Improvements in the Manufacture of Nitrocellulose, and Compounds thereof.
Year: 1895

page_text: Date of Application, 6th Mar., 1895
Complete Specification Left, 4th Dec., 1895-Accepted, 4th Jan.. 1896
Improvements in the Manufacture of Nitrocellulose, and Compounds
thereof.
We, ALFRED LUCK, of "St. Cuthberts," Hartford Road, Bexley, in the County
of Kent, Chemist, and ARTHUR HAMILTON DURNFORD, of The "Cottago
Dartford, in the County of Kent, Gunpowder Maker, both of the Firm of Pigon,
Wilks and Laurence, Limited, of Dartford aforesaid, Gunpowder Manufacturers,
do hereby declare the nature of this invention to be as follows:-
Our invention relates to the manufacture of nitrocellulose and compounds thereof
such as smokeless gunpowders and other explosives, celluloid and collodion.
Hitherto it has been found necessary to gelatinize or partly gelatinizo gun cotton
and other forms of nitrocellulose in order to adapt them as explosives suitable for
use in guns. This involves considerable cost for solvents such as acetone and the
like required to produce the desired gelatinous condition also the operations and
machinery necessary to produce a desired grain or shape are such that the plant
employed in the manufacture of black gunpowder is not available for these
operations.
According to our invention we produce nitrocellulose in a dense powdery form
which has peculiar physical properties, quite different from those of the ordinary
guncotton and other forms of nitrocellulose.
We effect this by destroying the structure of the cotton or other form of cellulose
from which the nitrocellulose is to be made by converting it into a dense powder
which we afterwards nitrate and wash free from acide.
To obtain the cellulose in the form of a donse powder we proceed as follows:
First, wo treat the cellulose material with known solvents whereby wo effect its
solution or partial solution.
Of the various solvents for cellulose we find the following most convenient :-
Sulphuric acid and water;
Zine chloride in aqueous solution ;
Zinc chloride in hydrochloric acid and water; and a mixture of caustic alkali,
carbon bi-sulphide and water.
We next separate the cellulose from its solution in a hydrated state in the form
of gelatinous granules. Where sulphuric acid or zinc chloride solution is used as a
solvent, we can obtain the hydrated state by simple dilution with water, and when
caustic alkali and carbon bi-sulphide solution is used, the hydrated state may be
obtained by heating the solution to the boiling point. In every case the solution
has to be kept in a constant state of agitation during the process of separating the
hydrated cellulose, and by this means we obtain it in the form of small gelatinous
granules. We prefer that the solution should be largely dilated with water, ns by
so doing, we obtain the gelatinous granules in a much finer state.
We then strain these granules from the liquid and thoroughly wash and purify
them either with water, or weak acids. We then proceed to dry the washed granules
so as to obtain the cellulose in a dense powder, and in order to do this wo
keep the material during the process of drying in a continual state of
agitation.
When the drying process is completed, the cellulose is in a dense powdery form
and when silted is ready for nitration.. In nitrating this material we use mixtures

page_text: of nitric and sulphuric acid, and we find the most convenient method is to allow the
powdered material to run through a feed or hopper into a vessel containing the mixed
acids while they are thoroughly agitated.
After the required degree of nitration is obtained we run off the acids and nitrated
material into a vessel from which after settlement the acids are drawn off leaving
the nitrated cellulose which can be further freed from acid by centrifugal machines
and then transferred to a washing tank and copiously washed until entirely free
from acid.
We find the following method convenient for effecting this :—
After transferring the material to a wasbing tank, it is copiously washed with
water which may be made to boil and kept in a state of agitation by the injection
of steam at or near the bottom of the vessel. The material is allowed to settle, the
acidulated water is drawn off, and the operation is repented until the water ahews
traces only of acid.
A further boiling carried on for some time with a neutralising substance, such as
carbonate of soda will remove the last traces of noid.
The material is then allowed to settle and the water is separated.
The nitrated cellulose thus obtained, can be used for any of the purposes for which
ordinary cellulose nitrates are now used, and by reason of its peculiar form, that of
a dense powder, we can also without having to apply solvents for gelatinizing
produce an explosive from it suitable for use in guns, by operations similar to those
by which black powder is manufactured. For example, we may further reduce it
to an inpalpable powder either by itself or incorporated with nitrates or other
ingredients. The product is then pressed into cakes and granulated or cut up into
pieces and finished like ordinary black gunpowder.
Or it can be pressed into moulds so as to obtain it in blocks of any desired
sliapc.
Dated this 8th day of March 1895
ABEL & IMRAY,
Agents for the Applicants.
Improvements in the Manufacture of Nitrocellulose, and Compounds
thereof.
66
We, ALFRED LUCK, of "St. Cuthberts," Hartford Road, Bexley, in the
County of Kent, Chemist, and ARTHUR HAMILTON DURNFORD, of The
Cottage," Dartford, in the County of Kent, Gunpowder Maker, both of
the Firm of Pigou, Wilks and Laurence, Limited, of Dartford aforesaid,
Gunpowder Manufacturers, 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 by the following statement :-
Our invention relates to the manufacture of nitrocellulose and compounds thereof
such as smokeless gunpowders and other explosives, celluloid and collodion.
Hitherto it has becu found necessary to gelatinize or partly gelatinize gun cotton
and other forms of nitrocellulose in order to adapt them as explosives suitable for
use in gune. This involves considerable cost for solvents such as acetone and the
like required to produce the desired gelatinous condition also the operations and
machinery necessary to produce a desired grain or shape are such that the plant
employed in the manufacture of black gunpowder is not available for, these
operations.
According to our invention we produce nitrocellulose in a dense powdery form
which has peculiar physical properties, quite different from those of the ordinary
gun cotton and other forms of nitrocellulose..

