material. For example, if from 25 to 60% of tobacco material is withdrawn during the extraction, then from 15 to of the material may be introduced into the paper web.
Combustible diluents may be added to the tobacco .liquor before it is applied to the paper web. Such diluents are of an origin other than tobacco and can be employed .to tone down the tobacco effect and produce a more neutral smoke. Any aqueously soluble combustible material that produces a neutral non-toxic smoke, such as water-soluble cellulose derivatives can be used. Dextrin has been found to be a desirable additive for this purpose, but other water-soluble organic materials, of non-toxic character can be used.
The final impregnated sheet can be employed in various Ways in the preparation of smokable articles. For example, in the manufacture of cigarettes or smoking tobacco it would be shredded, then used by itself, or blended with natural tobacco, in conventional cigarette-making machinery. In the manufacture of cigars, it may be retained in larger sheet form. In any case, the basic manufacturing procedures do not require any essential modification.
The characteristics of the ultimate smokable article, whatever its nature, are high-lighted by the absence, from the products of combustion, of the major portion of the tars that would otherwise be present if the tobacco fibers had not been removed and replaced. The non-combustible fibers do not materially alter the burning qualities, nor the texture or appearance, of the article except in regard to the ash. In cigarettes, for example, the burning produces more ash than usual. If fusible fibers, such as glass, are employed in the carrier sheet this ash will be solid and adherent. If the carrier sheet is composed of asbestos, Carborundum or potassium titanate fibers, the ash will be non-adherent.
Some specific examples of the procedure, as applied to the manufacture of cigarettes, are as follows:
treatment with boiling water. Then the extract was concentrated using a llaboratory rotary vacuum evaporator, until the extract contained dry solids by weight. Dextrin was then added in an amount equal to about 7%. by weight of the solution.
A paper was produced, composed of 40% glass microfibers, 50% asbestos shorts, and 10% beaten unbleached kraft wood pulp. The glass fibers had diameters whose average was in the range of 0.75 to 1. 6 microns. The kraft pulp was of a kind whose drainage rate was 60 (Canadian standard freeness). The basis weight of the paper was 14 pounds, i.e., it weighed 14 pounds per ream (480 sheets, x
This paper was saturated with the tobacco extract by repeated spraying and drying, until the tobacco solids equalled the weight of the original sheet, i.e., the finished product was composed of Percent Base paper Tobacco 40 Dextrin 20 This product was then shredded and made into cigarettes, which were flavorful and entirely satisfying from a smokers standpoint.
EXAMPLE II The procedure of Example I was followed, with the exception that the amount of glass fibers was halved, and the balance replaced by activated alumina. The product was shredded and made into cigarettes, which were satisfactory and had a good taste and aroma.
Comparative tests Cigarettes made of the original tobacco, as well as cigarettes made in accordance with Examples I and II, were smoked in a conventional cigarette testing machine in which three puffs (each 70 milliliters in volume) per minute were taken. The tars were collected on a glass paper filter and weighed. The results were as follows:
Tars (Milli- Cigarette N0. of Putl's grams per cigarette) Original Tobacco 18 84 Modified Product (Example I) without alumina 9 19 Modified Product (Example II) with alumina 18 23 It will thus be seen by the new procedure a highly advantageous result can be achieved. It is to be understood, of course, that the invention is not restricted to cigarettes.
What is claimed is:
.1. A cigarette whose filler includes shreds of paper formed essentially of non-combustible non-toxic fibers and having tobacco extract material incorporated therewith.
2. A cigarette as defined in claim 11, wherein the paper of which said shreds are made contains a combustible diluent that produces neutral non-toxic smoke.
3. A cigarette as defined in claim 2 wherein said diluent is dextrin.
4. A cigarette as defined in claim 1, wherein the paper of which said shreds are made contains a mineral filler to retard the burning rate.
5. A cigarette as defined in claim 4, wherein said mineral filler is alumina.
6. A process of making a tobacco product for use in a smokable article, which comprises 1) treating tobacco (a) to separate from it a substantial proportion of the fibrous material whose pyrolysis generates tars, and
(b) to retain the non-fibrous remainder in the form of a solution,
(2) forming a fibrous sheet consisting essentially of non-combustible fibers, and
(3) introducing said non fibrous remainder into intimate association with said sheet, in such an amount that the proportion of non-fibrous to fibrous material is substantially the same as the proportion present in natural tobacco.
7. A process of making a smokable tobacco product for use as cigarette filler material, which comprises 1) treating tobacco (a) to separate from it a substantial proportion of the fibrous material whose pyrolysis generiates tars, and
('b) to retain the non-fibrous remainder in the form of a solution,
(2) tforming a fibrous sheet consisting essentially of non-combustible fibers,
(3) introducing said non-fibrous remainder into intimate association with said sheet, in such an amount that the proportion of non-fibrous to fibrous material is substantially the same as the proportion present in natural tobacco, and
(4) shredding said sheet.
8. A process as defined in claim 6, including the step of also introducing into said sheet an agent adapted to slow the rate of combustion of the tobacco constituents.
9. A process as defined in claim 8, in which said agent is activated alumina.
10. A process as defined in claim 6, in which the tobacco treatment (1) includes a first extraction of the tobacco with water, and a subsequent additional extraction of the residual fibrous material with an organic solvent, both solutions being introduced into said fibrous sheet (2).
References Cited by the Examiner UNITED STATES PATENTS 50,038 9/1865 Rotfee 131-17 253,841 2/1882 Carpenter. 445,43 8 1/1891 Bin gham. 1,016,844 2/1912 Moonelis 13 1-17 1,020,864 3/1912 Whitmore 131-15 1,338,927 5/1920 Goodfellow 131--17 (Other references on following page) UNITED 5 6 STATES PATENTS FOREIGN PATENTS Whiteley 131-4 17,037 1912 Great Britain. Betts 131-'-15 38 49 4/195 8 Great Britain. Garber 131-17 276,709 10/1951 Switzerland.
Frankenburg 131--17 5 l Jurgensen 131 17 SAMUEL KOREN, Primary Exammer. Haden 131-47 F- RAY CHAPPELL, ABRAHAM G. STONE, MEL- Howand 131 17 V N D. REIN, Examiners.