Ball powder

Table 9. Composition and Properties of Ball Powder Propellants...

Fig. 8. Ball powder batch process. NC = nitrocellulose, EA = ethyl acetate, DPA = diphenylamine, NG = nitroglycerine.

The US Air Force has studied the encapsulation of liq monoproplnts such as alkyl nitrates in polymer films to form small spheres much like ball powder for use as gun proplnts (Refs 6, 8 9). Suspension coating techniques were used, and microcapsules were made with gelatin,... 

A free-flowing "ball powder containing 60—80 wt percent of liq monoproplnt was obtained and successfully fired in small arms cartridges. There were serious difficulties with permeation of the volatile liquids thru the capsule walls and with ignition of the smaller capsules... 

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... 

Ball Powder was developed by Fred Olsen of Olin Mathieson Chemical Corp (Vol 2 of Encycl, pp B11 —B16)... 

The key to the successful application of high performance, pourable nitrocellulose plastisols lies in a reasonably priced, high quality source of fine-particle, at least partially colloided, spheroidal nitrocellulose. Here we are speaking of particles much finer than the well-known ball powder, produced by the Olin Mathieson Chemical Co. for small arms for over 30 years (7). Actually, particles on the order of 5-50/x diameter appear to be required to assure a reasonable continuum of uniformly plasticized nitrocellulose binder in a propellant containing 45% or more of combined crystalline oxidizer and powdered metal fuel. Such a continuum of binder is necessary to assure acceptable mechanical properties and reproducible burning characteristics of the finished propellant. Preincorporation of a certain content of the water-insoluble solids within the nitrocellulose microspheres is an effective means of helping to assure this continuum of binder and alleviates the requirements for extremely small ball size. The use of a total of 45% or more of crystalline oxidizer and (generally) metal fuel is essential if the propellant is to be competitive with other modern propellants now in service. 

Fig. 253. Cross-section of a ball powder grain magnified 300 times. The light ring on the outside indicates the location of the gelatinizer (phlegmatizer). (Courtesy Olin...

Olin Industries report that no fatal accident attributable to ball powder has occurred in twelve years of manufacture, during which time more than 60,000,000 lb of ball powder have been produced. Labour requirements are low ball powder can be manufactured by using fifty man hours per 1000 lb of finished powder as compared with 125-200 man hours per 1000 lb required by the conventional process for making extruded powder. 

DOUBLE-BASE AND TRIPLE-BASE PROPELLANTS. A description of double-base proplnts containing NC + NG was given in this Encycl under BALLI5TITE (Vol 2, pp B8-L to B10-L), under CANNON PROPELLANT Vol 2, pp C33-L to C37-L) and under CORDITE (VoL 3, PP C531-L to C541-R). Some Ball Powders, described in Vol 2, pp Bll-R to B16-L can be made double-base. The description did not include the German proplnts which were described previously in Refs 1, 2 3 and in Ref 4, pp Get 142 (Table 43) Ger 146 (Table 46), under PROPELLANT (Treibmittei)... 

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

Note If for some reason it is not desirable or convenient to roll the ball powder, the equal time of burning of sm all and large grains may be approx achieved by surface-treating the larger grains with an accelerator such as NG) and the slower grains with a very slow deterrent, such as some phthalate... 

Following are some advantages in the manuf of ball powder over conventional propints ... 

J.J.O Neil,Jr Ordn 41,365-7(1956)(Manuf of ball powder by Olin Mathieson Chemical Corp)... 

W.A.Schmelling,Badger Ordnance Works, TechReptNo 176(1957) (Reclamation of NC and NG from scrap double-base proplnts for use in ball powder manuf) 18)J.H.Herd,Naval Ordnance Lab. NavOrd Rept No 6I31(1958)(Approval of ball powder type WC-860 for use in the explosive actuator MK 4 MOD O) 19)J.J.O Neil G.R.Cox, USP 2830886(1958) (A process for the manuf of globular proplnt) 20)R.L.Cook E.A.Andrew,... 

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