US2734510A

US2734510A - Preparing

Info

Publication number: US2734510A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

Feb. 14, 1956 G. P. HUNGERFORD :TAL 2,734,510

TOBACCQ SHEET MATERIAL AND METHOD OF FORMING 2 Sheets-Sheet l Filqd Aug. 25, 1955 INVENTOR GORDON P. HLNGERFORD DBE BERT F. JURGENSEN, JR.

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@wiwi mw; Bugo ATTO NEY lll G. P. HUNGERFORD ETAL 2,734,510

Feb. 14, 1956 Filed Aug. 25, 1955 FIG.2

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srnsusm OF FILM FORMING WET El "48 l El G. 4

Puma rosAcco ours? 120 .2 l 4 To wer wel g WWWIIVA'J v v l E45? :wf-2@ t miv/ml;v J/22 A Reuo/ms Excess x24 ToaAccQ ous? nolsveums H 30 TOBACCO WEB nsuovms wsa non cAsTme /32 sunncs LANTNTIHG WEI BRUSH OFF INVENTOR GORDON P. HUNGERFORD DELBERT F. JURGENSENgJR.

ATTO NEY PACKAGING 0R SHREDDING 0R GUTTHQ `1`52 United States Patent TOBACCO SHEET MATERIAL AND METHOD F FORMING Gordon P. Hungerford, Westport, Conn., and Delbert F. Jurgensen, Jr., Short Hills, N.J.,. assigncrs to American Machine & Foundry Company, a corporation of New Jersey Application August 25, 1955, Serial No. 530,561

49 Claims. (Cl. 131-15) This application is a continuationin part of copend'ng application Ser. No. 124,042 filed October` 28, 19.49, now abandoned;

This invention relates to improved reconstituted tobacco sheets, films, webs, strips and filaments, hereinafter usually referred to as tobacco sheet, or strip material, landv to improved methods of producing the same.4

The manufacturer of tobacco productsv generally buys tobacco in the form of whole leaves as` removed from the tobacco plant by the farmer. In processing this tobacco, the stem is frequently first removed and then further. processing proceeds as desired. In the casey of cigarette manufacture,.this includes aging, blending, casing and cutting the strip, which is the tobacco laminae remaining after removal of the stem, into shreds and then drying, cooling, screening and forming the shredded tobacco. intof cigarettes, followed by packaging. In all these operations; which involve much handling of the tobacco, waste fines and dust are formed. At the present time these was-te materials, stems, field scrap (farm damaged| leaves), fines and dust have. essentially no value. toy the tobacco manufacturer, and arev sold to. manufacturers. of` fertilizers,I and insecticides at afracton of acent per pound; MuchV of this waste tobacco material is of good quality from a smokingstandpoint. Indeed it is believed that this waste tobacco material contains a disproportionately high percentage of the very best quality smoking. tobacco, since the latter comprises the thinnest, lightest, most friable leaves which would most readily break up into. fines and dust on handling. These high quality fines are useless now only because of their physical form. A technique for processing this good tobacco'into a form which` would render it usuable in smoking articles without essential change in its smoking characteristics would therefore be attractive to a tobacco manufacturer since it would tend to reduce manufacturing costs.

It has been suggested previously that reconstitutedA tobacco strip material be made. by wet milling a mixture of tobacco in water to form therefrom a slurry'whicli can be converted, as by any well-known casting and drying method, into continuous self-supporting sheets.y and. strip material.

Other attempts to solve. the problem of forming ay satisfactory reconstituted tobacco sheet material. .could be cited', such as by forming, tobaccopaper usingv well-known paper-making techniques,y and also by formingcalendered tobacco impregnated films. However, despite. thiese at.- tempts, little success has been achieved:y and-v to our knowledge, none of these processes has ever been usedcom.- mercially. y

The' present invention constitutes a solution to. theproblem of reconstituting tobacco materials by converting them into reconstituted tobacco sheet or strip material .which can be used inthe same manner as natural leaf'tobacco in tobacco products such as cigarettes, cigars and the like. Tobacco sheet or strip material" made in accordance rwith our invention is elastic, flexible, tough, selfsupporting and continuous, and possesses-"dry andfwet strengthscomparable to that of. natural leavesor pieces of. tobacco, and retains substantially all naturalV characteristics and properties 0f tobacco, including color, aroma, and tastel on smoking. This is necessarily true since in our process, ther waste tobacco is merely dry ground, then deposited ontol the top surface ofv a film-forming material. Thus the principal portion of thev tobacco does not contact water or other foreign processing material, nor is its basic physical form (anatural, fibrous, somewhat porous, cellular structure) destroyed by the grinding or milling which is characteristic of previously suggested procedures. Therefore, this process unlike many that have been previouslyy proposed for utilization of waste tobacco materials, would allow the utilization of sucht tobacco materials vw'thout change from the natural. chemical condition in which they exist in-A normal smoking products. i This constitutes an important ad'- vantage of our process.

It is anobject of our invention toy provide an improved method of making novel reconstituted tobacco sheet or strip material. in which. a continuous wet web is formed from a film-forming material to which finely ground tobacco is applied so that the groundtobacco material adheres' to the film-forming. material in the wet web, and forms anintegral part of the web of reconstituted tobacco material produced. t

It is a further object of our invention to provide an improved method of making novel reconstituted tobacco sheet or strip material involving the formationiof a base layer of a film-forming materialf and` applying theretoan overlayer of a film-forming material, and while the latter is. in wet condition, applying, as by blowing, finely ground particles of tobacco to the top thereof, such that the ground tobacco particles adhere thereto, the resulting product having characteristics similar to those of natural tobacco.

