Design of Safe Ignition Compositions for Environmentally Benign Detonator Systems

The development of compact, reliable detonators without heavy-metal-based primary explosives remains a major challenge in energetic materials engineering. This work introduces a heavy-metal-free KClO 4 (KP)/Al ignition charge with a PVAc binder that enables reproducible deflagration-to-detonation transition (DDT) of PETN in steel initiation elements at ignition charge masses substantially lower than those reported for comparable non-primary explosive detonator concepts. Granulation of the KP/Al formulation with 1 wt.% PVAc markedly reduced sensitivity to friction, impact, and electrostatic discharge, while preserving sufficient ignition performance as verified by US Flash and HSL closed-vessel tests. Using water-tank experiments combined with high-speed imaging and pressure-based energy analysis, the ignition charge mass was identified as a critical control parameter governing DDT reliability in the PETN transition column. A narrow optimal window of 20–30 mg was found to ensure stable and repeatable DDT, whereas lower masses led to frequent misfires and higher masses induced premature casing deformation and gas leakage, limiting the effective pressurization of the transition column. Initiation elements incorporating 30 mg of the developed ignition charge reliably initiated a 600 mg PETN secondary charge and reached an initiation strength comparable to that of a standardized reference detonator. These results demonstrate a viable pathway toward compact, environmentally benign, and inherently safer detonator designs that eliminate primary explosives without compromising initiation performance.