GB787411A - Improvements in or relating to the manufacture of plastic incendiary materials - Google Patents

Abstract

787,411. Plastic incendiary materials. IMPERIAL CHEMICAL INDUSTRIES, Ltd. Feb. 22, 1956 [June 8, 1955], No. 16436/55. Class 9(2) Extruded incendiary cords comprising a thermoplastic binder and oxidizing and reducing agents are prepared by making separate admixtures of the binder and the reducing agents and of the binder and the oxidizing agents, forming an intimate admixture by feeding the two kinds of thermoplastic mixtures into a heated extrusion machine of the worm type, and then extruding. Preferably the admixture is formed from one thermoplastic mixture containing all the oxidizing agents and one thermoplastic mixture containing all the reducing agents. These mixtures, which may be reduced to chip form, are preferably fed as separate streams into the heated extrusion machine. When the mixtures are in chip form remote control may be adapted for the extrusion process to increase the safety of the operator. In examples, the cylinder of the extruder is heated to approximately 70‹C. and the extrusion head to 100‹C., the reducing,mixture is silicon in the same binder as the oxidizing agent and (a) the oxidizing mixture, (b) the core round which the cord is extruded, (c) the covering, (d) the burning speed are as given:-(1)(a) red lead and potassium chlorate in plasticised nitrocellulose plus diethyl centralite, (b) copper wire, (c) polyethylene, (d) 36 sec./yd.; (2) (a) lead dioxide and potassium per- .chlorate in a 60:40 polystyrene : dibutyl phthalate plastic, (b) copper wire, (c) polyethylene, (d) 44 sec./yd. (3) (a) lead dioxide in 40:60 methyl methacrylate : dibutyl phthalate plastic, (b) copper wire, (c) polyethylene, (d) 60 sec./yd.; (4) (a) red lead and potassium nitrate in plasticised nitro-cellulose plus diethyl centralite, (b) a semi-cord consisting of paper yarns coated with a mixture of nitrocellulose dope in acetone and fiely ground plack-powder and bound with cotton, (c) polyethylene, (d) faster than 1 sec./ft.; (5) (a) red lead and potassium nitrate in plasticised nitrocellulose plus diethyl centralite, (b) glass yarn, (c) polyethylene followed by a covering of jute yarns which are then coated with bitumen and finally polyethylene, (d) 150 sec./yd.