Effect of Explosive Impact on Ignition Head Damage and Ignition Time of Electronic Detonator

In order to study the effect of explosion impact on the damage and ignition time of the ignition head of the electronic detonator, the lead thiocyanate ignition agent was prepared and its microstructure was observed, and the ignition voltage of the ignition head sample dipped in was measured to test its quality. The underwater explosion method was used to impact the sample detonator without basic charge, and the damage of the ignition head was observed by disassembling the impact detonator, and the high-speed schlieren system was used to carry out the ignition test on the ignition head without obvious damage. The results show that the ultimate pressures of the unguarded, heat-shrinkable and silica gel ignition heads were 98.22, 117.12 and 156.27 MPa, respectively. The three types of protection ignition heads were damaged to varying degrees above the ultimate pressure. Under the wall thickness of 0.38 and 0.50 mm, the explosion miss-fire rate of the three types of protective ignition head showed a trend of decreasing with the decrease of impact strength, and the protective effect of silicone type was better than heat shrinkable type, and the effect of non-protective type was the worst. Under 98.22 MPa, the high pressure gas causes the fragments of the ignition head to fly away, resulting in the reduction of the quality of the ignition head used for ignition, the reduction of the intensity of ignition, and finally the obvious shortening of the ignition time. The ignition time of the heat-shrinkable ignition head at 117.12 MPa was increased by 8.30% compared with no impact, which may affect the delay accuracy of the electronic detonator. The ignition time of the silicone ignition head at 156.27 MPa was almost unaffected.