The invention. also consists in.. the provision of an improved method of reconstituting tobaccoby forming a wet layer ofi a film-,forming material on a base web of similar film-forming material andv then applying; as by blowing, finely groundpal'ticles` Of tobacco to said wet web, after which the web is dried, treated as bybrushing, to remove excess tobacco, laminated and preferably treated by heated rollers to compact the outwardly projecting tobacco particles to forma porous, reconstituted tobacco sheet or strip material which can be. made into filaments byshredding, or cut into sheetsor strips-for use in making smoking articles such as cigarettes,I cigars and the like.

Withthese and other objects not specifically mentioned in view, the invention consists:` in certainy features which will be hereinafter fully described, and then set forth in the claims. hereunto appended.

In the accompanying drawings,l which form a part of this specification, and wherein the severalreferencel characters designate the same or like elements:

Figure 1 is a diagrammatic, schematic illustration disclosing the preferredmethod of performing the invention;

Figure 2 is a view showing diagrammatically a moditiedmethod of producing our novel reconstituted tobacco sheet material;v

Figure. 3;v illustrates a piece of the' laminatedy reconsttuted tobacco. producent byf our method;

Figure 4 is a sectional view, greatly enlarged, taken on line 4-4 ofFgure. 3;,

Figure 5 isy a c ross-sectionalA view, greatly enlarged, of. a modied typey of our` novel reconstituted tobacco sheet or strip material in which'. the tobacco-covered surfaces of the film. are.` adhered to each other;

Figure 6, is a view showing. a single thickness of our novel reconstituted Sheetv material;

Figure. 7 is a diagrammatic,V cross-.sectional view of av highly magnified piece of; our novel` reconstituted tobacco material'not heat-pressed; and

Figure 8 is a view, similar' to Figure 7, showing the material after being heat-pressed.

Referring to the drawings, in Figure l, which shows diagrammatically the steps covering the preferred method of our invention, 2 designates the step of preparing a dispersion or solution of a film-forming material used in making the base web of our'reconstituted tobacco sheet. Any film-forming material can be used which possesses adequate strength, retains the tobacco particles well, and which, on'smoking the final reconstituted tobacco film, does not cause an unsatisfactory taste, aroma or harshness in the smoke. Stated otherwise, the ilmforming material used does not introduce disagreeable flavors or aromas into tobacco smoke. Hence its presence is not objectionable to smokers or users of the product. Suitable film-forming materials are soluble salts of carboxymethylcellulose and carboxymethyl hydroxyethyl cellulose, or carboxymethylcellulose and carboxyrnethyl hydroxyethyl cellulose, the latter two being insoluble in water, but, as described hereinafter, capable of being formed into stable water dispersions in the manner described in a copending application tiled by Newton Heimbach on December 21, 1949, for Water Insoluble Coatings, Films and Adhesives and Method of Making Same, Serial No. 130,858. These dispersions are capable of being cast to form a wet web which when dried, becomes a self-supporting film. The terms carboxymethylcellulose and carboxymethyl hydroxyethyl cellulose where used herein, mean the free acid form of these compounds.

While the strength of films formed from the abovementioned types of dispersions or solutions is high, it is preferred to add a small quantity of an inert and tasteless filler to the dispersion or solution before forming into the wet web or filament to increase the tensile strength of the product (as indicated at 4 in Figure l). Materials such as kaolin and fullers earth have produced satisfactory results. Finely ground Vtobacco waste may also be used for this same purpose. Also, strengthening and/or waterproofing materials, such as glyoxal, which presumably react with the film-forming constituent to modify the type of intermolecular or intermicellar linkages, can be added, if desired, to the above-mentioned solutions and dispersions. When a filler and/or additive is used, it is mixed with the film-forming solution or dispersion, after which the dispersion is converted in any suitable manner as by coating or spraying upon a lmforming surface, into a continuous layer or wet web and dried as desired to form continuous self-supporting dry sheets or strips, as the case may be.

As indicated in Figure 1, the film-forming dispersion or solution is applied, as by spraying, by a suitable device 6 upon the surface of an endless traveling beltS to form a continuous wet web, which in the preferred method, is termed the base web B. If desired, small sized individual sheets can be cast directly at spaced intervals on belt 8 or on flat plates (not shown). Belt 8, or plates (not shown) upon which film B is cast or formed in any other suitablemanner, are bestmade of a material which will not react noticeably with the film-forming material to cause discolorations, spots or marks. Suitable materials for this purpose are stainless steel, or chromium-plated belts or at endless bands, or iiat plates of the same materials or'similarly `treated materials. v

Belt 8 runs on driven and driving pulleys 10, i2, preferably continuously driven in order that the web may be moved by the upper lap of the conveyor belt past the several stations necessary to complete the operations of the method. AFollowing the casting of base web B on belt 8, the moving belt carries the wet base web B through a drying station indicated generally, at 11, after which an overlayer O is applied to the upper surface of the base web B. While it is desirable to dry base web B before Y 4 the application of overlayer O thereto, this step may be omitted and satisfactory results will be obtained.

