US2580608A

US2580608A - Forming cigarette paper

Info

Publication number: US2580608A
Application number: US665001A
Authority: US
Inventors: Milton O Schur; Robert M Levy
Original assignee: Ecusta Paper Corp
Current assignee: Ecusta Paper Corp
Priority date: 1946-04-25
Filing date: 1946-04-25
Publication date: 1952-01-01
Anticipated expiration: 1969-01-01
Also published as: GB646030A

Description

Patented Jan. 1 1952 UNITED STATES PATENT OFFICE assignors to Ecusta Paper Corporation,

a. corporation of Delaware No Drawing. Application April 25, 1948, Serial No. 685,001

2 Claims. 1

Our invention relates to cigarette paper and more particularly to improving the burning properties of the paper when the cigarette is smoked so that the resulting ash has desirable properties.

An important feature of our invention is the modifying of the burning properties of cigarette paper to avoid formation of carbonized paper particles that commonly appear as black curling ashes. Such ashes tend to flake oif and fall from the cigarette onto the smokers clothes.

We have discovered that by certain chemical treatment, described hereafter, of the pulp or furnish from which the cigarette paper is made, the black, falling ashes can be substantially eliminated. Moreover, a clinging, grayish-white ash of pleasing appearance is produced when the cigarette using this paper is smoked. The ash produced is more cohesivethan usual, and while it may be flicked off easily at the will of the smoker, it is sufliciently cohesive and integrated to avoid the frequent accidental dropping of the ash on the smokers clothes.

It has been proposed heretofore to improve the burning and ash characteristics of cigarette paper by incorporating various types of chemical compounds, such as for example, water soluble borate, tungstate, sulfate and phosphate salts, in the cigarette paper during formation of the paper web on the paper machine. Such applications are usually carried out by immersion of the paper web in a bath of the chemicals, or by spraying a solution of the chemicals onto the preformed paper sheets.

These procedures have several practical disadvantages that hamper commercial production. For example, the drying capacity of the paper machine is substantially reduced by the rewetting of the paper sheet with the aqueous solution of the chemicals, and non-uniformity of application of the chemicals to the sheet, particularly where the chemicals are applied with a spray. These difficulties cannot be avoided by introducing the chemicals into the paper stock prior to web formation of the paper machine because of their water soluble character and consequent loss of these chemicals from the paper furnish before or during the formation of the paper sheet.

In accordance with our invention we avoid the practical limitations of the above prior procedures by utilizing certain chemicals that can be introduced into the paper furnish in the heater or in the machine stock chest and before the furnish reaches the paper machine. We have discovered that by incorporating caustic alkali in certain amounts in the furnish from which the paper is made that the desired improvement in the ashing qualities of the paper is obtained. The alkali that we have found commercially advantageous because of its efliciency, availability and low cost, is sodium hydroxide. It can be used as such or partially or completely neutralized with an acid, preferably phosphoric acid. The combination of caustic soda and phosphoric acid has given us particularly good results from the standpoint of ash appearance and behavior.

We have found it especially important to add the alkali to the bleached or to the finished pulp ready for web formation on the paper machine, so that a certain proportion of that added will be retained in the finished paper.

An advantageous procedure for carrying out the process of our invention is as follows:

To the beaten pulp in the machine stock-chest we add 2 /2% caustic soda (based on weight of pulp) in the. form of a 2% solution. About fifteen minutes after the caustic soda has been mixed into the stock, we add 1%% phosphoric acid (based on weight of pu p) in the form of a solution containing approximately 25% phosphoric acid. The final stock density in the chest is about 2 /2%. The filler, which is calcium carbonate, is now added in the desired proportions, for example, based on fiber, of which about 70% will be retained in the paper. This addition may take place in the chest or in the stock-line between I the Jordan and the paper machine headbox.

The proportions of caustic soda and phosphoric acid in relation to the weight of pulp may be varied. In general we prefer to maintain the caustic soda usage between and 5% based on weight of pulp; the phosphoric acid may vary from nothing up to an amount equal to that of the caustic soda, and preferably about to 5% phosphoric acid, based on weight of pulp fiber.

Caustic soda alone will improve the tendency of the paper ash to cling to the tobacco; the addition of phosphoric acid to the caustic soda tends to reduce the size of the flakes.

If higher quantities of caustic soda and phosphoric acid are used than correspond to our upper limits, the paper is apt to be fire-resistant, and to char when the cigarette is smoked. Indeed, the cigarette may go out.

