US1029848A - Process for the recovery of pulp from waste news print and other grades of paper. - Google Patents

Description

4 A FEED STATEd PATENT QFFKQEW,

. JOHN M. BURBY, OF ASTORIA, NEW YORK.

PROCESS FOR THE RECOVERY OF PULP FROM WASTE NEWS PRINT AND OTHER GRADES OF PAPER.

No Drawing.

Specification of Letters Patent. Patented June 18, 1912'. Application filed July 25, 1911. Serial No. 640,389.-

To all whom it may concern:

Be it known that I, vJon-1a M. BURBY, a citizen of the United States, and a resident of Astoria, Long Island, county of Queens, and State of New York, have invented a certain'new and useful Process for the Re covery of Pulp from Waste News Print and other Grades of Paper Made Partly of Ground Wood, the following being a full specification thereof.

A very large, if not the largest, partof all paper produced, is used for printing of daily newspapers and cheap periodicals, circulars, etc., and is thereby converted into waste almost before the ink of the printing has dried thereon. The verylarge demand for these grades of paper, and the growing scarcity of wood, press the necessity to recover the pulp from such waste papers-in a condition suitable for using it for the manufacture of the same grade of print papers. This could not be done heretofore, owing to the circumstance that the solvent agents, specified in the various processes heretofore known for the recovery of pulp from waste papers, produce a marked discoloration of the fibers of the mechanical wood pulp (ground wood) which is quite largely used as substitute for the chemical pulp in the manufacture of this so-called news print and of other cheap grades of print paper; these processes and the solvents specified therein, cannot be used for the recovery of pulp. from such waste news print papers and other grades of paper containing a proportion of such mechanical wood pulp; It should be stated, thatsome of the solvents, heretofore known, may be employed in sucha process under the conditions set forth in my pending application for Letters Patent filed June 15, 1911, Sr. No. 633,418. There are, however, some kinds or makes of such news print and of other, similar grades of paper, requiring to be boiled in the solvent s luti n or subjected to its action under a high temperature, to dissolve the sizing, or to cited a complete disassociating of the pulp fibers therefrom; such a treatment of the waste papers is also sometimes required to completely dissolve the adhesive ingredients of the printers ink, and to enable the carbon, or other pigment, to be separated from the pulp fibers and to be removed by washing.

The object of myinvention is to devise a process for the recovery of pulp fibers from waste papers containing a proportion of me- 4 chanical wood pulp (ground wood) in which process such waste papers may be boiled in the solvent solution or subjected to its action at a high temperature, without producing the discoloring and other detrimental efiects upon the fibers of this mechanical wood pulp; This object of my invention is attained 'y employing, for the treatment of such wa to papers, in the main ner hereinafter more fully described, a solution of borax, and the process is based upon my discovery, that boraxin solution does not produce a discolorationof the fibers of the mechanical wood pulp, and does not perceptibly affect their other physical properties, when such waste papers are subjected to its action at high temperatures, or are boiled therein, or even if the boran solution be stronger than required to dissolve or saponify the adhesive ingredients of printers ink and the cohesive ingredients of the sizing employed inthe manufacture of such papers. My experiments have demonstrated that if such waste news print papers are boiled in, or subjected under a correspondingly high temperature to the action of, a solution, containing approximately two pounds of borax in one thousand pounds of water, the oily and resinous ingredients of the printers ink, and the cohesive ingredients of the sizing, are liquefied and saponified sufiiciently to enable the fibers of the pulp to be separated therefrom, and that even a more concentrated solution of borax may be used in this way, without producing the discoloring, or any other detrimental effect upon the fibers of the mechanical wood pulp contained in the waste papers thus treated. The waste papers may he thus treated before being pulped or after having been pulped; the most practical method is, however, to use the borax solution in the beating engine. if the waste papers are to be treated with the horax solution after having been pulped in the beating engine, the quantity of water, contained in the pulped material, must be taken considerathrown in. A further supply of the bora-x solution and of the waste papers are successively added until the tank is filled to the full capacity of the beating engine. To secure the best results, about fifteen thousand (15,000) pounds of the solution should be used for every one thousand pounds of dry weight of the waste papers to be pulped in the beating engine and the initial strength of the solution should be somewhat in excess of'the stated standard (two pounds of dry weight of borax to one thousand pounds of water) because the borax, contained therein, is quite rapidly being consumed in saponifying the oily ingredients of the ink, which are first acted upon by the solution. The action upon the cohesive ingredients of the sizing takes place later, that is, when the Waste papers have become thoroughly permeated by the solution. The initial consumption of borax amounts to about eleven percent,- and is greater, if less than fifteen thousand pounds of the solution is used for each one thousand pounds of the dry weight of the waste paper stock.