Overlayer O is prepared in the same general manner as base web B. That is, an aqueous solution of sodium carboxymethylcellulose or aqueous dispersion of carboxymethylcellulose, or other suitable film-forming, adhesive material, which will bond to both the base web and thc tobacco particles, is prepared, as at 14, and applied by a suitable applying device 16 to base web B. lf desired, a filler such as kaolin can be admixed as at 18 with thc overlayer adhesive solution or dispersion prior to its application to the surface of base layer B. Also, strengthening and/0r waterproofing materials, such as glyoxal, which presumably react with the film-forming constituent to modify the type of intermolecular or intermicellar linkages, can be added, if desired, to the above-mentioned solutions and dispersions. The base layer B and overlayer O are substantially equal in width and extend approximately to the longitudinal edges of endless band 8, although obviously the web width can be varied as desired. It is usually preferred that the solution or dispersion used in forming overlayer O be less viscous than that used in making base web B. lt is advantageous to make the base web of high concentration to minimize the amount of drying required at 11 and advantageous to make the overlayer comparatively uid to obtain maximum strength of bond between the tobacco particles and the film-forming base web.

It has been found that satisfactory reconstituted tobacco sheet or web material, made in accordance with our int vention, is formed when the base web and overlayer web are formed of a solution of sodium carboxymethylcellulose, or an aqueous dispersion of carboxymethylcellulosc. A satisfactory product is also produced when the base web is made of a solution of a soluble carboxymethylcellulosc salt and the overlayer web is formed from an aqueous dispersion of carboxymethylcellulose, or vice versa. It is, however, preferred to use carboxymethylcellulose for both layers B and O because the nal product then exhibits greater resistance to the steam and moisture used in casing tobacco in the tobacco factory and to the saliva in the smokers mouth.

Following the application of overlayer O to base web B', the wet composite web on conveyor 8 moves to a tobacco dust applying station 20, where mechanism of suitable design applies tobacco dust to the entire surface of the wet web moving therethrough. The term dust as used herein is intended to mean ground or nely divided tobacco. It may be formed from tobacco of any suitable type, as for instance, whole leaves or portions thereof, stems, or waste tobacco including field scrap, or clippings, dust, siftings and chips resulting from the manufacture of cigarettes, cigars and other tobacco products, or from whole tobacco plants including stalks and whole leaves attached thereto. In preparing this dust, it is believed preferable to separate and remove foreign material such as sand and dirt which oftentimes is mixed with tobacco. The latter is then dry ground to a suitable particle size. We have found that satisfactory results are obtained when the particles are 7 microns minimum size, 600 microns maximum size, and average between 10U-150 microns, although this is not critical, and depends upon the characteristics desired in the finished product.

A suitable device for applying tobacco dust to the surface of web O is a blower connected by a conduit to a nozzle, the latter being moved back and forth across the moving wet web O as the air blast forces tobacco dust from the nozzle into adhering relationship with the web, whereby substantial quantities of dust adhere thereto.

In the application of tobacco dust to the wet composite web consisting of base film B and overlayer film O, an excess of dust is usually applied, as by blowing at overlayer O, in order that wet overlayer film O will be thoroughly coated;

The `quantity of tobacco dust per unit area of product angelo V"l" ing because of excessive distillation. and incompletefcombustion resulting from its lack of porosity.

In Figure 5, a modified type of sheet or strip material L is shown in which the tobacco-coated surfaces of the reconstituted sheet, web or lm material are treated with a small quantity of suitable adhesive A, such as the material used in making webs B vand O, and .then brought into juxtaposition and pressed, as .described above, into adhering relationship. This gives a stronger product having smooth surfaces. It is sometimes helpful to dust the exposed surfaces of the so laminated sheet with talc or tobacco dust or other suitable ymaterial to prevent blocking (sticking together `underpreSSure).

After being laminated, sheet or strip material L is moved to a dryer where the moisturecontent is reduced to any desired figure, e. g. `12%. At times it may then be advantageous to again brush. the sheet to remove loosely adhering tobacco particles. `The sheet or strip material L is then moved to a cutting device consisting of a rotating blade 3S and ledger blade 40, which cuts sheet or strip material L into desired lengths. If desired, however, laminated sheet or strip material L may be rolled into a reel (not shown), or it can be shredded by any suitable shredding device, such for: example as that indicated in Rundell Patent 2,184,567 issued December 26, 1939.

Examples of typical film-forming solutions and dispersions are given as follows:

EXAMPLE 1 Sodium carbaxymethylcellulose solution Composition of base web: Percent byvweight EXAMPLE 2 Sodium carboxymethylcellulose solution Y Composition of overlayer: Percent by weight Sodium carboxymethylcellulose (high vscosity) -v.. ..v.. 1.0 Kaolin 0.5 Glycerine l 1.0 Water 97.5

We have found that satisfactory results are obtained using high viscosity sodium carboxymethylcellulose (sodium cellulose glycolate)` in concentrations between 1 and 8% by weight in water. In the case of thefoverlayer web, the concentration is usually lower, than 8%.by weight. Obviously low viscosity and medium viscosity sodium carboxymethylcellulose (sodium cellulose glycolate) in suitable concentrations may be used if desired but give less advantageous results.

In the above examples, the constituents are added in any order and mixed thoroughly. If kaolin is' added, it is necessary to use a colloid mill orother known type of dispersing apparatus to disperse the kaolin uniformly.

As noted above, and in all other examples, it is preferrred to use a humectant and/or yplasticizer such as glycerine which tends to prevent the-tinalfreconstituted tobacco sheet or web material from becoming too dry and brittle. In the examples given herein, the'sodium salt of carboxymethylcellulose is used. However, if desired, other soluble carboxymethylcellulose` salts, such as the potassium and ammonium salts, can be used.

EXAMPLES 3' AND 1' Acid carboxymethylcellulose dispersions Percentages of materials used are the same asin Examples 1 and 2, exceptthat carboxymethylcellulose (cellu losevglycolic acid) is used as the film forming ingredient instead of sodium carboxymethycellulose.

