US1138085A - Method of removing ink from paper-stock. - Google Patents

Description

r'r mans near rare MAX CLINE AND CHARLES F. RHODES, OF GLENS FALLS, NEW YORK, ASSIGNORS TO INTERNATIONAL PAPER COMPANY, OF NEW YORK, N. Y., A

CORPORATION OF NEW Patented May 4, i915.

. YORK.

I METHOD OF REMOVING" INK FROM PAPER-STOCK.

1 ,138 Q 85. Specification of Letters Patent.

No Drawing.

To all whom it may concern: Be it known that we, MAX GLINE and CHARLES F. Rnonns, citizens of the United skilled in the art to which it appertains to make and use the same.

This invention relates to a certain new and useful improvement in the removal of printers ink from old paper stock, that is to say from stock made up in whole or in part ofwaste printed-paper, as, for instance, from old newspapers, printed books, and the ike; I

In the practice of the invention, the waste paper stock is macerated in the presence of water in a beater engine or any machine for reducing it to a substantially homogeneous pulp. To the original or macerated stock, containing the ink to be removed, is added a caustic alkali, in solution, preferably caustic soda, which has the effect of lifting the ink from the fiber. There is also added to the original or macerated stock a quantity of silicate of aluminum such as fullers earth, kaolin and all other clays or silicate of magnesium such as talc, soapstone, etc., which serve to take up, absorb, or carry the ink, thereby segregating it from the fiber. Finally, by a washing operation, the aluminum silicate or clays, carrying with it the ink, is separated from the fiber, thereby bringing the stock back quite closely to the original condition and color of raw stock.

As an illustration of the successful practice of the invention, it may be stated that successful results may be obtained by first macerating the waste printed paper stock or book stock with the necessary amount of water to bring it to a pulp. This operation can be carried on in a beater engine or in any other suitable type of pulping machine, and with water at ordinary atmospheric temperatures. To the macerated or pulped stock is then added the caustic alkali and the absorbing agent, in the proportion of,

Application filed November 27, 1911. Serial No. 662,579.

say, forty pounds of caustic soda (sodium hydrate), and forty pounds of aluminum silicate or clay, per ton of the pulped stock of beater consistency. The caustic alkali thereupon exercises its function of lifting the ink from the fiber ofthe stock and the aluminum silicate or clay is found to absorb, take up, and carry the ink, thereby segregat ng it fromthe fiber. The operation is facilitated and made uniform by vigorously agitating and mixing the mass for a period varying from say ten minutes to thirty mlnutes according to the character of the stock employed and the desired completeness of the result. In some instances, also, it may be further facilitated by raising the temperature of the stock by the injection of steam or the addition of hot water. Thereupon the aluminum silicate or clay, carrying the ink, is washed from the fiber in any suitable manner, as, for instance, in the drum washer in common use in paper mills, in which also the stock may be macerated, treated and washed, or by any other washing method desirable.

What we claim is:

1. The process of removing ink from waste newspaper stock, book stock, and the like, which consists in pulping the stock, adding a caustic alkali thereto for lifting the ink, adding aluminum silicate or clay, to absorb the lifted ink, and washing out the ink-carrying absorbent; substantially as described.

2. The process of removing ink from wastev newspaper stock, book stock, and the like, which consists in pulping the stock, lifting the ink by adding about 2% of caustic soda, absorbing the lifted ink by add;