US3430634A - Method of making a reconstituted tobacco sheet having improved filling power - Google Patents

Description

March 4, 1969 w. P. SCHWEITZER ET AL 3,430,634

- METHOD OF MAKING A RECONSTITUTED TOBACCO SHEET HAVING IMPROVED FILLING POWER Filed April 14, 19s? li TTORNEYS United States Patent 2 Claims ABSTRACT OF THE DISCLOSURE A reconstituted tobacco sheet is formed, and while the sheet is wet and being carried by a rotating support roll, it is doctored off the roll to produce a crepe in the sheet. The dried, creped sheet may then be cut up to produce a filler material for cigarettes or cigars.

This invention relates to a process for making an improved reconstituted tobacco sheet.

The utility of any particular reconstituted tobacco depends to a considerable degree upon the extent to which shreds or pieces of the reconstituted tobacco sheet fill out a cigarette or cigar firmly. This ability to firmly fill out a cigarette or cigar is referred to as the filling power of the tobacco. Conventional reconstituted tobacco has much better filling power than the stems or fine fragments of natural tobacco from which it is often made, but its filling power may be inferior to some types of natural leaf tobacco. To achieve any particular amount of cigarette or cigar firmness, it is obvious that tobacco having improved filling power will enable the manufacturer to use less tobacco. Hence, a tobacco product having increased filling power as compared to an otherwise identical product is certainly desirable.

It is therefore an object of the present invention to provide a method of making reconstituted tobacco sheet which, when cut up or shredded, has a filling power greater than pieces or shreds of an otherwise identical sheet.

As is known, one process for making reconstituted tobacco involves treating natural tobacco to separate soluble extractibles from the fibrous portion, conversion of the fibers by papermaking techniques into a paper-like fibrous web, and incorporation in the web of the extract to restore the soluble tobacco ingredients. The present invention involves an additional step to the procedure outlined above, namely, that of creping the reconstituted tobacco sheet.

In a broader sense, the invention involves creping a reconstituted tobacco sheet regardless of the process by which the sheet was produced.

The accompanying drawing illustrates, schematically, an apparatus for creping a reconstituted tobacco sheet, the apparatus itself being well known.

The first step in carrying out the present invention is the formation of a reconstituted tobacco sheet. One way of producing such a sheet is to extract the soluble ingredients of natural tobacco, which preferably has been macerated or comminuted in preparation for extraction. The extraction is performed by use of water, and generally withdraws from 25% to 60% by weight of the starting material. An aqueous slurry is then formed containing the fibers, and by usual papermaking techniques, the slurry is transformed into a self-sustaining web. The tobacco extract is then introduced into the Web. The application of the extracted tobacco material may be achieved in any appropriate manner, as by spraying, saturating, or otherwise.

Another way of producing a reconstituted tobacco 3,430,634 Patented Mar. 4, 1969 sheet involves pulverizing natural tobacco and forming an aqueous slurry including the pulverized tobacco and a binder. The slurry is extruded onto a moving belt, whereon it takes the form of a tobacco-carrying film.

Still another manner of making a reconstituted tobacco sheet is similar to the first method described above, except that no extraction is performed. Thus, natural tobacco is formed into an aqueous slurry, and the slurry is transformed into a web by papermaking techniques. In such a procedure, the liquid portion of the slurry is saved and reused so that the soluble portion of the tobacco is not lost.

According to the present invention, after the reconstituted tobacco web is formed it is creped. The creping can be accomplished by pressing the web, while moist, against a support roll 10. The web 11 is advanced, in the direction of the arrow in the drawing, onto the periphery of the roll 10, which rotates in the direction of the arrow. The moist web is pressed against the surface of the support roll 10 such as by a pressure roll 12. As the support roll 10 continues to rotate, the still moist sheet 11 is creped off the roll 10 by a creping doctor 13, as a result of which the sheet takes on a wavy shape, as indicated at 14. When the creped, reconstituted tobacco sheet thereafter dries to its normal moisture level, the Wavy shape becomes set in the sheet. If desired, a second doctor 15 may be provided to clean the roll 10.

A conveyer 16 may be provided for receiving the creped tobacco product as it leaves the support roll 10, and for carrying the tobacco product to a suitable apparatus in which it is dried. Thereafter, the reconstituted tobacco sheet may be cut to provide filler material for a smokable article, e.g., shredded to form cigarette filler material. Shreds of the dried, creped reconstituted tobacco sheet have been found to possess greater filling power than shreds of an uncreped reconstituted tobacco sheet.