Typical dispersions can be prepared as follows: A 1/10 inch diameter stream of a 3.75 per cent high viscosity sodium carboxymethylcellulose solution in water is extruded into about twice its weigth of 20 per cent sulfuric acid. The sodium carboxymethylcellulose solution forms threads which are allowed to stand in the acid two hours to complete the acidification of the sodium carboxymethlcellulose. The threads of reacted carboxymethylcellulose are then removed from the acid by means of a suitable screen. The insoluble carboxymethylcellulose is then washed with a stream of water until the pH of a dispersion formed by processing a sample of the carboxymethylcellulose threads in a Waring blender is 2.4. At, this point, the washing may be discontinued. The carboxymethylcellulose, which is now in the form of semi-solid, long, gelatinous strands, is then ground in a colloid mill, Waring blender, or similar device to produce a fine dispersion of carboxymethylcellulose in water.

The following conditions have been used to produce a satisfactory carboxymethylcellulose dispersion:

Exugiple Exanple Conditions To make a dispersion suitable for casting, the concentrated carboxymethylcellulose, prepared as described above, may be diluted to the desired concentration by the addition of water, the desired quantities of kaolin and glycerine added, and if desired, glyoxal may also be added, and the mixture dispersed in a colloid mill or other suitable device.

In forming satisfactory aqueous carboxymethylcellulose dispersions, it is found that good results are obtained when the concentration of the sodium salt of carboxymethylcellulose solution ranges between 2 and 8% by weight, and the final sulfuric acid concentration is be tween 5 and 25%. The time of acidification may vary over wide limits, as may the washing time. The pH of the final carboxymethylcellulose dispersion may also vary from about 1.5 to 5.0. Satisfactory results have been obtained using kaolin between 0 and 8% by weight, and glycerine ranging between 0 and 10% by weight based on the total weight of dispersion. When glyoxal is used, good results are obtained when the weight of glyoxal is between 0 and 20% of the weight of soluble cellulose glycolate salt or cellulose glycolic acid contained in the solution or dispersion.

The techniques described hereinabove for forming aqueous dispersions of cellulose glycolic acid are following in making aqueous dispersions of carboxy/methyl Y hydroxyethyl cellulose which for our purpose has' characteristics similar to those of cellulose glycolic acid. A satisfactory dispersion of acid carboxymethyl hydroxyethyl cellulose for use in forming sheet or strip material was made as follows:

EXAMPLE 5 permitted to stand inthe acid for two hours. The

aas-4,5m

hardened spaghetti-like. threads of the4 insoluble acidv form of carboxymethyl hydroxyethyl cellulose were removed from the acid, drained and washed. with runningwater for twenty minutes. The; washed threads were then dis,- persed in a manner similar to that described in Examples 3 and 4 to form an aqueous dispersion which was formed into a wet web which was. coated with tobacco dust and driedv to form a continuous reconstituted tobacco sheet and strip material.

In forming the webs decribed hereinabove, the solu.- tions or dispersions can be applied to belt 8 by spraying, spreading with a casting knife, such asA that described' in co-pending Jurgensen and Hungerford application, Serial No. 49,968, filed September 1.8, 1948, for Film Casting Knife and Process, now U. S. Patent 2,546,342, issued March 27, 1951, or by other known web or film-forming devices. The amount of dispersion generally applied or cast upon belt 8 depends upon the strength desired in. the final product, and the concentration and the composition of the dispersion. The quantity of ilmfforming material in overlayer O must be` sufficient to secure the tobacco to the base web, and the thickness of web B must be sufficient to provide the strength desired. Y

Typical examples of base web, overlay and, tobacco quantities are as follows:

EXAMPLE 6 Base web material Example l. Thickness of base web (wet) in l-/lQGO inch: 8'. Overlay material Example 2.

Figures 3 and 4 illustrate pieces or sheets of laminated reconstituted tobacco sheet or strip' material L produced by our method. In Figures 3 and 4, and also in Figures 5 to 8 inclusive, T designates the tobacco dust andv fine particles, and F indicates they tobacco-loaded continuous supporting film.

Figure 2 disclosesA amodified' method which is generally similar to the method disclosed in` Figure: l, except that it omits the formation of an overlayer web. AnsV disclosed in Figure 2, any suitable film-forming dispersion or solution is prepared. This may be made from a watersoluble salt or carboxymethyljcellulose or from carboxymetliylcellulose in the manner described above in connection with the preferred method illustrated in Figure 1. To the prepared film-forming dispersion or solution is added', as at 46, a quantity of filler suchl as kaolin or fullers earth which, as described above, increases thev tensilestrength of the film. Also, other strengthening and/or water-proofing additives suchas glyoxal may beA used). While the f addition of a filler is desirable, it can be omitted since it is not essential to thel production of a satisfactory reconstituted tobacco sheet material. After the filler' has been admixed with the prepared film-forming dispersion or solution, the latter is formed into a Wet web as at 48 on an endless conveyor belt S' inthe mannerl disclosed in Fig ure l. An excess of tobacco dustv is appliedv at 20 to the surface of the wet web a-nd'vmoisturey is then removed therefrom by means of a suitable drying' device indicated at 22. Following this operation, loosely adhering tobacco dust is removed by means of a' suitable device designated 24. The resulting sheet or strip material W is then mois'- tened as at 3i), removed froml conveyor` 8 by a doctor blade 32, laminated as at 36, dried andf then shredded or cut for packaging or manufactureI into smoking articles as indicated at 52. In some cases, it maybe desira-ble to again subject the laminated sheet or strip-material'to-the action of a brushing or dusteremoving device such as 54 after the removal of' the laminatedlshee-t on'stri'p: material from conveyor 8V andA drying if for any reason" tobacco l0 particles have: been: loosened from the sheet or strip. This operation is not: necessary, but. im some. cases, has proven desirable., As noted above, single layer'sheets can` be produced by omittingl the step: rnlamination.Y If desired, the product may be pressed, as disclosed above.

