The Chemistry of Powder and Explosives - Sciencemadness Dot Org

NITROCELLULOSE 261
nent materials which are prone to decompose with the formation
of acid.
The preliminary boiling or sour boiling is carried out in large
wooden tubs heated by means of steam. At the beginning the
nitrocellulose is boiled with water which contains 0.25% to 0.50%
FIGURE 62 Nitrocellulose Fibers before Beating (132X) (Courtesy Western
Cartridge Company )
of acidity calculated as sulfunc acid. The first boil lasts usually
for 16 hours during which time the acidity of the solution increases.
The increase is due largely to actual sulfunc acid. After
16 hours the steam is shut off, the solution is decanted from the
nitrocellulose, the tub is filled with fresh water, and the material
is boiled again for 8 hours The boiling is repeated until each
tubful has been boiled for 40 hours with at least 4 changes of
water