Thermal Initiation of Non‐Electric Detonators

Cookoff – the concept of heating explosives to ignition – is a useful tool for determining issues that may be related to safely using and storing explosives, and as such, cookoff experiments have been performed on many different materials. All explosive systems require a means of initiation, which is usually a detonator: a device that often contains a sensitive, primary explosive and a more powerful, secondary explosive. Even if the cookoff behaviors of all the individual explosives in an explosive system are known, the behavior of the combined system may be quite different. In this experiment, the cookoff behavior of non‐electric detonators is investigated. It was determined that there was no distinguishable difference between initiating detonators properly or heating them at a rate greater than 10 °C min⁻¹. Heating detonators at rates less than 10 °C min⁻¹ diminished their output.     

The Development and Application of a Pivoted Beam Test Apparatus for Assessing Safety in the Handling of Initiator Devices

Initiator devices contain small quantities of explosives and are therefore capable of causing harm to operators in the event of an accidental initiation. Little information exists on methods for assessing whether initiator devices can be safely subjected to the sorts of forces generated in manual handling. We have therefore undertaken research to quantify such forces and then to design the apparatus to replicate them. Typical forces are those generated in pulp pinch grips and in single finger presses. This paper presents information relating to the design and use of a pivoted beam unit and its use to investigate percussion caps, a conducting composition cap, stab detonators, flash sensitive detonators, electric detonators and stab igniters.     

电雷管刚性引火元件产品质量因素及控制

电引火元件的结构、性能、工艺质量等方面介绍了刚性药头电雷管的产品性能和质量的影响因素及控制。     

Silver Salt of 4,6‐Diazido‐N‐nitro‐1,3,5‐triazine‐2‐amine – Characterization of this Primary Explosive

A new primary explosive, the silver salt of 4,6‐diazido‐N‐nitro‐1,3,5‐triazine‐2‐amine (AgDANT), was synthesized and characterized. AgDANT was prepared with a 97 % yield and characterized by IR spectroscopy, single‐crystal X‐ray diffraction, and DTA. The crystal density of AgDANT is 2.530 g cm⁻³ and the molecule consists of a centro‐symmetric dimer with a high degree of planarity. The intramolecular Ag Ag distance is relatively low (331 pm) and can be considered as a strong argentophilic interaction. AgDANT is non‐hygroscopic and its solubility in water (1.27 mg in 100 mL at 23 °C) is on a similar level of solubility to that of silver azide. The sensitivity of AgDANT to impact is slightly higher than that for MF, sensitivity to friction is the same as for LA, and sensitivity to electric discharge is between that for LS and MF. Initiation efficiency of AgDANT was tested in electric detonators and compared to dextrinated lead azide (initiation efficiency of AgDANT is 40 mg for PETN secondary charge). The thermal resistance of detonators with AgDANT is satisfactory; all detonators were fully functional after exposure at 65 °C (30 d) and 85 °C (2 d).     

High Safety and Reliability Electric Detonator

The entry into force of the REACH regulation implies a modification of the low‐cost detonators manufacturing by finding new substances to replace common primary explosives that contain restricted chemicals. Herein, an alternative solution with a two‐stage electric detonator that contains only secondary high explosive is proposed. It is based on a two steps process, first a combustion, then a shock to detonation transition. This initiator shows high safety level and is compliant with the STANAGs and the REACH regulation. Contrarily to the EBW detonators, it can be initiated using low voltage and low current. Power supply system can be therefore very compact that is of great advantage for designing pyrotechnical train that have to be integrated into small pyrotechnical mechanisms.     

