Ball-grain 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]. 

A diagrammatic presentation of the process is shown in Fig. 249. The nitrocellulose containing about 13.45% N is stabilized in kiers, cut in beaters and introduced under water into still (7) fitted with a stirrer, containing ethyl acetate with a small amount of diphenylamine (Fig. 251). Calcium carbonate is also added. The presence of water is not harmful when dissolving nitrocellulose in ethyl acetate. Diphenylamine remains in the organic solvent phase (ethyl acetate), thus neutralizing the acid products dissolved in the ethyl acetate, while the calcium carbonate remains suspended in the 

however, the balls are dehydrated before hardening, i.e. before distillation of the solvent, they have a high density. To dehydrate them some sodium sulphate is 

The distillation of ethyl acetate is carried out either by reducing the pressure in the apparatus or by raising the temperature to 77°C (the boiling point of ethyl acetate under atmospheric pressure). 

The distillate (in receptacle (2)) consists of a layer of ethyl acetate plus water and a layer of water in which 8% ethyl acetate is dissolved. The aqueous layer is rectified to recover the solvent. In all, 95% of the ethyl acetate used is recovered from the distillate and recycled for manufacture. 

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Ball-grain powder is an example of a modern powder approaching fully colloidal structure through the use of ethyl acetate. 

Fig. 250. Ball-grain powder, according to Olin Industries, Inc. [29].

The ball-grain powder is then processed in the conventional manner, i.e. being weighed (11), polished and coated with graphite (12), blended in towers (13), similar to those described above (pp. 628-629), and stored (14). 

The gravimetric density of ball-grain powder varies from 0.400 to 0.975. 

Ball powder or ball grain powder 2 B11—B16 ball powder manufacture, advantages 2 BIS... 

Figure 65. Fred Olsen. Has done important work on cellulose and has made many improvements in detonating explosives, high explosives, and smokeless powder in particular, has invented processes for the quick stabilization of nitrocellulose and for the production of ball-grain powder. Chief of Chemical Research, Aetna Explosives Company, 1917-1919 Chemical Adviser, Picatinny Arsenal, 1919-1928 Technical Director, Western Cartridge Company, 1929—.

The process for the manufacture of ball-grain powder which Olsen and his co-workers have devised 26 combines nicely with Olsen s process for the quick stabilization of nitrocellulose to form a sequence of operations by which a finished powder may be produced more rapidly and more safely than by the usual process. It supplies a convenient means of making up a powder which contains non-volatile solvents throughout the mass of the grains or deterrent or accelerant coatings upon their surface. 

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