US1833804A - Manufacture of paper making material - Google Patents

Description

Patented Nev. 24, 1931 UNITED STATES PATENT oFFicE KO WATANAJBE, OI HIGASHI-KU, NAGOYA, JAPAN MANUFACTURE OF PAPER MAKING MATERIAL No Drawing. Application filed November 1, 1929, Serial No. 404,211, and in Japan February 23, 1929.

This invention relates to improvements in the manufacture of paper. making and has for its object to recoverpulp from old printed paper by de-inking. a

The characteristic feature of this invention is to make an emulsion of turpentine oil, a solvent of printing ink and dryprintingink, by the action of a suitable dispersing medium such as soap solution, and to mix the resultant emulsion of turpentine oil with old printed paper preliminarily treated with alkali and thereupon de-inking the same by dissolution and dispersion of ink matter on the old printed paper into the said dispersed solvent oil.

The object of this invention is to attaln the de-inking of old printed paper easily and completely and to recover useful paper making material of the same grade as that of. the old paper used, by a simple and economical process.

Heretofore old printed paper has not been utilized as a raw material for the recovery of high grade paper pulp on account of the difliculty of de-inking. But, by the. im-

proved method of this .invention such old printed paper may be satisfactorily used as raw material for the same purpose, and also a successful utilization can be attained of waste, old printed paper, which is of great demand. I 1

The execution of this invention is as follows: To make an emulsion of turpentine oil a solution of soap as dispersing medium is 5 made of any sort of fats or oils such as soap of sesame oil.

' To explain this more fully about 30 lbs. of such soap of sesame oil is dissolved in a proper quantity of water, this solution is then mixed with about 25 litres of turpentine oil, the resultant mixture is then agitated violently thus producing the emulsion of turpentine oil.

5 The next treatment 'is the tearing onbreaking up of old printed paper. For this purposea paper making kneading machine is used, andto about 1,000 lbs. of old paper about 3 p proper quantity of water are poured down into the kneading machine through respec is very small. But these spots may be comlbs. of caustic soda solution, and a.

tive supply pipes provided at'the charging portion of the kneading machine. In kneading of this paper mixture old paper is greatly softened by the. action of coexisting chemicalcaustic soda, so that the kneading action proceeds much easier than when kneaded with water only.

The kneaded paper mixture, which is black in colour, is discharged from the kneading machine, and thenpoured down into the paper making potcher or the mixing machine and now said emulsion of turpentine oil is added to this mixture, then the entire mass is agitated by constant circulation for about thirty minutes. potcher or the mixing machine dry printing ink on old printed paper is completely peptized intominute particles, and as aresult of this the pigment contained in printing ink such as lamp black is also completely sus- 70 pended in the dispersed solvent oil. This dispersed mixture, therefore, contains minute particles of peptized ink matter so that when one scoops up and presses this mixture in the hands a blackish muddy liquor willbe 7 separated from the mixture and a white paper fibre will be retained in the hands.

A greater part of this blackish muddyliquor, which has been completely peptized during the agitation'in the potcher or the 50 mixing machine, is then separated from the peptized paper mixture by using an apparatus such as centrifugal separator. The re maining fibre of paper thus gained is then poured into the potcher or the mixing ma- 35 chine'with water and thereafter repeatedly washed by the drum washer or poured down into a tank having a mat stretched over the bottom and provided with agitators and in this tank the muddy liquor is to be filtered v and separated. Inactual practice of this washing process, there rarel appears minute black spots on the washed pulp mixture even if the latter pletely removed by washing andby adding a small quantity of alkali, assaid phenomena of black spots is chiefly due to a lack of the alkalinity of he kneaded paper mixture. m Moreover this removing effect is better at- During this agitation in the I tained when a small quantity of soap is added with the alkali. The resultant product after washing is completely de-inked consisting of fibre from old printed paper;

The produced material thus gained is then made up to dry pulp by a pulp machine or into paper by being poured directly into a beater.

I claim:

Method of manufacturing paper making material consisting in preparing an emulsion of turpentine oil, with a good solvent of printing ink and dry printing ink, by the action I of soap solution, as a suitable dispersing medium, then mixing the resultant emulsion of turpentine oil with 'old printed paper preliminarily treated with alkali and thereupon de-inking the old printed paper by the dissolution and dispersion into the said dispersed solvent oil.

' In witness whereof I have hereunto set my my hand.

v KO WATANABE.