Improvements in the Manufacture of Smokeless Explosives.
Year: 1895

page_text: Date of Application, 30th Aug., 1895
Complete Specification Left, 30th June, 1896-Accepted, 30th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Smokeless Explosives.
1, HUDSON MAXIM, of 55 Charing Cross Mansions, London, W.C., Chemist
and Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
The present invention relates particularly to an improved process or method of
manufacturing smokeless explosives and has mainly for its object to secure economy
in the use of solvents, to facilitate the manufacture, to save labour, and to obtain a
better product.
Heretofore in the manufacture of smokeless explosives for large guns it has been
usual to employ a very large percentage of nitro-glycerine, whether it be used with
high grade or low grade guncotton, or with both. When a large percentage of
gun-cotton has been used, (especially tri-nitro-cellulose or high grade guncotton)
it has been found that unless a large quantity also of nitro-glycerine be employed,
the explosive when made in large grains or rods is liable to warp or crack to pieces
in drying. This has been due to two reasons :-)
-First, to the large quantity of
solvents used, and therefore the large amount of shrinkage due to the use of so large
a quantity of solvent; and secondly, to the fact of a peculiarity that tri-nitro-cellulose
possesses of warping and cracking in drying.
I have discovered that if there be added to tri-nitro-cellulose from 5 to
10 per cent. of its weight of gelatin-pyroxylin, that is to say pyroxylin that is
soluble in nitro-glycerin, only a very small quantity of nitro-glycerin and a very
small quantity of solvent is needed, providing the materials are manipulated under
the influence of heat at a temperature at which they are readily soluble in
nitro-glycerin.
It is well known in the manufacture of ordinary commercial celluloid that if the
same be manipulated at a temperature of, or above, the melting point of camphor,
the camphor has a peculiarity of rendering the compound very plastic and yielding,
and adapting it to be moulded or formed into any desired shape. I have found
that, to a very great extent a compound of nitro-glycerin and gelatin-pyroxylin
produces a similar result or effect in the manufacture of smokeless explosives from
a compound consisting largely or mainly of tri-nitro-cellulose or high grade gun
cotton. The gelatin-pyroxylin and nitro-glycerin compound, furthermore, has the
additional desired effect of preventing the warping and cracking of the product in
drying.
In carrying out my invention I employ preferably about 80 per cent. of tri-nitro-
cellulose or pyrexylin of the highest degree of nitration, and to this I add about
8 to 10 per cent. of gelatin-pyroxylin; that is, pyroxylin soluble in nitro-glyceria
at a temperature of 100° to 160° F., or 60° C. It will thus be seen that I employ
two kinds of pyroxylin. A quantity of solvent, preferably acetone, is then mixed
with a quantity of nitro-glycerin equal to about 9 per cent. of the weight of the
two kinds of pyroxylin above mentioned. The amount of acetone employed is
preferably from 25 to 30 per cent. of the total weight of the final product, that
is to say the smokeless explosive. The materials are then placed into a suitable
mixer or agitator which is capable of being closed or sealed very tightly, and also
arranged to be heated externally by hot water or steam or other suitable heating
medium. Under the elevated temperature thus produced, and in the confined
space under pressure, the acetone or other solvent, is converted into vapour and
гр.

page_text: permeates every portion of the materials, and is very active as a solvent in
rendering the mixture plastic. After remaining in the agitator for a suitable
time, say 10 to 24 hours the materials are removed and passed continuously between
masticating rolls, such as those usually employed in the manufacture of common
celluloid. The rolls are preferably heated in order to facilitate the evaporation of
the solvent from the mixture and to facilitate the formation of the mixture into a
homogeneous plastic compound. The mixture is rolled continuously until a
sufficient quantity, or a sufficient percentage of the solvent has been evaporated
therefrom. There should remain in the material from 15 to 20 per cent. of the
original solvent first introduced., The existence of this percentage is determined
by weighing the quantity of materials that are taken from the mixer and
placed upon the rolls, and then by occasionally weighing the sheet of compound
formed it can be readily determined when a suitable quantity of the solvent has
been evaporated, by ascertaining the loss in weight suffered by the sheet of
compound.
