US3209763A - Method for making tobacco products - Google Patents

Description

Oct. 5, 1965 H. B. PARMELE ETAL 3,

METHOD FOR MAKING TOBACCO PRODUCTS Original Filed April 5, 1961 mm oM NM NM \N MNuQ s Q &

INVENTORS. HARRIS B. PARMELE,

FREDERICK J. SCHULTZ, CHASE W. LASSITER 8 JIMMY H. BELL BY their ATTORNEYS United States Patent 3,209,763 METHOD FOR MAKING TOBACCO PRGDUCTS Harris B. Parmele, Glen Ridge, N..l., and Frederick J.

Schultz, Chase W. Lassiter, and Jimmy H. Bell, Greensboro, N.C., assignors to P. Lorillard Company, New York, N.Y., a corporation of New Jersey Original application Apr. 5, 1961, Ser. No. 100,842, now Patent No. 3,166,078. Divided and this application Nov. 20, 1962, Ser. No. 245,343

5 Claims. (Cl. 131-140) This is a division of United States application Serial No. 100,842, filed April 5, 1961, now US. Patent No. 3,166,078.

This invention relates to methods for making tobacco products, and has particular reference to restoring waste tobacco into usable form especially adapted for mixture with, or as, chewing tobacco.

It is well known that during the stripping of leaf tobacco in preparation for its use for cigar wrappers or filler, cigarettes and smoking tobacco, a substantial quantity of stems and leaf scraps remains as waste although some of it has been used for making snuff and for mixture with chewing and smoking tobacco. In addition there is the tobacco scrap and dust resulting from shipping, handling and other causes. Inasmuch as this so-called waste is high grade, flavorful tobacco, numerous proposals for its economic use have been made, principally its conversion into the form of synthetic leaf or reconstituted tobacco made by adhesively binding finely ground tobacco and forming the mixture into sheets, ribbons or the like and substituting the same in Whole or in part for natural leaf in cigars, cigarettes, smoking tobacco and other tobacco products.

In addition to the problem of impairment of the tobacco flavor in the smoke from burning reconstituted tobacco caused by the adhesive binders used for uniting the fine tobacco particles into a reconstituted sheet, there are economic and other disadvantages resulting from this practice. For example, the commercial use of well-known pa per making techniques in manufacturing such reconstituted tobacco in sheet or ribbon form requires 24 hour, 7 day week operation in order to be economically feasible. Also, large volumes of water must be used to form the necessary screen slurry, with the result that many of the desirable constituents of the natural tobacco are leached out by and lost in the excess water that drains from the screen. After forming the rudimentary sheet on the screen, the water remaining therein must be evaporated, either by heat or prolonged air drying, which further removes some of the desirable volatile tobacco components, easily lost because of the large surface exposure of the fine tobacco particles. After drawing, the reconstituted sheet is relatively brittle and cannot be freely handled without loss in subsequent manufacturing operations and the product has little Water resistance without disintegrating and hence cannot be dipped in flavoring solutions such as are commonly added to smoking and chewing products.

In accordance with the present invention, reclaimed tobacco fines are united into a self-sustaining sheet or ribbon Without the use of substantial volumes of water or added heat, costly paper-making techniques and machinery, but instead by a simple method and apparatus to form a novel product which is especially adapted as and for mixture with chewing tobacco.

The invention comprises mixing finely-divided tobacco from any source with a tasteless and odorless thermoplastic resin having a relatively low softening point, working the mixture under such conditions that the friction between the tobacco particles and the resin and between each other generates sufficient heat to soften the resin so that the particles and resin flow together and may be formed into a sheet, ribbon or the like, which when 3,209,763 Patented Oct. 5, 1965 cooled to remove the heat of friction, results in a homogeneous body which is self-sustaining but sufliciently flexible to be readily handled and used without disintegration for formation into cakes or plugs, small sheets or flakes, sticks and the like for use as or in admixture with chewing tobacco.

