Process for the production of a thermal shock tube, and the product thereof

Abstract

A process for the production of a thermal shock tube is used to form a product that is utilized as a transmission device for connecting and initiating explosive columns, or as a flame conductor. The device is usually complemented by a delay element or used as a delay unit. The thermal shock tube uses a pyrotechnic mixture with low sensitivity to ignition by shock or friction, with low toxicity, and which generates a spark with superior thermal performance. The process utilizes continuous and separated dosing of the individual non-active components, in conjunction with the formation of the plastic tube, making the process safer, and with a more accurate dosing. The product maintains the advantages of current art pyrotechnic shock tubes relative to the shock wave propagating tube, e.g. larger transmission sensibility and sensitivity, propagation even with cuts or holes in the tubes, and low risk transport classification. The product has the additional advantages of using low toxicity components, use of ordinary, low cost, low adhesiveness polymers, the generation of a spark that propagates through knots, closed kinks or tube obstructions, and resistance to failure due to attack of components by hot explosive emulsions.

1 . A shock tube comprising: 
 an outer tube formed by extrusion, with an interior region containing a pyrotechnic mixture, said pyrotechnic mixture comprising an oxidizer, a reduction agent, a substance with a low temperature of Tammann, and an adherence promoter.    
   
   
       2 . The shock tube of  claim 1  wherein: 
 said pyrotechnic mixture comprises 32-60% oxidizer, 15-35% reduction agent, 20-40% substance with a low temperature of Tammann, and 0.5-3.0% adherence promoter.    
   
   
       3 . The shock tube of  claim 1  wherein: 
 said oxidizer is from the class of powdered ferrous oxide, ferric oxide, cobalt oxide, cuprous oxide, and cupric oxide.    
   
   
       4 . The shock tube of  claim 1  wherein: 
 said adherence promoter is from the class of talc and graphite.    
   
   
       5 . The shock tube of  claim 1  wherein: 
 said desensitizing agent is from the class of potassium perchlorate, potassium chlorate, ammonium perchlorate, sodium perchlorate, sulfur, and antimony trisulfide.    
   
   
       6 . The shock tube of  claim 2  wherein: 
 said oxidizer is from the class of powdered ferrous oxide, ferric oxide, cobalt oxide, cuprous oxide, and cupric oxide.    
   
   
       7 . The shock tube of  claim 2  wherein: 
 said adherence promoter is from the class of talc and graphite.    
   
   
       8 . The shock tube of  claim 2  wherein: 
 said desensitizing agent is from the class of potassium perchlorate, potassium chlorate, ammonium perchlorate, sodium perchlorate, sulfur, and antimony trisulfide.