Improvements in or relating to the Manufacture of Smokeless Powder.
Year: 1894

page_text: Date of Application, 17th Jan., 1894
Complete Specification Left, 5th Oct., 1894-Accepted, 10th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Manufacture of Smokeless
Powder.
I, MAX VON FÖRSTER, Engineer, Berlin, 20 Kleiststrasse do hereby declare the
nature of this invention to be as follows:-
The present invention relates to a process for the production of a very bulky,
smokeless powder, composed of various nitrated substances, such as gun-cotton,
otherwise nitrocellulose, nitroglycerine, giant powder etc., and to which non-nitrated
or only partially mitrated cellulose can be added.
The nitro-powders hitherto known, owing to their being gelatinized to the
utmost possible degree and the nature of the subsequent processes of manufacture,
possess a firm homogeneous structure, and have so far as cakes or cubes are
considered, a straight smooth surface. If the cakes or cubes are filled into
cartridge-cases, they lie very closely and thickly together, upon and next one
another, and there remains only a small amount of interstitial space between the
particles. Consequently the powder occupies a proportionately small space,
whereby when in use, manifold disadvantages and dangers are involved.
The sporting guns and rifles, now in use, are constructed for the old black-
powder, and not at all adapted for use with smokeless powders of the violent,
explosive or shattering kind. But as these guns are nevertheless costly there is no
ground for anticipating that they will shortly fall into desnetude; there is always
danger, consequently that sporting fire-arms owing to the increasing and widely
spreading use of such violent smokeless gunpowders, should burst in the act of
firing, involving danger to life and limb. But such danger arising and existing of
itself is greatly enhanced by the fact that the cartridge-cases are also constructed
for black-powder, have a large internal space in order that they may contain
enough black gunpowder, and in consequence of the construction of the fire-arms,
must also be retained.
If now such cartridge-cases should come to be used with nitro-powder the danger
arises that the cartridges owing to want of foresight or of knowledge, should be
overloaded. Such overloading must always take place, if the large space of the
cartridge case, adapted and intended for black gunpowder, be entirely filled with
the above named nitro-powder and the danger is so much the greater, the less bulky
the nitro-powder.
The object of the present invention is, therefore, to obviate this drawhack and
guard against the danger thus arising to life and limb especially to-the user of the
weapon; and this object is attained by the nitro-powder being produced in a form
more bulky than before; so that if even the whole of the available powder-space
in the cartridge case were filled with this improved bulky smokeless nitro-powder
there would neither be too great a weight of powder nor too great violence of
explosion in the act of firing the same inasmuch as the nitro-powders have a so
much greater power, exercise so much the greater and more injurious and dangerous
a pressure on the fire-arm the less space a given weight occupies and vice versa.
Thus cotton-powder first became such a powerful and shattering explosive, when
it was transformed from the flocculent condition of gun-cotton into the state of the
utmost possible compression in which it is now produced.
The greater volume thus materially diminishes the shattering power of the
nitro-gunpowders, and has furthermore a favourable effect upon the regularity of
their explosive action.
The required volume or bulk can be given to the nitro-powder in various ways.

page_text: If the powder is a cake or flake-powder it suffices to give the individual flakes a
curved hollow or corrugated form. This is effected by making the flakes
proportionately large and thin, so that in the drying process, which must be carried
out with the utmost possible rapidity they easily-warp and become crumpled.
Experience has shown that the most advantageous size in this respect is a square
of 3 millimetres by 1 millimetre in thickness. The object in view, a great increase
of bulk, may be even more effectually attained by only partially instead of
completely gelatinising nitrocellulose; the result obtained being that the cakes or
cubes of nitro-powder assume a loose and non-homogeneous structure and maintain
a roughened surface.
To this end, it is necessary to proceed as follows; highly nitrated cellulose is
mixed with feebly nitrated cellulose, in presence of a solvent e.g. alcohol and
sulphuric ether which entirely dissolves the feebly nitrated cellulose (collodion-
cotton) only and the highly nitrated cellulose (cotton-powder) only so far as the
feebly nitrated cellulose is present therein. The highly nitrated cellulose is
therefore left for the most part in its original form, and unaffected by the further
stages of the manufacture such as working the mass in a kneading machine or in
case cakes or cubes are to be produced, rolling and pressing into cakes or flakes
and cutting the latter and in case of the granular form being required, the grinding
of the mass into grains-gives to the gunpowder, whether in grains or cakes, the
desired, non-homogeneous loose and open structure and a rough surface.
The incomplete gelatinisation can further be promoted by employing in addition
to the highly and the feebly nitrated cellulose, pure non-nitrated cellulose, in a
comminuted, pulverulent condition thoroughly mixed with the highly nitrated
cellulose, as eg. in a rag-engine; or from the outset, the cellulose may be so
incompletely nitrated that a considerable proportion of non-nitrated cellulose
remains and the nitro-powder is made therefrom.
This incomplete nitration can for instance be also brought about by immersing
the cellulose for only a very short time in the nitric acid.
The non-nitrated cellulose undergoes no change whatever during the subsequent
gelatinization-process, and gives to the nitro-powder, by reason of its louse nature,
an extremely loose and open structure and a very much roughened surface.
The percentage of the non-nitrated cellulose to be employed depends upon the
quality of the nitro-powder desired in point of looseness of structure.
In the powders just described nitro glycerine may also be added, when the
materials are mixed together and undergo gelatinization together with them.
Dated this 17th day of January 1894.
COMPLETE SPECIFICATION.
Improvements in or relating to the Manufacture of Smokeless
.
Powder.
I, Max Vox FÖRSTER, Engineer of 20 Kleiststrasse, Berlin, in the Empire of
Germany, 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 to a process for the production of a very bulky,
smokeless powder.
The nitro-powders hitherto known, owing to their being gelatinized to the utmost
possible degree and to the nature of the subsequent processes of manufacture,
possess a firm homogeneous structure, and have a straight smooth surface. If the
Hakes are filled into cartridge-cases, they lie very closely and thickly together,