If desired, in the methods described above', tobacco dust can be applied to the undersurface (film side.) of the ref constituted' tobacco sheet or strip material W upon its: removal from conveyor belt 8. Ifv this is done, the underside of sheet or strip material W is moistened or coated with an adhesive, such as a light spray of the overlayer composition such as described in Example 2V or 4`. An excess of tobacco dust is then applied to the: wetv undersurface of sheet or strip material W. The composite sheet or strip material resulting therefrom is then dried,- excess tobacco is removed and a reconstituted tobacco sheet material or strip material designated W1 having a tobacco coating on both sides, such as shown` in. Figure 6,. is produced. Sheet or strip material W1, if desired, can. be pressed to compact the projecting` tobacco particles: and produce a sheet or strip having the. general appearance of the sheet shown in Figure 8, except that itV contains but a single layer of film-forming material.

If desired, narrow reconstituted tobacco filaments can be made by applying the above-described film-forming'dis.- persions to the surface of endless travelingl conveyor 8 by suitable casting or extruding mechanism, which can be similar to that disclosed in Wells et al., Patent. 2,433,877, issued January 6, 1948, after which the filaments are coated with tobacco in the same manner as the webs. or films formed in accordance withV the methods disclosed in Figures 1 and 2.

While preferred embodiments of the invention have been shown and described,y it is to be understood that the invention is not confnedto thespecic method steps and the details of construction of the apparatus for carrying out the methods herein set forth, byway of illustration, as it is apparent that many changes and variations maybe made therein', by those skilled in the art, without departing from the spirit of the invention, or exceeding, the scope of the appended claims.

What is claimed is;

l. Tobacco sheet material comprising an. initially water insoluble water dispersed adhesive material and finely dif vided tobacco the principal portion of which is dry ground when associated with said adhesive material.

2. Tobacco sheet material comprisingga water insoluble layer of film forming material and a coating of finely divided tobacco coveringv and adhering to they surface .of said layer in excess of live times the weight of said film forming material on a dry basis per unit area.

3. Tobacco sheet material comprising a water insoluble layer of filmv forming material and aV coating of finely divided tobacco covering` and adhering to the surface of said layer in excess of two and less than twenty times the weight of saidy film forming material on a dry basis per unit area. l

4. Tobacco sheet material comprising` a water insoluble layer of film forming material and a coating, of finely divided tobaccoadhering toi one surface or side ofsaid layer of filmV forming material in excess of two and less than Itwenty times the weight of said layer of film forming material on a dry basis per unit area.

5, Tobacco sheet material comprising a water insoluble layer of film forming material and a coating4 of finely divided tobacco adheringA to both surfacesor sides of said layer of film forming material in excess of two and less than twenty times. the weight of said layer'of film forming material on av dry basis per unit area.

6,. TobaccoV sheet material comprising a tobacco free layer of iilm forming material and a coating of finely divided tobacco. covering adhering to the surface of said layer in excess of five times the weight o f said film forming material on adry basis per unit area.

7. Tobacco sheet matcrialcomprising a tobaccofree 11 layer of fihn forming material and a coating of finely divided tobacco covering and adhering to the surface of said layer in excess of two and less than twenty times the weight of said film forming material on a dry basis per unit area.

8. Tobacco sheet material comprising a tobacco free layer of film forming material and a coating of finely divided tobacco adhering to one surface or side of said layer of film forming material in excess of two and less than twenty times the weight of said layer of film forming material on a dry basis per unit area.

9. Tobacco sheet material comprising a tobacco free layer of film forming material and a coating of finely divided tobacco adhering to both surfaces or sides of said layer of film forming material in excess of two and less than twenty times the weight of said layer of film forming material on a dry basis per unit area.

l0. Tobacco sheet material comprising a base web of tobacco free film forming material selected from the class consisting of cellulose glycolic acid, water soluble salts of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, and water soluble salts of carboxymethyl hydroxyethyl cellulose, an overlayer of a similar material covering the surface of said base web and forming therewith a composite web, and finely divided tobacco covering and adhering to said overlayer of said web.

11. Tobacco sheet material comprising a continuous self supporting web containing a film forming material selected from the class consisting of cellulose glycolic acid, water soluble salts of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose and water soluble salts of carboxymethyl hydroxyethyl cellulose, and tobacco dust covering and intimately adhering to the surface of said film in excess of five times the weight of said film forming material on a dry basis per unit area.

12. Tobacco sheet material comprising a continuous self supporting web containing a film forming material selected from the class consisting of cellulose glycolic acid, water soluble salts of cellulose glycolic acid, carboxyrnethyl hydroxyethyl cellulosey and water soluble salts of carboxy/methyl hydroxyethyl cellulose, and tobacco dust covering and intimately adhering to the surface of said film in excess of two and less than twenty times the weight of said film forming material on a dry basis per unit area.

13. Tobacco sheet material comprising a film of cellulose derivative film forming material selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, and tobacco dust covering and adhering to both surfaces of said film in excess of five times the weight of said film on a dry basis per unit area.