By-the time when the Waste papers are thoroughly pulped, all cohesive ingredients of the printers ink and of the sizing are dissolved or liquefied, and the insoluble impurities, like the pigments of the ink, clay or other filler and the like, are commingled with the pulp fibers. The pulped material is then discharged from the beating engine into a chest, the liquid drained oil", as far as is practicable to be done without pressing, and the pulped material washed with fresh water. This washing can he done in the chest, if the chest is provided with some mechanical device for agitating the pulped material, and disposes of the borax solution, and of the dissolved or liquefied ingredients of the ink and of the sizing, remaining in the pulped material after draining. It is preferable to employ a mechanical agitator in the chest to save the handling of the ma terial. The washed material is then conveyed upon screens, or other suitable apparatus, where the insoluble impurities, like printers ink, clay, filler, etc., are separated from the pulp fibers and the latter collected.

Instead of pulping the waste papers in the borax solution, they may be subjected toits should be continued for about one hour or less. Then the liquor is drained off, as much as it can be, the pulped material washed with fresh water and conveyed upon screens, where it is treated in the same way as explained above, to separate the pulp fibers from the impurities. v

If the waste papers are to be treated with the borax solution before pulping them, they must be first dusted, and roughly separated,

before being charged into a boiler, or other suitable apparatus, filled with the borax solution. Approximately the same proportionate quantity of the borax solution should be employed. The boiler should be provided with means for heating the solution and it is desirable to provide also some means for agitating the papers while they are being acted upon by the heated solution. This treatment should be continued for not more than an hour and then the liquor is drained off, the waste paper discharged into a chest and after being washed in fresh water are conveyed into the beating engine. The pulped material is pumped upon screens and there treated with streams of water to separate the pulp fibers from the insoluble impurities, and the clean pulp collected. The pulp recovered by either way of conducting the process does not require any further treatment and may be conveyedto the paper making machine, or

stored for future use.

I claim as my invention: I

1. The process of recovering all pulp from waste print papers, madepartly of mechanical wood pulp, consisting of the following steps: (I) pulping and subjecting the waste papers to the action of an aqueous solution of borax; (2) draining and washing the material in fresh water; and (3) separating the pulp fibers from the impurities and collecting the clean pulp, substantially as herein set forth.

. 2; The process of recovering all pulp from waste print papers, made partly of mechanical wood pulp, consisting of the following steps: (1) pulping the waste papers in an aqueous solution of borax; (2) draining and washing the material in fresh water; and (3) separating the pulp fibers from' the impurities and collecting the clean pulp, substantially as herein set forth.

3. The process of recovering all pulp from separating the pulp fibers from the impuriwaste print papers, made partly of meties and collecting the clean pulp, substan chanical wood pulp, consisting of the foltially as herein set forth.

lowing steps; (1) subjecting the Waste JOHN M. BURBY. .5 papers to the action of an aqueous solu Witnesses:

tion of borax; (2) draining, washing and R. A. PIPER,

pulping the papers in fresh water; and (3) VERONICA BRAUN.