The material is then rolled or formed into suitable sheets which are compactly
wound or rolled together and placed in a suitable stuffing cylinder, or cylinder
of a stuffing press, which is arranged to be heated externally. A suitable air pump
connected with the said cylinder is then set in motion and the air exhausted from
the interstices or spaces that are not occupied by the compound within the cylinder.
After the exhaustion of the air and after the said cylinder has been sufficiently
heated the materials within the cylinder are then compressed into one solid mass;
the heating of the cylinder is continued until all the materials contained within the
same are as nearly as practicable of uniform temperature, and at a temperature at
or above the point at which the gelatin-pyroxylin, or soluble pyroxylin, in the
compound becomes readily soluble in the contained nitro-glycerin; at this
temperature the said pyroxylin which is in combination with the nitro-glycerin
renders the whole compound plastic and yielding and performs practically the same
function as does camphor in the rendering of celluloid plastic by heating.
After the heating has been completed the materials are then "stuffed" from the
cylinder through suitable forming dies into any desired shape. After the material
has been thus "stuffed" from the cylinder into suitable lengths, and after the sticks
or rods thus formed have cooled, and while still in a more or less yielding condition
and before the remaining solvent has been evaporated therefrom, the sticks or rods
are cut into the desired lengths.
Dated this 30th day of August 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in the Manufacture of Smokeless Explosives.
I, HUDSON MAXIM, of 55 Charing Cross Mansions, in the County of Middlesex,
Chemist and Mechanical Engineer, 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:-
The present invention relates particularly to an improved process or method of
manufacturing smokeless explosives and has mainly for its object to secure economy
in the use of solvents, to facilitate the manufacture, to save labour, and to obtain
a better product than heretofore.
In the manufacture of smokeless explosives for large guns it has been usual to
employ a very large percentage of nitro-glycerin, whether it be used with high
grade or low grade gun-cotton, or with both. When a large percentage of gun-
cotton has been used, (especially tri-nitro-cellulose or high grade guncotton), it

page_text: has been found that unless a large quantity also of nitro-glycerin be employed, the
explosive when made in large grains or rods is liable to warp, or crack and
fall to pieces in drying. This has been due to two reasons :-First, to the large
quantity of solvent used and the consequent large amount of shrinkage; and
secondly, to the peculiarity that tri-nitro-cellulose possesses of warping and cracking
in drying.
I have discovered that if there be added to tri-nitro-cellulose from 5 to
10 per cent. of its weight of gelatin-pyroxylin (that is to say pyroxylin that is
soluble in nitro-glycerin) only a very small quantity of nitro-glycerin and a very
small quantity of solvent are needed, providing the materials are manipulated at a
temperature at which they are readily soluble in nitro-glycerin.
It is well known in the manufacture of ordinary commercial celluloid that if
the same be manipulated at a temperature of, or above, the melting point of
camphor; the camphor has a peculiarity of rendering the compound very elastic
and yielding, and of adapting it to be moulded or formed into any desired shape.
I have found that, to a very great extent a compound of nitro-glycerin and gelatin-
pyroxylin produces a similar result or effect in the manufacture of smokeless
explosives from a compound consisting largely or mainly of tri-nitro-cellulose or
high grade gun-cotton. The gelatin-pyroxylin and nitro-glycerin compound,
furthermore, has the additional desired effect of preventing the warping and cracking
of the product in drying.
