The Energetic Materials Extrusion Process represents one of the core technologies for forming and processing energetic materials including explosives, propellants (e.g., solid rocket propellants), and pyrotechnics. In this process, plastic or visco-flow energetic feedstock is mechanically extruded through a die with a specific profile, and continuously or semi-continuously shaped into products with defined geometric cross-sections, such as propellant grains, propellant strips, tubular grains, etc.
Features: It enables continuous production and possesses excellent mixing and self-cleaning performance. Currently, it serves as the mainstream equipment for the continuous manufacturing of polymer-based energetic materials.
Applications: Continuous nitration extrusion, continuous fabrication of composite modified double-base (CMDB) propellants, high solid loading propellants, and plastic-bonded explosives (PBX).
Extrusion processing of energetic materials generally consists of the following key steps:
Batching and Premixing: Energetic powders (such as RDX, HMX, CL-20, etc.), polymeric binders, plasticizers and functional additives are homogeneously blended to form a plastic paste-like feedstock.
Feeding and Conveying: Materials enter the extruder feed throat and flow toward the head under the propulsion of screws or rams.
Plasticization and Kneading: Inside the barrel, shear, compaction and temperature-controlled heating enable sufficient wetting and homogenization between polymeric binders and energetic particles, generating a continuous phase with favorable rheological properties.
Extrusion Forming at Die Head: Pressure builds up in the head, forcing the material through a profiled die orifice. The extrudate exits with the desired cross-section (single-perforation, multi-perforation, star-shaped, etc.).
Cooling/Curing and Cutting: The extruded propellant strands are shaped via air cooling, water cooling or thermal curing, and finally cut to the designed length.
Lemix tech has 11mm / 16mm twin screw extruder for testing& R&D
Lemix tech ‘s twin screw extruders offer a modular solution for application testing and process development from laboratory to pilot - scale.
All extruder sizes can be equipped with a modular upstream and downstream.
The screw combination are modular,the screw combination can be adjusted according to the formulation.
Clamshell barrel design helps makes process switching more flexible.