Experimental research on piezoelectric ceramics activating micro-sized thermochemical battery

To verify feasibility of piezoelectric ceramic activating micro-sized thermochemical batteries, it is very necessary to disclose shock pressure and electric output performances of piezoelectric ceramic. In order to simulate piezoelectric ceramic activating micro-sized thermochemical batteries in the bore, shock pressure, and electronic output testing systems for piezoelectric ceramic have been established. And the piezoelectric ceramics composite structural targets are impacted using one-stage light gas gun to load projectile, which is used to simulate the overload of the projectile with piezoelectric ceramics during projectile launching process, and combining with the experimental tests of a military 3# electric fuse head as a firing component in series. In experiments, the composite structural targets (front steel substrate-piezoelectric ceramic-rear steel substrate) are vertically impacted by the cylindrical 2A12 aluminum projectiles. The change rules of shock pressure, output voltage, and current peak values for piezoelectric ceramics are obtained at the different experimental parameters, and the firing conditions of piezoelectric ceramic igniting the military 3# electric fuse heads and ignition paper are presented.     

Laser Initiation of Non‐Primary Explosive Detonators

Aiming to solve the problems caused by primary explosives in traditional detonators, a new kind of non‐primary explosive detonator based on the principle of flying plate detonator is invented. However, in some special circumstances, such as high temperature, strong radiation, strong magnetic field, overload, high‐pressure conditions, the non‐primary explosive detonator cannot work well because of the defects of its usual used initiating method like electric hot wire initiating devices, electric exploding bridge wire initiator, and initiating by a shock‐conducting tube. In this context, initiation by low energy laser is applied to non‐primary explosive detonator. After this combination, the non‐primary explosive detonator performs well in resisting high temperature, high pressure, overload, and electric interference.     

Microwave vs conventional porcelain firing: Macroscopic properties

This paper provides an overview of the macroscopic properties of porcelain tableware fired in a microwave furnace with six magnetrons (each with a nominal power of 900 W) operating at the frequency of 2.45 GHz. The dependence of firing temperature on physical properties such as shrinkage, water absorption, apparent porosity, bulk density, and impact resistance was analyzed. Emphasis is on the differences in the macroscopic properties of microwave and conventionally (gas and electric) fired porcelain. Batches were fired from room temperature up to above the optimum firing temperature (1380°C). Results show similar macroscopic properties for both firing methods, microwave heating required lower firing temperatures (between 1300°C and 1350°C), and shorter processing times (about 70 minutes). The main differences between microwave and electric firing methods occur in a temperature band of 300°C above the porcelain eutectic temperature (close to 1000°C).     

提高电子雷管延时精度的探讨

延时精度是延期雷管最重要的性能之一,主要从电子雷管起爆过程及延期时间分析影响电子雷管延期时间精度的因素。并从理论和实验数据出发,探讨在生产过程中如何降低这些因素的影响,进而提高电子雷管的延期时间精度。     

Electric conductivity of polycrystalline specimens of periclase

Conclusions We determined the electric conductivity of polycrystalline specimens of periclase. With increase in the temperature of primary firing of the periclase, the coefficients of diffusion of MgO diminish, which reduces the degree of recrystallization and sintering of the periclase.The apparent energy of activation of the electric conductivity of magnesia and magnesia-iron specimens depends on the temperature of primary firing of the MgO. With increase in the temperature of primary firing of the periclase, diffusion of the oxides of iron into crystallites of periclase is hindered much more in the sphere of low temperatures of heating of the crystals, and to a lower degree at high temperatures.     

BP神经网络对快烧瓷质砖烧成工况辩识的研究

本文简述了ＢＰ神经网络结构与算法,利用ＢＰ神经网络对实验电炉焙烧瓷质砖的烧成工况进行了辩识实验,取得了较满意的辩识结果,并提出选择辩识参数时应选对烧成工况取关键作用的参数,以提高辩识模型的识别率。     

Non-overlapping of time steps of delay detonators

The user of delay detonators require a number as great as possible of equidistant time steps. In the case of greater time steps this can lead to the danger of overlapping of burning times between two following time steps. To avoid this, a calculation method is presented for the correction of mean combustion periods that surely eliminates the overlapping of burning times. For very precisely working delay detonators an increase in the number of time steps is possible.     