In carrying out my invention I employ preferably about 80 per cent. of tri-
nitro-cellulose or pyroxylin of the highest degree of nitration and to this I add
about 8 to 10 per cent. of gelatin-pyroxylin; that is, pyroxylin soluble in nitro-
glycerin at a temperature of 100° to 160° F., or 60° C. It will thus be seen that
employ two kinds of pyroxylin. A quantity of solvent, preferably acetone, is then
mixed with a quantity of nitro-glycerin equal to about 9 per cent. of the weight of the
two kinds of pyroxylin above mentioned. The amount of acetone employed is
preferably from 25 to 30 per cent. of the total weight of the final product that
is to say of the smokeless explosive. The materials are then placed into a suitable
mixer or agitator which is capable of being closed or sealed very tightly, and also
arranged to be heated externally by hot water or steam or other suitable heating
medium. Under the elevated temperature thus produced, and in the confined space
under pressure, the acetone or other solvent, is converted into vapour and
permeates every portion of the materials, and is very active as a solvent in
rendering the mixture plastic. After remaining in the agitator for a suitable
time, say 10 to 24 hours the materials are removed and passed continuously
between masticating rolls, such as those usually employed in the manufacture of
common celluloid. The rolls are preferably heated in order to facilitate the
evaporation of the solvent from the mixture and the formation of the mixture
into a homogeneous plastic compound. The mixture is rolled continuously until
a sufficient quantity or a sufficient percentage of the solvent has been evaporated
therefrom. There should remain in the material from 15 to 20 per cent. of
the original solvent first introduced. The existence of this percentage is
determined by weighing the quantity of materials that are taken from the mixer
and placed upon the rolls, and then by occasionally weighing the sheet of
compound formed it can be readily determined when a suitable quantity of the
solvent has been evaporated, by ascertaining the loss in weight suffered by the
sheet of compound.
The material is then rolled or formed into suitable sheets which are compactly
wound or rolled together and placed in a suitable stuffing cylinder or cylinder of
a stuffing press which is arranged to be heated externally. A suitable air pump
connected with the said cylinder is then set in motion and the air exhausted from
the interstices or spaces that are not occupied by the compound within the
cylinder. After the exhaustion of the air and after the said cylinder has been
sufficiently heated the materials within the cylinder are then compressed into one
solid mass; the heating of the cylinder is continued until all the materials

page_text: contained within the same are as nearly as practicable of uniform temperature,
and at a temperature at or above the point at which the gelatin-pyroxylin or
soluble pyroxylin in the compound becomes readily soluble in the contained nitro-
glycerin at this temperature the said pyroxylin which is in combination with
the nitro-glycerin renders the whole compound plastic and yielding and performs
practically the same function as does camphor in the rendering of celluloid
plastic by heating.
After the heating has been completed the materials are then "stuffed" from the
cylinder through suitable forming dies into any desired shape. After the material
has been thus "stuffed" from the cylinder into suitable lengths, and after the sticks
or rods thus formed have cooled, and while still in a more or less yielding condition
and before the remaining solvent has been evaporated therefrom, the sticks or rods
are cut into the desired lengths.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described process of manufacturing smokeless explosives, which
consists in incorporating together tri-nitro-cellulose, nitro-glycerin and a nitro-
cellulose soluble in nitro-glycerin, and then moulding the mixture whilst at an
elevated temperature, for the purpose specified.
2. The herein described process of manufacturing smokeless explosives, which
consists in incorporating pyroxylins of different solubility with nitro-glycerin and
other and volatile solvents of one or more of the pyroxylins, then working or
kneading these substances whilst at an elevated temperature and in a confined space,
then moulding the plastic substance thus produced into the desired shape for use in
guns, and finally evaporating the volatile solvents from the moulded substance, for
the purpose specified.
3. The herein described process of manufacturing a smokeless explosive compound,
which consists in incorporating tri-nitro-cellulose, nitro-glycerin and a pyroxylin
soluble in nitro-glycerin at elevated temperatures, tegether with other and volatile
solvents of one or more of the pyroxylins, then rolling, masticating, or kneading
the compound at an elevated temperature, and evaporating therefrom a desired
limited proportion of the volatile solvents, then moulding the compound, whilst
still at an elevated temperature, into the desired shape for use in guns and finally
evaporating from said compound the remaining volatile solvents, for the purpose
specified.
4. In the manufacture of the herein described smokeless explosive compound,
placing the said compound in a receiver, exhausting the air therefrom, and then
pressing or moulding the compound into shape or partially into shape for use in
guns while the said compound is at an elevated temperature for the purpose
specified.
5. An explosive compound produced substantially as described and consisting of
tri-nitro-cellulose, nitro-glycerin, and gelatine-pyroxylin or a pyroxylin soluble in
nitro-glycerin at an elevated temperature.
Dated this 30th day of June 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.