Solventless powder

P.O.L. Ger acronym for Pulverohne Losung, which means Solventless Powder... 

Solventless powder without nitroglycerine (G powder, p. 660) has a lower heat of explosion, and consequently causes less wear on the bore. 

Nitroglycerine powders can be classified into two groups with and without a volatile solvent. Semi-colloidal nitrocellulose powders and nitroglycerine solventless powders are the most important types of smokeless powder. 

Powder with a low content of nitroglycerine is simply called solventless powder to distinguish it from ballistite. 

Solventless powder is usually tubular. It was first produced at the Diineberg factory, in 1912, under the name of RPC/12 (Rohrenpulver mit Centralit 1912). Initially the manufacture of this powder was based upon the use of easily soluble nitrocellulose (11 % N), plus guncotton to bring the total nitrogen content up to 11.7%. About 25% nitroglycerine was used plus a large quantity of centralite (4-5%) as a non-volatile solvent. 

After World War I the manufacture of solventless powder was started in other countries France under the name of powder SD (sans dissolvent), Great Britain as Cordite SC (solventless cordite) and the U.S.S.R. 

According to Wheeler, Whittaker and Pike [37] British solventless powder consisted of ... 

In the U.S.S.R. a type of solventless powder was introduced in which organic nitro compounds, e.g. DNT, partly replaced the nitroglycerine. DNT acts as a non-volatile solvent and as a stabilizer. Since it also reduces the heat of explosion these powders are either flashless or partly so. 

Two operations in the manufacture of solventless powder are of particular importance ... 

Rolling. The paste intended for the manufacture of solventless powder is first rolled between drying rollers (at 50-60°C) and then between gelatinizing rollers, as in the manufacture of ballistite. This operation must be very carefully controlled. 

The causes of explosions during the pressing of hot, solventless powder have not yet been fully explained. They may include discharge of electricity accumulated... 

The mechanism of the pressing process should be known in great detail in order to recognize the dangerous moments. Fleury [38] investigated the pressing of solventless powder, and recorded the following ... 

Recently a new technique of extrusion of solventless powder dough was introduced, in which extrusion is effected by a worm screw extruder instead of a hydraulic press. 

THE MANUFACTURE OF SOLVENTLESS POWDER IN GERMAN FACTORIES [42J Notation... 

Tavernier Prache (Ref 2) investigated the compressibility/ of French solventless powders (poudres SD) and ofl Ballistites. Their shrinkage was only 3-4% at pressures up to 3000 kg/sq cm. This value is considered.sufficiently small so as not to affect the calculation of vivacity of propints. See also Ref 4... 

Solventless Powder. See under Cannon Powder (Propellants) in Vol 2, C33-R, and Propellants, 50110 in VOl O, rwj-ato rHUo-x anti... 

High exposures remained eommon in paint and printing ink industry still in 1970 s for example, most solvent measurements eondueted in these industries in Finland exeeeded the present OELs. Water-based paints are today elearly most eommon in eonstmetion painting. Alkyd-based eonstmetion paints with white spirit (Stoddard solvent, mineral spirit or solvent naphtha) as a solvent are, however, still produeed. Solvent-based paints have remained most eommon in industrial painting, even though the solventless powder paints are also produeed in large quantities. 

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