USRE10328E - Manufacture of paper-pulp - Google Patents

Description

UNITED STATES PATENT. ,OFFIcs.

GEORGE AROHBOLD, on oswseo, NEW YORK.

MANUFACTURE OF PAPER-PULP.

' ments particulsrlyuseful in the art of mannfacturiug paper-pulp, of which tho'followiu'g is a specification.

My invention relates to the treatment of wood, straw, rags, or any-other suitable substance of a cellulose or fibrous'natnre for converting the same into paper'pulp; andit has for its objectthe complete separation of the gummy and resinous matters and tannin from the fiber, and the production of a paper-pulp of superior-quality and-in increased quantity fromathe aforesaid substances, by "producing acid sulphite of lime in the structure, orilrthe flbjer itself oijthe substance treated, whereby more eflicient action of .-the salt is secured.

.The peculiar force 'known as catalytic action," as fully demonstrated by Liebig and others,operatesin such a way thatcertain gases. when united with basesuch as hydrate of lime, (or example-in the pr sence of moist por-' ous or fibrous substances, increase reducing action, so that it is not only more complete,

but the resulting salt produced is itself more powerful. I'a'vail' myself or this important principle in. the manufacture of paper-pulpL. Various methods have heretofore'been devised for. subjecting such substances to the action of sulphnrous acid or its salts; but these, in' a -'perfections attending such methods are that the reducing action is to a. large extentlost.

Therefore the resulting product is not so pure,

. and in quantity it is less than when produced by my method. Another disadvantage is that such ordinary methods cause corrosive action on the vessels used unless they are-lined with lead,and little more than one-halfof the proper reducingel'ectsis obtained by such methods. I avoid these objections by my improved process and materially reduce the time and espouse heretofore required to make paperfpulp ofsuperior quality, and the-following directions will enable those skilled in the art to avail themselves of my inventiom -I cut the wood or other suitable substance into convenient pieces, so thstchemicals may 'BPKOIFICATIOR forming part of Beissued-LetterYPatent" No. 10,818, dated May 22, 1883.

I Original No. 274,23, dated Man-.nm'mes. I

Application for reissue filed-April 25,1883.

come quickly into intimate contact with and eflicieut action upon thefiber. Thenfill an ordinary digester or other suitahle'apparatus about three-fourths full with the pieces. Then put in from any convenient part of the digester,

by means of a pipe or an opening-at the top,

for example,,dilute milli of lime, preferably at ordinary temperature, or 62 Fahrenheit, but this temperature may be varied considerably,) until the'wood or other substance is covered. The dilute milk of lime should con taln from one to six per cent. of hydrated lime, the rest being water. The p'er cent. of lime will necessarily vary as stated, because'ot the'varying nature of the fibrous substances to be treated. Thus,

woods, and a liquid containing oneper cent.

.0! liinef. wouldhmsuitahle. for its Hard woods, however, and those containing nch resinous matter, will require the extreme proportion of lime, because more powerful-action of the lime is required to speedily afi'ect their structure. I then pass in from any convenient part of the digester,.by gany usual means, sulphurous-acid gas. preferably but not necessarily com-pressed. Sometimes the mixture will. take more; and sometimes less sulphurousacid gas; but the proper quantity may be determined by the use of blue litmuspaper, as, when the mixture will turn blue litmus-paper distinctly .red enough gas has-been introduced In. some cases when hard, dense wood is used, I use in the diluted milk ol' lime about one pound of nitrate of lime for'every one hundred pounds of wood; hutin ordinary cases this is not necessary. When the mixture givesa'distinct acid reaction with blue litmuspaper, as aforesaid, there is produced between the fibers and inihe libe'r'acid sulphite of lime:

with a slight trace of sulphate. This reaction causes partial disintegration of the wood or other substance.com pletely red uces the gummy and resinous bodies between the fibers, and produces-a fibrous masssomewhat resembling what paper-makers term half-stall? Next'I subject the mass to steam-pressure, preferably I'sush out the chemicals used with'uater, which lsaves'tbe productpure cellulose refibrous heiubling cotton-wool. It bleaching should be necessary, as it may {be in case certain dsrk-coloredsubstunces areused, and it is desirable to make white-paper; a good processis as follows, viz: Use for every 'huudred'pounds of'dry pulp three node of chloride or limegand one ounce of sulphate roof alumina. D ssolve the acid sulphuts of i alumin'ein waiterpud add it to the mixture of chlorldeof lime endwater and mix yith the ,Jmlp. Thesechemicals maybe washed out .atterward with water. The product obtained 1 5 can be further'haudled by pulp or paper malt-- 'ers in the usual manner. v

Having thus described my iuvention,what I claim to be new and desire to secure by Letters Patent of the 'dnited States, is- Y 1 a 1. 'In the art ct manufacturing paper-pulp,

a amass the processor disintegrating celluioseor other vegetable material herein described, which. consists in producing the acid sulphite of lime in the structure of the substance treat- 'stsnti'ully as setfcrth.

. 2. The improvement in the art of manufacturing paper-pulp herein described, which consistsin first cutting the vegetable substance to be treated into suitable pieces, than treato iug it's-1th dilute milk of lime, then subjecting it; to the action of snlphurous-acid gasftheu subjecting'itto steam-pressure, and -.then -re-' hereinbefore set forth. v

GEORGE ARGHBOLD.

gwitnesses:

'. mucus S. Hgrxms,

Hm? L. Howrr.

moving the chemicals used, substantially as a ed by the chemical treatment employed, sub- :5