An Improved Manufacture of Explosive Compounds.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
An Improved Manufacture of Explosive Compounds.
I, ALFRED NOBEL, Chemist, Doctor of Philosophy, of 59 Avenue Malakoff, Paris
in the Republic of France, do hereby declare the nature of this invention to be as
follows:
This invention relates to the manufacture of a smokeless explosive compound,
consisting of layers of different chemical compositions, which are of such a nature,
and are so arranged that the combustion is slowest in the outer layer, and increases
inwards. The object of this invention is to modify the pressure in the powder.
chamber and adjacent parts of the guns in which the explosive compound is used,
which pressure has a tendency to rise to a dangerous point, owing to the charge
being confined in a contracted space.
I am aware that it has been tried to impart a progressive combustion to ordinary
black powder by using, in the outer layers of the same, saltpetre crystals of
larger size than in the inner layer; but in this way the desired result will not be
obtained, owing to the fact that the larger crystals make the product more porous,
and thus, as it is well known that the quickness of combustion of powder increases
with the porosity of the same, it will easily happen that a result is obtained which
is contrary to the one sought for. As a proof of the correctness of this statement,
it might be mentioned that, by strong compression, it has been possible to make
pieces of finely comminuted ordinary black powder of such a slow combustion that
when ignited, it could be extinguished.
The explosive compound manufactured according to this invention differs
essentially from the above mentioned powder, in that its progressive quality is
obtained, in the latter case, in a purely mechanical way, by altering the size of the
saltpetre crystals, while in the former case it is obtained in a chemical way, by
introducing chemical substances in the outer layers of the compound, capable of
modifying its explosive character.
In carrying out this invention, I use what is called ballistite, or an analogous
explosive which is of such character that, during some stage in the manufacture,
it is in a plastic state, and can then be pressed or rolled into any desired shape.
The manufacture itself may be varied according to the nature of the explosive,
the form it is desired to give the same, the ballistic properties of the fire-arm, the
purpose for which it is intended, and the like. A few examples may be given
in order to explain the way in which this manufacture is carried out. Of the
different forms that may be given to this explosive, I may mention that of cakes
or of tubes.
Charges in the form of cakes, which are specially suitable for large guns, are
obtained by providing a thick rolled leaf or sheet, say A, of a composition of quick
combustion, and two thinner rolled leaves, say B, of a slower burning composition.

page_text: These leaves B are then placed one on each side of the leaf A, whereupon they are
all rolled together or pressed in a heated state, or connected together by applying
a suitable solvent, for instance, a solution of collodion in acetate of amyle, upon
the surfaces, which are to be in contact with each other.
Charges in the form of tubes may be produced in same way as is usual for
ballistite and similar kinds of explosive, only with the difference that the nozzle
of the apparatus used in producing the tubes is arranged for simultaneously
squeezing out several concentric layers of different compositions which, owing
to their plasticity, will appear as only one coherent mass.
The following compositions will give good results :--
For A (the inner layer):-
60% Nitroglycerine
40% Nitrocellulose (of, for instance, 12% of nitrogen).
For B (the outer layer):
45% Nitrocellulose
45% Nitroglycerine
10% Succinate of amylic oxide, or phthalate of methylic oxide, or any one
of the many known non-explosive substances, or compositions of such substances,
which dissolve nitrocellulose, and have, besides, a high boiling point, in order not
to evaporate, as the properties of the explosive would then be altered. Such
substances may be substituted the one for the other, as they all serve the same
purpose, viz., to modify the rate of combustion of the explosive.
For large guns, it is preferable to manufacture the charge by using several layers
having various rates of combustion, which increase towards the centre of the
charge. Thus, the innermost layer will consist of a composition of quick combus-
tion, intermediate layers of slower combustion, and outer layers of very slow
combustion.
The advantages obtained by the use of charges thus prepared are:-
1. The possibility of using a great density of the explosive material, whereby
the size of the cartridge, and thus also the size of the chamber, will be reduced to
a minimum.
2. A lowering of the maximum pressure, whereby the strain on the breech, and
on the hind portion of the gun, will be diminished, & erosions prevented to a great
extent.
3. A greater effect per unit of weight of the barrel.
Dated this 30th day of November 1900
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Manufacture of Explosive Compounds.
We, RAGNAR SOILMAN of Bofors, and RUDOLF LILJEQUIST, of 31 Malmskilnads-
gatan, Stockholm, both in the Kingdom of Sweden, Executors of the will of the late
Alfred Nobel, Chemist and Docter of Philosophy, of 59 Avenue Malakoff, Paris,
in the Republic of France, do hereby declare the nature of this invention and in
what marner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to the manufacture of a smokeless explosive compound,
consisting of layers of powder of different chenical compositions, which are of such