page_text: upon and next one another, and there remains only a small amount of interstitial
space between the particles. Consequently the powder occupies a proportionately
small space, whereby, when in use, manifold disadvantages and dangers are
involved.
The sporting guns and rifles, now in use, are constructed for the old black-powder
and are not at all adapted for use with smokeless powders of the violent explosive
or shattering kind. But as these guns are nevertheless costly there is no ground
for anticipating that they will shortly fall into disuse; there is always the danger,
consequently, that sporting fire-arms owing to the increasing and widely spreading
use of such violent smokeless gunpowders, may burst in the act of firing, involving
danger to life and limb. But such danger arising and existing of itself is greatly
enhanced by the fact, that the cartridge-cases are also constructed for black-
powder and have a large internal space in order that they may contain enough
black gunpowder, and in consequence of the construction of the fire-arms, must.
also be retained.
If therefore such cartridge-cases come to be used with nitro-powder the danger
arises, that the cartridges owing to want of foresight or of knowledge may be
overloaded. Such overloading must always take place, if the large space of the
cartridge case, adapted and intended for black gunpowder be entirely filled with
the above named nitro-powder and the danger is so much the greater, the less.
bulky the nitro-powder.
The object of the present invention is therefore, to obviate this drawback and
guard against the danger thus arising to life and limb especially to the user of the
weapon; and this object is attained by the nitro-powder being produced in a form
more bulky than before, so that if even the whole of the available powder-space in
the cartridge case were filled with this improved bulky smokeless nitro-powder
there would neither be too great a weight of powder nor too violent an explosion
in the act of firing the same, inasmuch as the nitro-powders have so much greater
power, and exercise so much the greater, more injurious and dangerous a pressure
on the fire-arm the less space a given weight occupies.
Thus cotton-powder first became such a powerful and shattering explosive, when
it was transformed from the flocculent condition of gun-cotton into the state of the
utmost possible compression.
The greater volume thus materially diminishes the shattering power of the nitro-
gunpowders, and has furthermore a favourable effect upon the regularity of their
explosive action.
To give the required volume or bulk to the nitro-powder any known method
may be applied, according to which the nitro-cellulose is incompletely gelatinised,
that is to say, highly nitrated cellulose is mixed with feebly nitrated cellulose, in
presence of a solvent e.g., alcohol and sulphuric ether, which entirely dissolves the
feebly nitrated cellulose (collodion-cotton) only, and the highly nitrated cellulose
(cotton-powder) only so far as the feebly nitrated cellulose is present therein. The
highly nitrated cellulose is therefore left for the most part in its original form and
unaffected by the further stages of the manufacture gives the powder-flakes the
desired non-homogeneous loose and open structure and a rough surface.
In the process according to the present invention the incomplete gelatinization of
the nitro-cellulose has only for its purpose to give the powder flakes to be
manufactured a loose structure and a rough surface and to allow a rapid and more
complete elimination of the solvent; but to obtain a larger volume an entirely new
method is employed.
A crumpled or curved corrugated form is given to the individual powder flake
and this is effected essentially by making the flakes proportionally large and thin,
so that in the drying process which must be carried out with the utmost possible
rapidity they easily warp and become crumpled.
The manufacture of the powder may be explained by the following example:
The powder paste is made of say 20 per cent. of highly nitrated collodion cotton,
this mass is kneaded in the presence of a solvent of the collodion cotton consisting

page_text: of say 66 parts of sulphuric ether and 34 parts of alcohol whereupon it is rolled into
thin bands having a thickness of about 0.1 millimetres; these bands are then
cut into flakes having proportionally to their small thickness a large surface
say 1.8 x 1-8 millimetres, and finally they are dried as rapidly as possible.
By the incomplete gelatinization, in lieu of the smooth surface of the former 5
powders, a rough surface is produced, moreover owing to this roughness and the
small thickness of the flakes the solvent in the rapid drying process vaporises
quickly and completely, whereby again in combination with the proportionally
large surface flakes of a corrugated curved or crumpled form are produced.
The flakes obtained by the combination of several different partly known 1
methods have a new particular shape, so that they do not lie closely side by side
or one above the other, but are loosely piled up occupying thus a space, which is
larger or at least as large as the space, which would be occupied by a quantity of
black gunpowder exerting the same power in the fire-arm.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
A process for producing a smokeless bulky powder of loose structure consisting
in preparing a powder-paste of incompletely gelatinized nitro-cellulose produced
according to one of the known methods of manufacture rolling the paste into thin
bands of 0.1 millimetres thickness cutting these bands into flakes having in
proportion to their small thickness a large surface, and drying the flakes as rapidly
as possible whereby a crumpled or curved corrugated form and a rough surface is
given to the individual flake substantially as described.
Dated this 5th day of October 1894.
W. P. THOMPSON & BOULT,
London, Nottingham, Liverpool, Manchester, Agents for the Applicant.