14. Tobacco sheet material comprising a film of cellulose derivative film forming material selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, and tobacco dust covering and adhering to both surfaces of said film in excess of two and less than twenty times the weight of said film on a dry basis per unit area.

l5. Tobacco sheet material comprising two continuous tobacco free webs of film forming material adhered together, said film forming material being selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, and a coating of finely divided tobacco over the outer surface of each of said webs.

16. Tobacco sheet material comprising a web of film forming material selected from the class consisting of cellulose glycolic acid, water soluble salts of cellulose` glycolic acid, carboxymethyl hydroxyethyl cellulose and water soluble salts of carboxymethyl hydroxyethyl cellulose, an overlayer web of said forming material adhering to said base web and a substantially uniform coating of tobacco dust adhering to the surface of said overlayer web.

17. Tobacco sheet material comprising a composite sheet including a layer of tobacco free material selected from the group consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, and a layer of finely divided tobacco adhering to the surface of said tobacco free material.

18. Tobacco sheet material comprising a composite film consisting of cellulose glycolic acid and substantially uniformly distributed finely divided tobacco adhering to said film and forming an integral part thereof.

19. Tobacco sheet material comprising a composite sheet consisting of a thin substantially water insoluble film of carboxymethyl hydroxyethyl cellulose, and finely divided tobacco particles adhering to and substantially uniformly covering the surface of said film.

20. Tobacco sheet material comprising a film of carboxymethyl cellulose, and tobacco dust in a quantity at least five times the weight of said film of carboxymethyl cellulose per unit area, the tobacco dust constituting a covering adhering to said film. 21. Tobacco sheet material comprising a film of carboxymethyl cellulose, and tobacco dust in a quantity at least two and less than twenty times the weight of said film of carboxymethyl cellulose per unit area, the tobacco dust constituting a covering adhering to said film.

22. Tobacco sheet material comprising two continuous lengths 4of film consisting of carboxymethyl cellulose, each of said lengths of film having a coating of tobacco dust substantially uniformly covering one surface thereof, the uncoated surfaces of said films being adhered together and forming a laminated web construction.

23. Tobacco sheet material comprising a continuous tobacco free film of a water soluble salt of cellulose glycolic acid and a coating of finely dvided tobacco covering the surface of said film and adhering thereto.

24. Tobacco sheet material comprising a continuous tobacco free film of a water soluble salt of carboxymethyl hydroxyethyl cellulose and a coating of finely divided tobacco covering the surface of said film and adhering thereto.

25. A method of forming tobacco sheet material which t comprises contacting an initially water insoluble adhesive material dispersed in water with finely divided tobacco the principal portion of which is dry ground.

26. The method of making tobacco sheet material comprising preparing a dispersion of a film forming material which becomes substantially water insoluble when dry, adding `a small quantity of a film strengthening filler to said dispersion, converting said dispersion into a thin continuous base web, preparing an overlayer dispersion from a similar film forming material which becomes substantially water insoluble when dry, adding a small quantity of a humectant to said overlayer dispersion, applyinga thin coating of said overlayer dispersion upon the surface of said base web in permanently adhering rclationship therewith to produce a composite web structure having a wet adhesive surface, heavily loading said wel surface with tobacco dust particles, drying said tobacco loaded web, removing loose tobacco from said tobacco dust loaded web, and forming said resulting tobacco web material into sheets of desired lengths and widths.

27. The method of making tobacco sheet material comprising forming a thin continuous adhesive web having a wet adhesive surface, applying tobacco dust substantially uniformly upon said surface yof said web while adhesive to form a composite heavily loaded tobacco coated web drying said heavily loaded web, brushing loose tobacco from said composite tobacco dust coated web, ap

lf3 plying an adhesive tothe tobacco coated surface of said tobacco web, bringing' lengths of said web-having adhesive tobacco coated surfacesI into contacting engagement, and pressing said lengths together to tormy tobacco sheet material.

28. The method of makingv tobacco sheet material comprising forming an aqueous dispersion of adhesive film forming material into a thin wet adhesive film having an adhesive surface when said film is wet, said film being substantially water insoluble when dry, applying a heavy coatingof finely divided tobacco to said wet ads hesive film to form a tobacco loaded webA and to adhere to said film a quantity ot" tobaccoA in an amount in excess of five times the weight of said film on a dry basis per unit area, and drying said web to form substantially water insoluble tobacco sheet materiali.

29. The method of making tobacco sheet material comprising forming an aqueous dispersion of adhesive film forming material intoV a thi'nrwet adhesive film having an adhesive surface when said film is wet, said film being substantiallyy Water insoluble when dry, applying a heavy' coating of finely divided tobacco to said wet adhesive film to form a tobacco loaded web and to adhere to said film a quantity of tobacco in an amount i'n excess of twov and less than twenty times the weight of sai'd film on a dry basis per unit area, and dryingsaid Web to form substantially water insoluble tobacco sheet material.

30. The method of making,k tobacco sheet material comprising forming a viscous aqueous film forming dispersion containing an adhesive, film forming material, which becomes substantially. water insoluble when dry, into a thin base Web having an exposed wet adhesive surface, coating saidV wet adhesive surface with. finely divided tobacco to form a composite tobacco sheetv material and drying said sheet material to render it substantially water insoluble.

311. The method of forming tobacco` sheet material which comprises applying to the surface of a non. fibrous layer of wet film forming material alayer of finelydivided tobacco to form a composite lamellar sheet and drying said sheet to adherea weight of said tobacco in excess of five times the weight of said film forming material on a dry basis per unit area.

