Nitrocellulose powder manufacture

The drying of powder was formerly one of the most hazardous operations, but since the causes of danger have been eliminated by new methods it is now no more dangerous than any other of the processes for manufacturing nitrocellulose powder. The following rules must always be observed ... 

In Russia, Mendeleyev [12] worked out a method for the manufacture of smokeless powder from pyrocellulose, i.e. relatively high-nitrated (12.5% N) nitrocellulose soluble in a mixture of ether and alcohol. In 1892 the manufacture of this powder was started for naval guns. Nitrocellulose powder of this type was soon adopted for military purposes in the U.S.A., where nitrocellulose powder became known as single base powder . 

In the manufacture of nitrocellulose powders the water is displaced with alcohol. This method was proposed by Lundholm and Sayers [3] and widely used in many countries [4, 5]. Despite the simplicity of the idea the dehydration process is rather complicated. It is influenced by such factors as the solubility of nitrocellulose in alcohol and the ability of nitrocellulose to swell under the influence of alcohol the lower the solubility of nitrocellulose in alcohol, the more easy dehydrated with alcohol. Since, however, the solubility of nitrocellulose depends primarily on its nitrogen content dehydration is easier with the higher nitrated types of nitrocellulose. 

Nitrocellulose for the manufacture of powder must meet requirements of chemical stability, nitrogen content and solubility in a mixture of alcohol and ether according to the regulations discussed in the chapter on nitrocellulose. 

For the manufacture of nitrocellulose powder a volatile solvent is used, i.e. a mixture of alcohol with ether in a weight ratio of about 2 1. 

Ether, in its common commercial form, is sufficiently pure to be used in admixture with alcohol. Its acid content should not exceed 40 mg (calculated as H2S04) per litre, nor should it contain nitrites. A nitrocellulose powder plant must include a plant for the manufacture of ether. 

In France, two types of an alcohol-ether mixtures are used for the manufacture of nitrocellulose powder specified in terms of Baume degrees ... 

Solvent escapes from nitrocellulose powder at various stages of its manufacture. The largest amount volatilizes during the predrying of the freshly shaped strips or tubes in cabinet driers specially constructed for this purpose. Installations for the recovery of this solvent have therefore long been in use in factories. 

Soaking the powder. It appears that the final removal of solvent by soaking ( bathing ) was first applied by Sukhinskii [19] in Russia, in 1892. By this method the solvent is removed from the powder much more rapidly than by any other. Soaking was widely practised in the manufacture of nitrocellulose powders during World War I, since it considerably accelerated production. The soaking temperature was then 80 or even 90°C which was inadvisable for three reasons ... 

The soaking of nitrocellulose powder in which alcohol and ether were used as a solvent should be carried out so that the solvent (chiefly alcohol) which passes into aqueous solution may be recovered. Nitroglycerine powder manufactured with a volatile solvent such as acetone should never be soaked since water would remove some of the nitroglycerine from the powder. 

Between 1936 and 1940 Olsen etal. [27] designed a process for the manufacture of nitrocellulose powder in the form of uniformly shaped balls (Fig. 250). The manufacturing process at Western Cartridge Co., Division of Olin Industries, Inc. at East Alton, Illinois, U.S.A. has been described by Olive [28]. 

As with nitrocellulose powders the manufacturing proc M of nitroglycerine powders described below should be regarded as examples of typical methods which may vary from one country to another. As before, the author has endeavoured, as far as possible, to draw attention to the differences in methods adopted in various countries. 

In 1886, Vieille placed the art of smokeless-powder manufacture on a real foundation by producing the first thoroughly colloided nitrocellulose powder in the form of square flakes of uniform size and thickness. 

By the summer of 1915, the demand for acetone as a solvent for nitrocellulose in the manufacture of powder and dopes for airplane fabrics liecame so great that both sides began to look for substitutes for bromacetone, with the result that in July, 1915, the Germans introduced brom-... 

The main component of nitrocellulose powders is nitrocellulose, a mixture of guncotton (13.0-13.4% nitrogen) and soluble guncotton (11-13% nitrogen content). To manufacture the powder, the nitrocellu-... 

In 1976 Ainmanii [14) examined nitrocellulose powder manufactured in 1927 and found derivatives of diphenylamine as follc-ws by TLC 2-nitro, 2,2 -, 2,4-, 4.4 -dinitro-, 2,2 ,4-. 2,4,4 -trinitro and tetranitrodiplienylaininc Also trace quantities of A -nitroso-4-nitro and A -iiitroso-4,4 -dinitrodipl cnylaminc were detected. 

Cordite is a double-base powder (NG NC typically 55 37% by weight) with mineral Jelly gelatinized by the action of acetone. The term comes from cords of wood, the source of cellulose used to manufacture nitrocellulose. Ballistite is the United States term for much the same material (NG NC around 40 60% by weight). 

Available Forms. Phthalocyanines are available as powders, in paste, or Hquid forms. They can be dispersed in various media suitable for aqueous, nonaqueous, or multipurpose systems, eg, polyethylene, polyamide, or nitrocellulose. Inert materials like clay, barium sulfate, calcium carbonates, or aluminum hydrate are the most common soHd extenders. Predispersed concentrates of the pigments, like flushes, are interesting for manufacturers of paints and inks (156), who do not own grinding or dispersing equipment. Pigment—water pastes, ie, presscakes, containing 50—75% weight of water, are also available. 

Trinitrotoluene DNT Tetryl Primer materials < s Nitrocellulose j Nitroglycerin 1 j NC-based propellants j Ball Powder j 0> > o PL. -o ra 55 Acid manufacture J Filling of warheads Mfg of extruded rocket grains j Mfg of cast rocket grains... 

Shortly afterwards (1885) Vieille s powder was introduced in France under the name of B powder (Poudre B). Vieille utilized two types of nitrocellulose for its manufacture collodion cotton CP2, soluble in a mixture of ether and alcohol and forming the powder dough cotton CPi, insoluble in a mixture of ether and alcohol, incorporated into the powder mass in the form of unchanged fibres... 

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