Screening smoke

Screening smoke Screening systems Screen printing... 

A third screening smoke-type is white phosphoms [7723-14-0] (WP), P (see Phosphorus and THE phosphides), which reacts spontaneously with air and water vapor to produce a dense cloud of phosphoms pentoxide [1314-56-3]. An effective screen is obtained as the P2O5 hydrolyzes to form droplets of dilute phosphoric acid aerosol. WP produces smoke in great quantity, but it has certain disadvantages. Because WP has such a high heat of combustion, the smoke it produces from bulk-filled munitions has a tendency to rise in pillarlike mass. This behavior too often nullifies the screening effect, particularly in stiU air. Also, WP is very brittle, and the exploding munitions in which it is used break it into very small particles that bum rapidly. 

WP was largely used by the Allies in WWI for screening smokes in hand grenades and mortars. 

Screening smokes are generally white because black smokes are rarely sufficiently dense. Signal smokes, on the other hand, are colored so as to assure contrast and be distinct in the presence of clouds and ordinary smoke... 

Chemical. Used for riot control, incendiary, smoke screening, smoke signalling incapacitating purposes Offensive. Used for their blast effect Practice 6 Training. Used for training personnel in use, care handling of service grenades... 

The screening smoke formulations based on HCE-ZnO have some drawbacks like poor screening property at low relative humidity (RH) as the metal halide smoke particles need atmospheric moisture to react and form a smoke screen. However, such smokes are well known for screening purposes and have been found to have IR characteristics also which make them useful in modern day warfare. 

Krone, U. (1990) A non-toxic pyrotechnic screening smoke for training purposes. Proc. 15th Inti. Pyrotech. Sem.,... 

Hopfgarten, F., and Collvin, P. (1985) Studies of IR and visible screening smoke. Proc. 16th Inti. Ann. Conf. of ICT, Karlsruhe, Germany, July 1985, pp. 29/1-29/10. 

McGregor, R.J., and Collins, C. (1989) The use of RP as screening smokes and examination of various forms of encapsulation. Proc. 14th Inti. Pyrotech. Sem., Jersey, Channel Islands, U.K.,... 

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