Instead of adding the caustic soda to the pulp in the stock-chest as above described, all or part of -it may be added to the pulp while the latter is in the beater, and at any stage of the beating. We have found that addition of at least part of the caustic soda early in the beating operation tends to reduce the power consumed in beating.

An important practical advantage of our above described process is that the improved ashing characteristics of the paper, produced thereby, do not change with the age of the cigarette. This is contrary to some of the prior processes for improving cigarette paper which give initial improvement in ashing properties but which improvements are lost upon ageing of the cigarette.

The filler, for example calcium carbonate, mentioned above, is the principal ash producing constituent of the cigarette paper, and is recited in the claims herein as an ash producing filler.

Various modifications and changes may be made in the foregoing process, materials and products, without departing from the spirit and scope of our invention as defined in the ,appended claims.

We claim:

1. The process for producing cigarette paper which when burned as the wrapper on a cigarette will produce a clinging, grayish-white, ash that is sufliciently cohesive and integrated to avoid frequent accidental dropping of the ash, comprising incorporating in the cigarette paper furnish just prior to sheeting thereof on a cigarette paper making machine andwhich furnish contains predominantly cellulosic fibers and calcium carbonate flller, approximately /2% to 5% of sodium hydroxide and phosphoric acid in an amount of about /z% to about 5%, based upon the weight of the fiber and in an amount not greater than a the amount of sodium hydroxide, and then sheeting this furnish'on the paper machine and drying the resulting cigarette paper sheet in such a manner that the finished cigarette paper contains a substantial amount of the reaction products of said sodium hydroxide and phosphoric acid.

2. The process for producing cigarette paper which when burned as the wrapper on a cigarette will produce a clinging, grayish-white ash that is suiliciently cohesive and integrated to avoid frequent accidental droppingof the ash, comprising incorporating in the beaten and washed cel- 4 lulosic flber pulp from which the cigarette paper sheet is to be formed, approximately 2 sodium hydroxide, then incorporating in this furnish approximately 1 phosphoric acid in the form of a solution containing approximately 25% phosphoric acid, incorporating in the furnish approximately calcium carbonate filler, and then sheeting this furnish on the paper machine and drying the resulting cigarette paper sheet so that the finished cigarette paper contains a substan tial amount of the reaction products of said sodium hydroxide and phosphoric acid.

MILTON O. SCHUR.

ROBERT M. LEVY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Technical Association Papers, Series XXI, pgs. 367 to 372 (1938).

Technical Association Papers, Series m, pgs. 464 and 465 (1941).

Technical Association Papers, Series 25, page 327 (1942).

Journal of Physical Chemistry, volume 44, pgs. 535, 536, 539, 542, 570, 571 (1940).

Paper Trade Journal, April 11, 1929, page 54.

Claims

1. THE PROCESS FOR PRODUCING CIGARETTE PAPER WHICH WHEN BURNED AS THE WRAPPER ON A CIGARETTE WILL PRODUCE A CLINING, GRAYISH-WHITE, ASH THAT IS SUFFICIENTLY COHESIVE AND INTEGRATED TO AVOID FREQUENT ACCIDENTAL DROPPING OF THE ASH, COMPRISING INCORPORATING IN THE CIGARETTE PAPER FURNISH JUST PRIOR TO SHEETING THEREOF ON A CIGARETTE PAPER MAKING MACHINE AND WHICH FURNISH CONTAINS PREDOMINANTLY CELLULOSIC FIBERS AND CALCIUM CARBONATE FILLER, APPROXIMATELY 1/2 TO 5% OF SODIUM HYDROXIDE AND PHOSPHORIC ACID IN AN AMOUNT OF ABOUT 1/2 TO ABOUT 5%, BASED UPON THE WEIGHT OF THE FIBER AND IN AN AMOUNT NOT GREATER THAN THE AMOUNT OF SODIUM HYDROXIDE, AND THEN SHEETING THIS FURNISH ON THE PAPER MACHINE AND DRYING THE RESULTING CIGARETTE PAPER SHEET IN SUCH A MANNER THAT THE FINISHED CIGARETTE PAPER CONTAINS A SUBSTANTIAL AMOUNT OF THE REACTION PRODUCTS OF SAID SODIUM HYDROXIDE AND PHOSPHORIC ACID.