GB544252A - Improvements in or relating to the manufacture of non-detonating fuzes for blasting and similar purposes - Google Patents

Abstract

544,252. Blasting fuzes. CALDWELL, W. A., WHITE, A. G., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. July 1, 1940, No. 11091. [Classes 9 (i) and 9 (ii)] A non-detonating fuze for blasting comprises a deflagrating mixture of oxidizing and reducing agents bound together by a non-volatile non- detonating binding material of nitro-cellulose having colloidal properties but free from nitroglycerine so as to form a paste which is extruded from a press through a die to form an imperforate core, which is enclosed in an envelope of less combustible or incombustible material. A soft fine metal or alloy wire may be incorporated in the core. The paste is fed from a chamber which may be heated through a jacket 4 by a screw feed 2 into a chamber having a die 6 at its outlet while threads of textile material and wire 8 are fed through a guide 7 and the die at the same rate so that they are surrounded by the paste. If a volatile solvent is used for the binding material this is allowed to volatilize before the core is covered. If the protective coating for the core is to be of yarn this is spun directly on the core as it emerges from the extrusion press and the yarn is rendered waterproof by a coating glue, gelatine, casein, cellulose, dextrin, agar-agar gum arabic, or asphalt, tar, bitumen, resins or rubber. The oxidizing reducing deflagrating mixture is formed of nitrate, oxides, permanganates, chlorates, chromate, and oxidizable metals and alloys, silicides, charcoal and the like. Examples given are:- (1) a mixture of potassium nitrate and charcoal with a syrup of low viscosity nitrocellulose with dinitrotoluene isomers ; (2) a mixture of triphembic tetroxide with calcium silicide and syrup as before; (3) a mixture of potassium nitrate with charcoal and industrial nitrocelluse in acetone; (4) a mixture of potassium nitrate with charcoal and industrial nitrocellulose in dibutyl phthalate; (5) a mixture of triphembic tetroxide with calcium silicide and charcoal and syrup of industrial nitrocellulose and dibutyl phthalate.