32'. The method of forming tobaccor sheet material which comprises applying to the surface o'a non.' fibrous layer of wet film forming material a layer of finely divided tobacco to form a composite lamellar sheet and dryingl said sheet to adhere a weight of' said tobacco in excess of two and less than.. twenty times the weight of said film forming material on a. dry basis per unit area.

33. The method of making tobacco sheet materiali comprising forming from an adhesive tobacco free film forming material selected from the class consisting of cellulose glycolic acid, carboxymethylv hydroxyethyl cellulose, water soluble salts of cellulose. glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, a thin continuous composite web having an adhesive surface, applying tobacco dust substantially uniformly upon said adhesive surface of said web and' in excess of the amount of tobacco dust required to cover and to load said surface of said web, drying said tobacco coated composite web, and forming said resulting tobacco material into sheets.

34. The method of making tobacco.` sheet material comprising forming fromy a compound selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acidk and water soluble salts, of carboxymethyl hydroxyethyl cellulose, a thin continuous tobaccoy free base web, applying anv overlayerv of film formingv material selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic. acid and water .soluble salts of carboxymethyl hydroxyethyl. cellulose, to said base web to form 4a ycomposite web having an exposed wet surface, coating said exposed wet surface with tobacco particles to form a composite film, drying said tobacco coated composite film, moisening the uncoated faces of two. sections of said tobacco coated film with, an aqueous medium containing a film formingV material selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, and assembling said sections with said moistened faces in contacting engage ment to form laminated tobacco sheet material.

35. The method of producing tobacco sheet material comprising forming a thin, continuous tobacco free base web on a film forming surface from a film forming material selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, drying said web, applying an overlayer of a film forming material selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and' water soluble salts of carboxymethyl hydroxyethyl cellulose, over the surface of said base web, said overlayer adhering to and forming with said base web a thin composite web structure, heavily coating only one surface of saidV overlayer while wet with tobacco particles, drying said tobacco. coated web, and laminating lengths of said composite tobacco web with the surfaces not coated with tobacco in face to face relation to form tobacco. sheet material.

36. The method of producing tobacco sheet material comprising forming from an adhesive film forming material selected from the group consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, a thin, continuous tobacco free film on a film forming surface, applying to said film on said film forming surface while said film forming material is wet and adhesive, a loading in excess of five times the weight of said film in dry condition of finely divided tobacco, drying said tobacco coated film whereby said film forming material becomes substantially Water insoluble and said tobacco coating becomes adhered to said lm forming material, increasing the moisture content of said tobacco loaded film and removing said tobacco loaded film from said surface to form tobacco sheet material;

37. Thel method of producing tobacco sheet, material comprising forming from an adhesive film forming material selected from thev group consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose, water soluble salts of cellulose glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, a thin, continuous tobacco free. film on a film forming surface, applying to said film on said film forming surface while said lm forming material is wet and adhesive, a loading in excess of two and less than twenty times the weight of said film in dry condition of finely divided tobacco, drying said tobacco coated film whereby said l'm forming material becomes substantially water insoluble and said tobacco coating becomes adhered to saidy film forming material, increasing the moisture content of saidtobacco loaded film and removing said tobacco loaded film from said surface to form tobacco sheetV material.

38. The method of` producing tobacco sheet material comprising preparing a viscousadhesive film forming material selected from the class consisting of cellulose glycolic acid, carboxymethyl hydroxyethyl' cellulose, water soluble salts of cellulosev glycolic acid and water soluble salts of carboxymethyl hydroxyethyl cellulose, converting said film forming material into a thin, continuous base web, preparing anA overlay from*` a similar less viscous adhesive film formingl material, applying a thincoating of said overlay over a surface o f said b ase web to produce a. composite, web; struetureyhaving. anl adhesveg. surface;

` I and coating said adhesive surface of said overlay while wet with finely ground tobacco particles to form tobacco sheet material.

39. The method of forming tobacco sheet material, comprising forming a thin, continuous tobacco free web from a film forming material selected from the class consisting of cellulose glycolic acid, water soluble salts of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose and water soluble salts of carboxyrnethyl hydroxyethyl cellulose, then applying a coating of finely divided tobacco to one of the surfaces of said web while it is wet to form a tobacco coated web, drying said coated web, applying to the uncoated surface of said web an adhesive material selected from the class consisting of cellulose glycolic acid, water soluble salts of cellulose glycolic acid, carboxymethyl hydroxyethyl cellulose and water soluble salts of carboxymethyl hydroxyethyl cellulose to render said uncoated surface adhesive, applying a coating of finely divided tobacco to the adhesive uncoated surface of said web and drying said resulting tobacco sheet material.

40. The method of forming tobacco sheet material which comprises applying to the surface of a wet adhesive layer of cellulose glycolic acid, a layer of finely divided tobacco to form a composite lamellar sheet and drying said sheet to form tobacco sheet material.

41. The method of making tobacco sheet material comprising forming an aqueous dispersion of cellulose glycolic acid, casting said` dispersion into an endless film on an endless traveling surface, coating said film on said surface with a dispersion of cellulose glycolic acid to provide said film ywith a wet adhesive overlayer, applying tobacco dust substantially uniformly over said wet overlayer in an amount sufficient to heavily load said film, drying said dust loaded film, removing substantially all loose tobacco dust from said tobacco loaded film and removing said film from said traveling film forming surface.