More particularly, the invention comprises grinding to relatively uniform particle size Waste tobacco such as stems, leaf scraps, particles and dust resulting from leaf stripping, storage, manufacture and handling, then intimately mixing the ground tobacco with a water-insoluble resin, such as the polymeric vinyl ester type, preferably with a suitable plasticizer for the resin, and adding such sweetening and flavoring materials as may be desired for the finished product. The resin may be in the form of granules or an emulsion or solution thereof and may be mixed with the plasticizer before admixture with the tobacco, with the flavoring materials added during the tobacco-resin mixing operation. The resulting dry or substantially dry mixture is then worked under pressure by a milling operation between a series of rollers or by pressure extrusion through an extrusion press until the heat generated by the friction between the resin and the tobacco particles, and between each other, reaches or slight ly exceeds the softening point of the resin, whereupon the mixture becomes plastic and the particles flow together into a homogeneous mass which, when cooled to remove the auto-generated heat, results in a solid, self-sustaining flexible body of any desired form or shape, such as a sheet, ribbon, rod or the like.

Referring to the drawings:

FIGURE 1 illustrates semi-diagrammatically the novel apparatus whereby the method of this invention may be carried out to produce the product of this invention;

FIG. 2 is a cross-section through the apparatus of FIG. 1 as seen along the line 2-2 of FIG. 1, and

FIG. 3 is a semi-diagrammatic section through an extrusion apparatus whereby the method of this invention may be alternatively performed.

Referring to the drawings, and with particular reference to FIGS. 1 and 2, the admixture of at least 60% by weight of dry ground tobacco, at a fineness of 8 mesh per square inch or less, from any source, mixed with not more than 40% by weight of a water-insoluble thermoplastic binder, e.g., a granular polyvinyl acetate resin, is fed by gravity from a hopper 10 to a distributing slot as a layer 11 across a travelling steel belt 12, driven at slow speed, e.g., 10 feet per minute, by chain 13 from motor 14. The belt 12 carries the tobacco-resin mixture, levelled by fixed blade 15 to a thickness of about /8 inch, into the nip of two rollers 16, 17, driven at the same peripheral speed but in opposite directions by a chain 18 from motor 19 and a sprocket 20 and chain 21 from motor 14.

As the tobacco-resin mixture passes along with belt 12 into and between the nip of rollers 16 and 17, which may be knurled to increase the friction of their surfaces, the mixture is worked by a milling operation in the first stage. This milling operation involves considerable inter-particle mixing and consequent friction between the resin and the tobacco particles and between the resin particles and the tobacco particles. This pressure milling or working generates considerable frictional heat but not enough heat to soften the resin to the adhesion point, which in the case of polyvinyl acetate is about 92 C. However, sufficient bonding takes place to effect non-selfsupporting coherence, particularly when the rollers are closely-spaced. To that end, the rollers 16, 17 are fixedly but adjustably journalled in frame 26 so as to be spaced apart about 0.003 to 0.01 inch at the nip. Hence, the resin-tobacco layer is gradually compressed from about /a to as little as 0.003 inch as it enters the nip from between the flaring surfaces of the rollers 16, 17. As the result, the autogeneous heat 3 friction forms'the resin-tobacco mixture into the rudimentary sheet or ribbon S, which, being non-selfsustaining, requires support by the platform 27.

As it emerges from between the rollers 16, 17 the heat softened sheet or ribbon S expands to about double the nip thickness, i.e., about 0.006 to 0.02. inch, and also tends to stick somewhat to the rollers 16, 17 so that tangential doctor blades 28 adjustably mounted on frame 26 strip it from the surfaces of rollers 16, 17.

The expanded rudimentary sheet is pushed along platform 27 into the nip of a second set of rollers 22 and 23 journalled on frame 26 and also spaced apart about 0.003 to 0.01 inch at the nip and knurled if desired, driven at the same speed and direction as rollers 16, 17 by respective chains 18 and 21 meshing with corresponding sprockets 24, 25. Doctor blades 29 engage the surfaces of rollers 22, 23, also being adjustably mounted on the frame 26.

