Gun powder is a propellant for Feuerwaffen and solid-propellant rockets, which consists contrary to the black powder used in former times of the so-called smoke-weak cellulose nitrate powders. Instead of the designation coming historically from the black powder "gun powder "is today usually used the term propellant powder. These belong together with the initial explosives, explosives, black powders, igniting mixtures and pyrotechnic sentences to the explosives.
Were developed the smoke-weak gun powders at the end 19. Century, when that did not meet the requirements of modern artillery weapons up to then mainly as propellant used black powders any longer. For the use in large-caliber cannons black powder was a little suitable, because it was too offensive: The propellant was burned down already, before the projectile had reached the tube end, and caused so a strongly rising Druckkurve. Attempts, the burn-up rate first by rougher granulation of the black powder to reduce thereafter by higher compression of the raw powder mass showed only limited successes. Further disadvantages were the strong smoke development and the strong contamination of the pipes by salts, which develop with the burn of black powders. Thus a kilogram of black powders produces about 600 gram salt mixture, mainly potassium sulfite and potassium carbonate with the burn. The salt contamination particularly prepared problems with rifles (with those the of the black powder did not disturb) and was hinderlich with the transition to smaller calibers. After little successful attempts on the basis of potassium spades advice and a mixture of potassium chlorate, prussiate of potash and sugar attempts began with nitrated cellulose. This developed hardly smoke and left no arrears, was too offensive however also with rifles. Remedy found by the Gelatineren with different solvents and the Phlegmatisieren. By the applied Gelatinierungsverfahren, variation of the additives as well as size and form of the powdering hurry could be affected now the combustion behavior to a large extent, however the smoke development increased and the powder burned no longer completely arrears-free by the used additives. That was taken however due to the other advantages in purchase.
According to the composition the gun powders are divided in three classes:
Pole powder (powder without [organic] solvents) two or dreibasige propellant powders for artillery are called or also as rocket fuels. The Gelatinierung and the homogenization take place with water via rolling, extruding or snail press processes, whereby Diethylenglykoldinitrat or Glycerintrinitrat functions as "solution and source means "for nitrocellulose. Then the water up to approximately 1 % one evaporates and one forms by machine afterwards the powder.
For the so-called tropical powders in Germany because of the smaller evaporability Triethylenglykoldinitrat was used instead of Diethylenglykoldinitrat. Glycerintrinitrat was only limited available during both world wars because of the scarceness at fats and oils as raw material.
The finished powders are graphitiert, in order to thus avoid static loading during pouring and sparking.
For the decrease of the smoke development and increase of the stability in storage 0.5 % to 2 % diphenylamine can be admitted.
An additive of 1 % sodium oxalate or 2 % potassium sulfate prevents the inflammation of the flue gases and thus muzzle lightning.
Dinitrotoluol can be used as replacement for Glycerintrinitrat or Diethylenglykoldinitrat, is however importantly more poisonous. For the same purpose also Ethylenglykoldinitrat can be used, however a slow separation takes place because of the much lower boiling point by evaporation and back condensation. Therefore this powder is not for a long time storable.
When replacement for nitrocellulose know up to 50 % nitrate of ammonia are admitted, however the gun powder is then moisture-sensitive. Presslinge from coal dust and nitrate of ammonia became in the 1. and 2. World war used in Germany as propellants for the artillery.
According to the form one differentiates tubular powders, disk powders, Streifenpulver, ring powders, noodle powders and other forms. The form and size of the powdering hurry by the size and form of the propellant as well as the desired burn-up profile one determines to a large extent. In large-caliber cannons one uses tubular powders, in high-angle fire cannons disk powders, in hand-held weapons mainly fine-grained powder propellant charges for rockets in form of cylindrical Presslinge is mostly manufactured, which receive additionally drillings and grooves for the enlargement of the burn-up surface.
In order to prevent to deflagrieren that an artillery propellant detonated instead of, it is ignited these not directly by the Initialladung, but over a black powder intermediate charge. Thus also the even ignition of the total load is guaranteed.