page_text: surfaces of the coils. The rolls thus formed may be of any desired length, and,
when a heavy charge is required, it will se convenient to fill the cartridges with
short rolls of corresponding diameter, placed one upon the other.
Charges for rifles may be produced in the form of tubes, in the same way as is
usual for ballistite and similar kinds of explosive, only with the difference that the
nozzle of the apparatus used in producing the tubes, is arranged for simultaneously
squeezing out several concentric layers of different compositions, which, owing to
their plasticity, will appear as only one coherent mass.
The following compositions have been found to give good results:-
I. For (the inner layer):-
60% Nitroglycerine
40% Nitrocellulose (of, for instance, 12% nitrogen)
For B (the outer layer):
45% Nitrocellulose
45% Nitroglycerine
10% Succinate of amylic oxide or phtalate of methylic oxide, or any one of
the many non-explosive substances, known as 'moderants," or compositions of such
substances, which dissolve nitrocellulose, or can be otherwise incorporated there-
with, and have, besides, a comparatively high boiling point, in order not to
evaporate, as the properties of the explosive would then be altered. Such sub-
stances may be substituted the one for the other, as they all serve the same purpose,
viz., to modify the rate of combustion of the explosive.
II.
For A:-
Same as above.
For B:-
90% of composition A
10% of powdered starch or sugar, or analogous solid or semi-solid
substances, rich in carbon and hydrogen.-
III. For A:-
80% of ballistite of following composition:-
50% Nitroglycerine
45% Nitrocellulose
1
5 Succinate or amyle or other aforesaid solvent or moderant.
20% highly nitrated wood meal, or pulverized Nitrocellulose of any other
description.
For B:-
Ballistite of the same composition as for A, but without the aforesaid
addition of Nitrocellulose.
For large guns, it is preferable, in manufacturing the charge, to use a greater
number of layers, with various rates of combustion, increasing always towards the
centre of the charge. Thus, the innermost layer will consist of a composition of
very quick combustion; intermediate layers of slower combustion; and outer layers
of very slow combustion.
The advantages obtained by the use of charges thus prepared are:-
1. The possibility of using a great density of the explosive material; whereby
the size of the cartridge, and consequently of the powder chamber, will be reduced
to a minimum.
2. A lowering of the maximum pressure, whereby the strain on the breech,
and on the hind portion of the gun, will be diminished, and errosions prevented to
a great extent.
3. A greater effect per unit of weight of the barrel.
Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
The manufacture of explosive compounds as above described, consisting in
placing upon each other, by pressing, rolling, or otherwise joining together, layers

page_text: a nature, and are so arranged relatively to each other, that the combustion is
slowest in the outer layer, and increases inwards. The object of this invention is
to modify the pressure in the powder chamber and adjacent parts of the guns in
which the explosive compound is used, which pressure has a tendency to rise to a
dangerous point, owing to the charge being confined in a contracted space.
Attempts have been made to impart a progressive combustion to ordinary black
powder, by using in the outer layers of the same, saltpetre crystals of larger size
than in the inner layer, but in this way the desired result will not be obtained,
owing to the fact that the larger crystals make the product more porous, and as the
quickness of combustion of powder increases with the porosity of same, it will easily
happen that a result is obtained which is contrary to the one sought for. As a
proof of the correctness of this statement, it might be mentioned that, by strong
compression, it has been possible to make pieces of finely comminuted ordinary
black powder of such a slow combustion, that when ignited it could be extinguished.
It has also been proposed to obtain the effect of progressivity by coating part of
the grain with a comparatively slowly combustible material, in order to product
an increasing burning surface from the non-coated parts of the grain; but besides
the inappropriateness of introducing into the powder chamber another materia
than powder, even if comparatively rapid of combustion, this manufacture has
the inconvenience of producing gases of the highest temperature at the commence
ment of ignition. In the firing of explosives made according to the present inven
tion, the gases produced at first are of a comparatively low temperature, as the
substances apt to lessen the velocity of combustion, also tend to lower th
temperature of the gases produced. This is of great consequence in respect o
protecting the bore of the gun from erosion, for, with the high pressure during the
first moments of combustion, any increase in temperature greatly increases th
danger of erosion..
The explosive compound manufactured according to this invention differs essen
tially from both of the above mentioned powders, in that the progressive quality
is obtained, in the black powder in a purely mechanical way by altering the siz
of the saltpetre crystals, and in the coated powder also, by a mechanical arrange
mont, viz., by limiting the surface to be ignited, in order to obtain a spreading fire
i.c., an increasing burning surface, while in the case of the present invention, i
is obtained in a chemical way, by introducing chemical substances in the oute]
layers of the compound, capable of modifying its explosive character.
In carrying out this invention, the material preferably used is ballistite, or at
analogous explosive, which is of such character that, during some stage of the
manufacture, it is in a plastic state, and can then be pressed or rolled into any desire
shape. The manufacture itself may be varied according to the nature of the
explosive, the form it is desired to give the same, the ballistic properties of the fire
arm, the purpose for which it is intended, and the like. A few examples may be
given in order to explain the way in which the manufacture is carried out. Of the
different forms that may be given to this explosive, two examples may suffice, viz:
sheets and tubes.
Charges in the form of sheets, which are specially suitable for large guns, art
obtained by providing a thick rolled leaf or sheet, which may be called A, of 1
composition of quick combustion, and two thinner rolled leaves, called B, of
slower burning composition.-These leaves B are then placed one on each side of
the leaf A, whereupon they are all rolled or pressed together in their plastic state
or joined together by applying a suitable solvent or glue, as, for instance, a solution
of collodion in acetate of amyle or acetone, upon the surfaces, which are to be in
contact with each other.
The sheets thus prepared are coiled up into the form of rolls of a diameter suit-
able to the cartridges to be filled. The coils of these rolls are kept apart by means
of longitudinal strips of the like material, the object of the insertion of these
strips being to form conducting passages for the fire from the fuse to act upon the

page_text: of a plastic explosive compound of different chemical composition, as respects rate
of combustion, in the order and for the purpose above set forth.
Dated this 30th day of August 1897
NEWTON & SON,
Agents for the Applicants.