Further milling of the tobacco-resin mixture to secure the requisite homogeneity and the self-supporting properties may be desired for the sheet or ribbon S, which is at least partially unitarily bonded as it emerges onto platform 30 from between rollers 22, 23. Hence, a third set of milling rollers 31, 32, preferably spaced apart the same distance as are rollers 16, 17 and 22, 23, may be provided and are driven at the same surface speed as those preceding rollers by the respective chains 18 and 21, meshing with corresponding sprockets 33 and 34 fixed tothe shafts of rollers 31, 32.

The autogenously heated and bonded sheet or ribbon S emerging from between the third set of rollers 31, 32 is stripped therefrom by fixed doctor blades 35 and, expanding to a thickness of at least about 0.006 to 0.02 inch, is supported on platform 36.

Depending on the thermoplastic resin selected and upon the degree of self-sustaining strength and flexibility desired for the finished sheet, a fourth and even a fifth set of milling rollers may be desired. Considering the fourth set, rollers 37, 38 are preferably spaced apart 0.003 to 0.01 inch and driven at the same peripheral speed of preceding rollers 31, 32 by respective chains 18 and 21 as shown in FIG. 1. These rollers 37, 38 recompress the sheet or ribbon S entering their nip from platform 36 and consequently further mill and thus add more frictiongenerated heat thereto, so that greater strength and flexibility are added. Accordingly sheet or ribbon S emerges from between rollers 37, 38 and doctor blades 39 onto platform 40 in finished form, requiring only removal of the residual friction heat and that may be simply accomplished by cool air jets from header 41 extending over the sheet or ribbon S as it is carried from platform 40 onto and by belt 42 driven from chain 21, as shown in FIG. 1.

The finished continuous sheet or ribbon S carried by belt 42 preferably has an average thickness of about 0.01 inch and may be severed into short lengths S by an intermittently engaging rotating blade 43 driven from motor 19. The severed lengths S are collected in container 44 for formation into cakes, plugs, small sheets or flakes, sliced into narrow strips or the like, depending on requirements.

Where roller sets additional to the four sets shown in FIG. 1 are desired or required, it will be understood that they will be driven in the same way as the preceding roller sets.

The heat of friction for autogenously binding the finelydivided particles together with a thermoplastic resin such as the polymeric vinyl ester type may also be provided by extruding the tobacco-resin mixture under pressure through a progressively contracting tube in a known manner. However, it is preferred that the extrusion step follows the milling or working step afforded by at least the first set of rollers 16, 17 shown in FIG. 1, in order to obtain the desired homogeneity of mixing with some bonding provided by the initial heat of compression between the rollers. Thus, as shown semi-schematically in FIG. 3, the resin-tobacco sheet or ribbon S" emerging from between compression rollers 16, 17', onto platform 45 following doctor blades 46 enters the cylinder 47 of the extrusion press to be severed and compressed by reciprocating piston 48 driven by crank wheel 49. The piston 48 forces the severed sheet S into the converging funnel 50, where it is compressed with increasing friction-generated heat, which softens the resin still more to the point where it flows and bonds the tobacco particles together. The highly compressed and hot tobacco-resin mixture emerges from funnel 50 as a homogeneous self-sustaining rod or ribbon R, which may be severed into short lengths for admixture with chewing tobacco or used directly as chewing tobacco, depending on requirements.

As stated, the preferred binder is a resin of the polymeric vinyl ester type such as polyvinyl acetate derived from an acid containing only two carbon atoms. Resins of this type are preferred because they are not only waterinsoluble, thus precluding the finished product from becoming sticky or friable in moist atmosphere and enabling treatment by added flavoring compounds without damage, but also because such resins are odorless and tasteless, thus leaving available the full flavor of the tobacco without impairment of taste by the resin. However, because such res-ins burn with an odor considered by some to be unpleasant, the product of this invention has greatest utility in or as chewing tobaccos with or without sweetening or flavoring additives such as licorice, fruit extracts, molasses and sugar. The product is not appreciably attacked by cas-ing solutions or saliva, but will release the included tobacco and added flavoring materials in the same way and at the same rate as does the highest quality chewing tobacco. Although the product is best adapted for chewing purposes, small quantities thereof may be mixed with smoking pipe or cigarette tobacco without noticeably affecting the odor or taste of the latter.