page_text: cellulose from which the nitrocellulose is to be made by converting it into a dense
powder which we afterwards nitrate and wash free from acids.
To obtain the cellulose in the form of a dense powder we proceed as follows :—
First, we treat the cellulose material with known solvents whereby we effect its
solution or partial solution.
Of the various solvents for cellulose we find the following most convenient :—
Sulphuric acid and water,
Zinc chloride in aqueous solution,
Zinc chloride in hydrochloric acid and water,
A mixture of caustic alkali, carbon bisulphide and water.
We next separate the cellulose from its solution in a hydrated state in the form
of gelatinous granules. Where sulphuric acid or zinc chloride solution is used as
a solvent, we can obtain the hydrated state by simple dilution with water, and
when caustic alkali with carbon bisulphide solution is used, the hydrated state
may be obtained by heating the solution to the boiling point. In every caso
the solution has to be kept in a constant state of agitation during the process
of separating the bydrated cellulose, and by this means we obtain it in the
form of small gelatinous granules. We prefer that the solution should be largely
diluted with water, as by so doing, we obtain the gelatinous granules in a much
finer state.
We then strain these granules from the liquid aud thoroughly wash and purify
them either with water, or weak acids. We then proceed to dry the washed
granules so as to obtain the cellulose in a dense powder, and, in order to do
this, we keep the material during the process of drying in a continual state of
agitation.
When the drying process is completed, the cellulose is in a dense powdery
form and when sifted is ready for nitration. In nitrating this material we use
mixtures of nitric and sulphuric acid, and we find the most convenient method is to
allow the powdered material to run through a feed or hopper into a vessel containing
the mixed acids while they are thoroughly agitated.
After the required degree of nitration is obtained we run off the acids and
nitrated material into a vessel from which after settlement the acids are drawn off,
leaving the nitrated cellulose which can be further freed from acid by centrifugal
machines and then transferred to a washing tank and copiously washed until
entirely free from acid.
We find the following method convenient for effecting this :-
After transferring the material to a washing tank, it is copiously washed with
water which may be made to boil and kept in a state of agitation by the injection
of steam at or near the bottom of the vessel.
The material is allowed to settle, the acidulated water is drawn off, and the
operation is repeated until the water shews traces only of acid.
A further boiling carried on for some time with a neutralising substance such as
carbonate of soda or of lime will remove the last traces of acid.
The material is then allowed to settle and the water is separated.
The nitrated cellulose thus obtained, can be used for any of the purposes for
which ordinary cellulose nitrates are now used, and by reason of its peculiar form,
that of a dense powder, we can also without having to apply solvents for gelatinizing
produce an explosive from it suitable for use in guns, by operations similar to those
by which black powder is manufactured. For example it may be rendered coherent
by addition of a little agglutinating material such as starch solution and rolled
into sheets or it may be reduced to an impalpable powder either by itself or
incorporated with nitrates or other ingredients and pressed into cakes; and the
sheets or cakes may be granulated or cut up into pieces and finished like ordinary
black gunpowder.
Or it can be pressed into moulds so as to obtain it in blooks of any desired
shape.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The hereindescribed manufacture of nitrocellulose in form of dense powder by
dissolving cellulose, treating the solution so as to obtain hydrated cellulose in granules,
drying, nitrating and washing the granules.
2. Nitro cellulose powder manufactured as above set forth.
ABEL & IMRAY,
Agents for Applicants.