If the first method described above is employed to make the web of reconstituted tobacco, the web is creped between the time it is impregnated with the extract material and the time it is dried to its normal moisture level. In such a case, the roll 10 may be a roll which supports the web 11 during the impregnation step, or it may be a separate roll provided solely for purposes of creping the web. In either case, the web will be moist with the tobacco extract at the time it is pressed against roll 10 and then creped off.

Tests on both bulk shredded tobacco and on finished cigarettes have been made to indicate the improved filling power of tobacco products according to this invention. The bulk tests were performed by the method described in the article, Measure of the Filling Optimum of Cigarettes-The R Meter, by Andre Pietrucci, Annales S.E.I.T.A.D.E.E., Section 1, 1965, No. 3. To practice this method, an instrument defining a chamber of fixed volume is used, the chamber having a flexible bottom wall operatively connected to a mercury monometer. Samples of bulk shredded tobacco are placed in the chamber and, after the tobacco is compressed to the fixed volume, the pressure which each sample exerts on the flexible bottom of the chamber is read on the monometer. By comparison with tobacco from manufactured cigarettes, it can be determined that a certain pressure reading corresponds to the firmness of a satisfactory cigarette. A series of pressure readings is made in each of which a different weight of tobacco is placed in the chamber. Then, from this information, the weight of tobacco producing a pressure corresponding to the previously determined standard is found.

The cigarette tests were performed by making cigarettes with different weights of creped tobacco and different weights of otherwise identical uncreped tobacco,

and subjecting the cigarettes to a compressibility tester to indicate their relative firmness. This tester includes a rounded, weighted plunger, the shape and weight of which is intended to simulate pinching of the cigarette with the fingers. The depth of depression of the plunger into each cigarette is measured in millimeters, and therefore, comparison of the readings is an indication of the relative firmness of any cigarette.

Specific examples of the tests are set forth below.

EXAMPLE I A reconstituted tobacco sheet was manufactured, by the first method described above. A length of the sheet was obtained without creping for use as a control. Another length of the sheet was creped, the creping serving to shorten the sheet to such a degree that the lineal speed of the sheet 14 leaving the roll 10 was 47% of the speed of the sheet 11 arriving at the roll 10. The relationship between the speeds of the sheet arriving at and leaving the creping roll is, of course, an indication of the amount of crepe introduced into the sheet. The creped and uncreped sheets were then shredded by identical cutting procedures, so that the width of the shreds was identical.

Various samples of the creped and uncreped shreds were placed in the test chamber referred to above, it having been determined that a reading of 6 pounds per square inch on the monometer corresponded to the firmness of a commercial cigarette. The weight of uncreped, control tobacco which gave this standard reading on the monometer corresponded to a specific volume of the sample of 3.05 cubic centimeters per gram (cc./gm.). In contrast, the weight of creped tobacco which gave this standard reading corresponded to a specific volume of the sample of 3.78 cc./ gm. Thus, it will be appreciated that the creped product had a filling power 24% greater than the uncreped product.

EXAMPLE II Cigarettes of all five sets were subjected to the compresa sibility tester of the type described above. The plunger weighed 394 grams. The results of the tests are tabulated below, the depth of compression reading being the average ten readings of each set:

Type Tobacco A set of commercial cigarettes was also subjected to the compressibility tester, and the average reading was found to be 0.7 mm.

From the tabulation above, it will be seen that the filling power of the creped tobacco falls somewhere be tween 15% and 35% greater than the comparable uncreped tobacco. This confirms the finding of a 24% in crease in filling power mentioned in Example I.

The invention has been shown and described in preferred form only, and by way of example, and many variations may be made in the invention which will still be comprised within its spirit. It is understood, therefore, that the invention is not limited to any specific form or embodiment except insofar as such limitations are included in the appended claims.

What is claimed is:

1. A process for making a tobacco product for use in a smokable article, comprising the steps of forming a reconstituted tobacco sheet, applying the sheet while moist to a creping roll, creping the moist sheet by doctoring the sheet from the roll, and cutting it into pieces suitable for use as filler material in a smokable article.

2. A process as defined in claim 1 wherein formation of the sheet comprises the steps of separating natural tobacco into fibrous material and extract material, forming the fibrous material by papermaking techniques into a paper-like sheet, and impregnating the sheet with said extract material, and wherein said sheet is applied to the creping roll while still moist from impregnation of the extract.

References Cited UNITED STATES PATENTS 1,647,694 11/1927 Hawkins 131-14 3,230,958 1/1966 Dearsley l3114 X 3,298,378 1/1967 Stevens et al 131140 FOREIGN PATENTS 1,146,420 3/1963 Germany.

MELVIN D. REIN, Primary Examiner.

U.S. Cl. X.R. 131--147, 14, 143

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