Since 1976, Clextral has been developing twin-screw extrusion systems specifically designed to mix viscous energetic materials for a range of civil and military applications. For example, the mix-extrusion process is used in pyrotechnics (continuous mix and shaping through extrusion), an area where Clextral has several major industrial references throughout the world.
There are several advantages in using twin-screw extrusion to make energetic materials, compared to traditional batch systems using internal mixers:
- Cost-effective investments with competitive costs compared to traditional batch systems and reduction of direct labor costs
- Extension of eligible raw materials
- Consistent quality through continuous processing and easy repeatability (archives and parameter records)
- Compliance to highest quality and security standards, because of product confinement
Twin-screw extrusion ensures a maximum level of security in the processing of energetic materials by radically reducing the risks of explosion and spontaneous combustion. This is due to the efficient mixing capacities of the extruder and the small amount of materials at any given point in continuous processing in the barrel-screw section and its very short residency time (in general about one minute).
Security during production is also ensured by precise instrumentation that controls the temperatures in the barrel in each zone with the use of a sensor tracking the material and pressure. Specific automation and ultra-precise state-of-the-art manufacturing parts ensure added security.
Finally, degassing of the viscous material is done through several openings all along the barrel with atmospheric vents or vacuum wells linked to one or several vacuum pumps.