42. The method of producing tobacco sheet material comprising preparing an aqueous film forming dispersion of cellulose glycolic acid film forming material, adding a relatively small quantity of a filler material to a first portion of said dispersion to increase the tensile strength of the film produced therefrom, continuously forming said first portion of said dispersion on a substantially impermeable film forming surface into a thin, endless, water insoluble web, continuously applying the remainder of said dispersion as an overlayer of an aqueous insoluble film forming dispersion over the entire surface of said first portion of dispersion in permanently adhering relationship therewith to form a composite continuous web having an exposed wet surface, coating said exposed wet surface with finely divided tobacco particles in excess of five times the weight of said web on a dry basis per unit area, diying said heavily tobacco loaded composite continuous web whereby said web becomes water insoluble, brushing loose tobacco particles from said tobacco coated surface of said tobacco coated web, moistening said brushed tobacco coated composite web and removing it from said film forming surface, and then drying said web to form tobacco sheet material.

43. The method of producing tobacco `sheet material comprising preparing an aqueous film forming dispersion of cellulose glycolic acid film forming material, adding a relatively small quantity of a filler material to a first portion of said dispersion to increase the tensile strength of the film produced therefrom, continuously forming said first portion of said dispersion on a substantially impermeable film forming surface into a thin, endless, water insoluble web, continuously applying the remainder of said dispersion as an overlayer of an aqueous insoluble film forming dispersion over the entire surface of said first portion of dispersion in permanently adhering relationship therewith to form a composite continuous web having an exposed wet surface, coating said exposed wet surface with finely divided tobacco particles in excess of two and less than twenty times the weight of said web on a dry basis per unit area, drying said heavily tobacco loaded composite continuous web whereby said web becomes water insoluble, brushing loose tobacco particles from said tobacco coated surface of said tobacco coated web, moistening said brushed tobacco coated composite web and removing it from said film forming surface, and then drying said web to form tobacco sheet material.

44. The method of forming tobacco sheet material comprising forming a tobacco free film forming composition of a soluble salt of cellulose glycolic acid, casting said composition on an endless traveling surface into a continuous wet web, applying tobacco dust substantially uniformly upon the wet web on said surface, said dust being applied in excess of the amount required to cover said surface of said web substantially uniformly, drying said dust loaded web, removing loose tobacco from said tobacco loaded web, moistening said web and removing said web from said travelingsurface, drying said web, and forming said resulting tobacco material into sheets.

45. The method of making tobacco sheet material comprising forming an aqueous dispersion of cellulose glycolic acid, casting said dispersion into a continuous web on an endless traveling surface, coating said web on said surface with a dispersion of cellulose glycolic acid to provide said web with a wet adhesive overlayer to form a composite cellulose glycolic acid film having a wet adhesive surface, said film when dry being substantially water insoluble, applying tobacco dust to said wet overlayer in an amount sufficient to cover substantially uniformly the overlayer surface of said web, drying said dust loaded web, removing substantially all loose tobacco dust from said loaded tobacco web, removing said web from said traveling film forming surface, the tobacco dust adhering to and intimately associated with said web being greatly in excess by weight of the weight of said web of cellulose glycolic acid per unit area, subjecting said tobacco sheet material thus produced to heat and pressure to position projecting tobacco particles in substantially contiguous relationship relative to the plane of said composite web, moistening with an adhesive material the tobacco free faces of lengths of said tobacco coated composite web, arranging said lengths with said moistened faces in contacting engagement, pressing said lengths together to form laminated tobacco sheet material, and then brushing said faces of said laminated tobacco sheet material to remove loose tobacco therefrom.

46. The method of forming tobacco sheet material comprising forming atobacco free film forming composition of a soluble salt of cellulose glycolic acid, casting said composition on an endless traveling surface into a wet continuousk web, applying tobacco dust substantially uniformly upon the wet web on said surface, said dust being applied in excess of the amount required to load said web substantially uniformly with a predetermined quantity of tobacco per unit area of said web, drying said dust loaded web, removing loose tobacco from said tobacco loaded web, moistening said web and removing said web from said traveling surface, drying said web, treating the uncoated surface of said tobacco material web to render it tacky, arranging lengths of said treated web with Said tacky surfaces in contacting engagement, and pressing said lengths together to form a laminated tobacco material web structure.

47. The method of making tobacco sheet material comprising forming a tobacco free film forming composition of a soluble salt of carboxymethyl hydroxyethyl cellulose, casting said composition on an endless traveling surface into a continuous web having a wet surface, applying tobacco dust upon' the wet surface of said web, said dust being applied in excess of the amount required to cover substantially uniformly said surface of said web, drying said dustvloaded web, removing loose tobacco from said tobacco. loaded web, moistening said tobacco Vloaded web to facilitate its removal from said endless 17 traveling surface and removing said loaded web from said surface.

48. The method of making tobacco sheet material com prising forming an aqueous stable dispersion of carboxymethyl hydroxyethyl cellulose, converting said dispersion into a thin continuous web, applying tobacco dust substantially uniformly over the surface of said web, drying said dust coated web and removing substantially all loose tobacco dust from said tobacco coated web.

49. The method of making tobacco sheet material comprising forming a tobacco free solution from a soluble salt of carboxyrnethyl cellulose, converting said solution into a thin continuous base web, preparing an overlayer from a similar film forming material, applying a thin coating of said overlayer over a surface of said base web to form a composite web structure having a wet adhesive surface, coating said web surface substantially uniformly with tobacco dust particles, drying said tobacco coated web and removing loose tobacco from said tobacco dust coated web to form said tobacco sheet material.

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