Improvements in the Treatment of Vegetable Materials for Obtaining therefrom Textile Fibres for Spinning Purposes and the like, and Cellulose for use in the Manufacture of Paper.
Year: 1890

page_text: Date of Application, 8th Nov., 1890-Accepted, 10th Jan., 1891
COMPLETE SPECIFICATION.
Improvements in the Treatment of Vegetable Materials for Obtaining
therefrom Textile Fibres for Spinning Purposes and the like, and
Cellulose for use in the Manufacture of Paper.
A communication from GEORG RUDEL, of Dresden, in the Empire of Germany.
I, ALFRED JULIUS BOULT M.I.M.E., of 323 High Holborn in the County of
Middlesex, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and hy
the following statement:―
This invention relates to a process of treating fibrous vegetable materials such as
straw, wood, esparto (or Spanish) grass, and the like so as to obtain on the one hand
and as a main product fibres fit for spinning purposes and on the other hand as a
secondary product cellulose adapted to be used in the paper manufacture.
This improved process differs from the well-known methods now used in the
treatment of the fibrous materials with compounds of sulphur with calcium, barium,
strontium, and magnesium, or with hydrates of alkalies, or the simultaneous use
of compounds of sulphur with the materials named and of compounds of sulphur
with alkalies.
The methods hitherto adopted for the production of cellulose from wood, straw or
the like have proved deficient in this, that although the incrusting substance is
dissolved the cellular tissue is destroyed to such an extent as to render the fibres
unsuitable for spinning. Now in the process forming the subject of this invention
the incrusting substance only is dissolved the bundles of fibres preserving their
natural length and firmness. Straw, for example, will yield fibres fit for spinning and
measuring each several inches in length, which when plaited, are far superior to the
original raw material.
The process consists in boiling the vegetable materials which may or may not have
been previously reduced or broken up into small pieces in boilers of wrought iron or
copper; in a mixture of water and of compounds of sulphur with calcium, barium,
strontium, or magnesium at a temperature of 100° C. or more at a pressure of not
over 10 atmospheres for a period of from one to ten hours. The amount of the sulphur
compound varies according to the nature of the vegetable material treated.
For the treatment of straw, for example, 1000 paris of raw material are treated
with 200 parts of sulphide of calcium and carbonate of sodium. The boiling is
continued for about four hours at a pressure of from 2 to 3 atmospheres in a boiler
entirely filled with lye,
The lye remaining after boiling is used again for a fresh charge of vegetable
materials sufficient quantity of the desired chemicals only being added thereto to make
up for what has been used up in the preceding operation.
In addition to the sulphur compounds mentioned, sulphides of sodium may be used
simultaneously with the sulphides indicated or if necessary, the corresponding
protosulphides may be used." Or the sulphides mentioned may be mixed with
hydrate of calcium, hydrate of sodium, hydrate of ammonium and carbonates of
alkalies. These mixtures are made during the boiling process the desired solutions being
introduced into the boilers by means of pumps and the like. As soon as the lye used
for boiling attains a density of from 10 to 20° Baume it is evaporated and then treated
so as to yield the alkalies it contains and also deliver the vegetable substances
dissolved in it.
The vegetable fibres obtained through the boiling process are then washed and the
fibres suitable for spinning separated from the short ones which are further treated to
produce pulp for paper manufacture.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is :-
The treatment of vegetable materials for the purpose of obtaining as a main product
fibres suitable for spinning and like purposes and as a bye-product cellulose for paper
manufacture by the employment of compounds of sulphur with barium or calcium or
strontium or magnesium either alone or mixed with carbonates or hydrates of
alkalies; or of compounds of sulphur with the above substances simultaneously
with sulphides of alkalies the vegetable materials being boiled with such mixtures in
closed vessels at a high temperature and pressure substantially as specified.
T
01
1800
W. P. THOMPSON & BOULT,
Agents for the Applicant.