Study on the mechanical and thermal parameters of PBX during the vertical extrusion charging process

To tackle challenges of man-machine contact, manual operation, and low degree of mechanical automation in the charging process of traditional polymer bonded explosive (PBX), we adopted a vertical extrusion charging process to realize continuous extrusion charging of the slurry into missiles. In this work, the screw structures were optimized via simulation software after slurry physical property analysis, as well as the influence of the parameters including speed and temperature on the process was further explored. The results indicated that, compared with the pineapple head structure featuring a high shear function, the conventional three-piece screw structure maintains the moderate fluctuation in viscous heating of the slurry, which is suitable for stable and safe delivery of high-sensitivity slurries. Meanwhile, an appropriate outlet size phi and barrel cone angle theta contributes to pressure distribution manipulation in the flow path, and a relatively high output was obtained at 30 mm and 1 degrees, respectively. Additionally, the adjustment of process parameters such as speed and temperature is conducive to reducing occurrence probability of local hot spots and restraining deformation of screw blade structures, the balance between output and process hazard was achieved.