LOW-POWER PRIMER AND METHOD OF ITS MANUFACTURE Russian patent published in 1999 - IPC

FIELD: blasting. SUBSTANCE: low-power primer has a plastic tube with a channel made up at least of two layers of plastic material. The first layer is positioned closer to the channel, and the other one-outside the first layer. The tube channel accommodates an active material maintaining the shock wave in the channel after ignition. At least the second layer of the tube has the main part of polymer resin axially oriented by expansion to a degree of orientation of more than 20% and less than 90%. The degree of axial orientation of polymer of the first layer does not exceed the degree of orientation of the second layer by more than 10%. The first layer is formed as a tube by extrusion of plastic material of this layer. Active material is introduced into the tube channel. Then restricted expansion of the first layer of the tube is effected for imparting a degree of orientation of not more than 10% to it. The second layer of the tube is formed around the first layer by extrusion of plastic material of the second layer at a low degree of orientation of the first layer. Then cold expansion of the first and second layers together is accomplished. EFFECT: enhanced axial and radial strength characteristics of primer tube, whose inner layer serves to provide radial strength, and the outer layer provides axial strength. 71 cl, 7 dwg, 3 ex