The preferred polymeric vinyl ester resin is polyvinyl acetate, commercially known as Elvacet 81-3300 or Vinac B7 for example, or a mixture of polyvinyl acetate and polyethylenevinyl acetate, commercially known as Elvax or Elvax 250, for example. The physical properties of flexibility and toughness imparted by these resins to the finished product may be varied by choosing from the various commercial grades thereof with respect to molecular weight chain length or degree of cross-linking and branching. Thus, the higher molecular weight or more cross-linked material gives a tougher, less flexible product, whereas a resin of this type having a low molecular weight gives a more flexible and less tough product. The resin may be used as an emulsion with water, as a solution with an organic solvent such as ethanol or as a solid in the form of small beads or powder, all easily and equally usable. Where a resin solvent such as ethanol is preferred, the solvent evaporates quickly from the sheet or ribbon S between the compression stages and such evaporation is hastened by the heat of compression.

The preferred plasticizer is chosen from that group which has been government-approved for use as food additives, e.g., triacetin, and may be mixed with the resintobacco mixture before it is fed to the hopper 10. Flavoring compounds may be added before or after the hopper 10, as by dusting or spraying the same on initial layer 11.

Typical examples of methods of compounding the ingredients and the resulting products according to the invention are as follows:

Example I Two grams of triacetin were mixed well with 36 grams of a water emulsion of polyvinyl acetate containing 55% solids. After thorough mixing, this emulsion was added to 40 grams of powdered cigar leaf tobacco. The resulting mixture was thoroughly blended in a muller type mixer. Four grams of powdered sugar and 1 gram of powdered licorice were added and the blending continued for 20 minutes. It should be noted that the blending time is not critical and can be shortened to a small fraction of that mentioned here if it is so desired.

After the desired amount of blending the material was dried by suitable means, such as by use of a belt drier with infrared heaters, until the moisture content was of the order of to The dried material was then passed between several sets of mechanically driven rollers set with a spacing of 0.003 to 0.01 inch. The product emerged from the last rolling as a continuous ribbon with a thickness roughly twice the spacing between the last set of rolls.

Example ll Two grams of triacetin were added to 33.4 grams of a 60% solution of polyvinyl acetate in ethanol. This solution was well stirred into a mixture of 40 grams of cigar tobacco, 4 grams of powdered sugar and 1 gram of powdered licorice. Most of the ethanol was removed from this mix-ture by means of a belt drier. The resulting powder was then fed into a set of rollers with the spacing set as indicated in the previous example. The material from the first set of rollers was fed into a second set and so forth until a continuous ribbon was formed. In this instance, five sets of rollers were required.

It was not necessary to remove all of the ethanol in the drying operation since the remainder was driven off by the heat generated by the milling action of the rollers. This milling action also achieved the final blending of the plasticized resin with the other materials in the product.

As was the case in the previous example, the ribbon formed was approximately twice the thickness of the space between the rolls used in the final rolling.

Example Ill Two grams of triacetin were stirred into 20 grams of powdered polyvinyl acetate. The resulting moist powder was mixed with 40 grams of ground tobacco, 4 grams Example IV Ten parts of ground polyvinyl acetate were mixed with 10 parts of ground polyethylene vinyl acetate. This mixture was stirred with 1 part of triacetin and the resulting blend was mixed with 40 parts of tobacco dust. To this mixture was added, with stirring, 4 parts of powdered sugar, 1 part of powdered licorice and 1 part of black strap molasses.

The resulting powder was fed through four sets of rollers in succession with the spacing of each set adjusted so as to have a clearance of approximately 0.003 inch. The product emerged from the last set as a continuous ribbon with an average thickness of about 0.006 inch.

Liquid flavoring materials such as corn syrup, molasses, fruit extract and dry or solid flavoring materials such as powdered sugar and powdered licorice, etc., may be added to the above mentioned compositions in amounts up to 20% of the weight of the tobacco used, providing only that they are not volatile and are not decomposed by heat below 100 C.