Polyvinylidene Fluoride (PVDF) Gauges for Measurement of Output Pressure of Small Ordnance Devices

Polyvinylidene Fluoride (PVDF) gauges are thin (25 μm) pressure transducers capable of measuring shock pressures up to at least 25 GPa with nanosecond time resolution for impact‐loading conditions. In this work the application of PVDF gauges for measurement of the output pressure from small ordnance devices was investigated. Gauge assembly, firing fixtures, and data acquisition and analysis are described in detail. The gauges were used to record the pressure from impact of flyers accelerated by exploding bridgewire detonators and detonation cord endtips. Consistent peak pressures with standard deviations typically <10% were obtained. The measured pressures were within 10–30% of the pressures calculated from the velocities of the flyers. The peak pressure correlated with the explosive density of endtips prepared with different explosive loading pressures. These results confirmed that PVDF gauges produced by the Bauer process yield consistent results useful for characterizing the output of small ordnance devices.     

ITO陶瓷靶1MPa纯氧1600℃程控烧结电炉的研制

介绍了ITO陶瓷靶烧结工艺用电炉的研制过程，论述了其安全性解决方案，关键材料的选择，压力容器的设计要点。该电炉为国内首台高压纯氧烧结电炉。     

Modern electric furnaces for heat-treatment of ceramic articles and art glass

The enterprise “TermIKS” manufactures a new generation of electric furnaces for mollification and fusing of glass as well as for drying and firing ceramic articles. The minimum admissible temperature differential is maintained throughout the entire period of heat treatment of an article in the furnaces.     

Evaluation of a new organic azide: Hexakis(azidomethyl)benzene (HAB)

HAB is a thermally- and hydrolytically-stable solid, easily prepared from available raw materials. It is not highly sensitive to shock, friction, or electrostatic charge, but is sensitive to some types of impact, although not to others. It shows preliminary promise for possible use as a substitute for normal lead styphnate in less-sensitive bridgewire detonators, and as a substitute for tetracene in percussion detonators, e.g. the M-42 primer. Easy ignition, and a high burning rate without detonation, suggest application as an igniter. HAB is not sufficiently powerful to dent an aluminum witness block; therefore, it would not be suitable as a replacement for lead azide as an intermediate detonator charge.     

COMMERCIAL FIRING SURVEY OF CAR-TUNNEL KILNS*

Firing data were received from forty-eight manufacturers of many types of ceramic products. The products were divided into six classes, and minimum, maximum, and average values are presented in chart form on the firing cycle, loading, heat consumption, and firing costs. Fuel costs are analyzed, and data are given for two small, electric, twin-tunnel kilns.     

家用电器用绝缘搪瓷釉研究

家用电器用绝缘搪瓷釉研究蒋伟忠（轻工业部玻璃搪瓷工业科学研究所２０００５２）ＡｎＩｎｖｅｓｔｉｇａｔｉｏｎｏｎＩｎｓｕｌａｔｉｏｎＥｎａｍｅｌｆｏｒＥｌｅｃｔｒｉｃＡｐｐｌｉａｎｃｅ￥ＪｉａｎｇＷｅｉｚｈｏｎｇ（ＴｈｅＧｌａｓｓａｎｄＥｎａｍｅｌＲｅ...     

Technical investigation of the explosion on 22 March 1989 at Peterborough,England

The paper presents the results of a detailed technical investigations of the cause of the fire and subsequent explosion at Peterborough on 22 March 1989 involving a vehicle containing a mixed load of explosives and detonators. Tests were done to examine the sensitivenes and thermal stability of items of the load, and the behaviour of packaged explosives using drop, vibration and fire tests. Communication testing was undertaken with boxes of detonators, and ignition tests with boxes of fuseheads provided information relating to the characteristics of the fireballs generated. From analysis of the scientific data obtained, we conclude that the initial fire resulted from ignition of fusehead combs which were being transported in unauthorized and unsafe packaging, and we suggest a mechanism for detonatino involving the functioning of strewn detonators on fire-damaged boxes of explosives.