Operation of the apparatus and conduct of the process of this invention will be evident from the foregoing description thereof, whereby there is and may be produced a new chewing tobacco product which, when chewed, re

leases the tobacco taste and flavor from the individual tobacco particles, which, because of their relatively small size, expose and present a large aggregate surface area for soluble cooperation with the saliva of the chewer. At the same time, the resin binder, being chewable, holds the tobacco particles together in and as a plastic mass, whose plasticity increases with the warmth of the chewers mouth but does not become fluid so as to lose its plastic coherence.

The sheets, ribbons or rods-may be further subdivided and mixed with chewing leaf or used alone: and after being formed into cakes or plugs, small sheets, flakes, or other desired forms or shapes may be marketed in the usual way.

Although certain preferred proportions of tobacco fines to binder and flavoring components have been specified in the foregoing examples, it is to be understood that the invention is not limited thereby or thereto, but is susceptible of changes in form and detail within the scope of the appended claims.

We claim:

1. The method of forming a chewing tobacco product, which comprises mixing tobacco particles with a waterinsoluble, odorless, tasteless thermoplastic binder having an adhesion temperature of less than C. and softenable to chewable plasticity at body temperature, compress ing said mixture by forcing the same in an unheated condition through a constricted space, to subject said mixture to pressure and friction to generate sufficient heat to soften said thermoplastic binder and unite the tobacco particles into a coherent non-self-sustaining rudimentary body and further forcing said rudimentary body through at least one other constricted space to generate sufficient heat to soften and render said binder adherent and unite said tobacco particles into a coherent self-sustaining body.

2. The method of forming a self-sustaining body composed principallly of tobacco as set forth in claim 1 in which said binder is a thermoplastic polymeric vinyl ester.

3. The method of forming a self-sustaining body composed principally of tobacco as set forth in claim 1 in which said binder is a thermoplastic polyethylene vinyl acetate.

4. The method of forming a self-sustaining body composed principally of tobacco as set forth. in claim 1 in which said binder comprises a mixture of a thermoplastic polyvinyl acetate and thermoplastic polyethylene vinyl acetate.

5. The method of forming a self-sustaining body composed principally of tobacco as set forth in claim 1 in which said thermoplastic binder is dissolved in a non aqueous solvent, and said solvent is evaporated by the heat generated by forcing said mixture through said constricted. spaces.

References Cited by the Examiner UNITED STATES PATENTS Re. 19,553 4/35 Pfohl 18-12 551,306 12/95 Converse et al. 18-12 1,643,059 9/27 De Both 264- 2,012,833 8/35 Smith 18-9 2,351,866 6/44 Miller 264-175 X 2,951,263 9/60 Cooper 264-175 X 3,012,562 12/61 Merritt 131-140 3,025,860 3/62 Grossteinbeck et al. 131-140 3,098,492 7/63 Wurzburg et a1 131-17 X ABRAHAM G. STONE, Primary Examiner. P. RAY CHAPPELL, Examiner.

Claims (1)

1. THE METHOD OF FORMING A CHEWING TOBACCO PRODUCT, WHICH COMPRISES MIXING TOBACCO PARTICLES WITH A WATERINSOLUBLE, ODORLESS, TASTELESS THERMOPLASTIC BINDER HAVING AN ADHESION TEMPERATURE OF LESS THAN 100*C. AND SOFTENABLE TO CHEWABLE PLASTICITY AT BODY TEMPERATURE, COMPRESSING SAID MIXTURE BY FORCING THE SAME IN AN UNHEATED CONDITION THROUGH A CONSTRICTED SPACE, TO SUBJECT SAID MIXTURE TO PRESSURE AND FRICTION TO GENERATE SUFFICIENT HEAT TO SOFTEN SAID THERMOPLASTIC BINDER AND UNITE THE TOBACCO PARTICLES INTO A COHERENT NON-SELF-SUSTAINING RUDIMENTARY BODY AND FURTHER FORCING SAID RUDIMENTARY BODY THROUGH AT LEAST ONE OTHER CONSTRICTED SPACE TO GENERATE SUFFICIENT HEAT TO SOFTEN AND RENDER SAID BINDER ADHERENT AND UNITE SAID TOBACCO PARTICLES INTO A COHERENT SELF-SUSTAINING BODY.

Images