Research Of Twin Screw Extrusion Process Of Single-base Propellant Simulants

Screw extrusion technology has a significant place in the polymer processing process. Screw extrusion technology is widely used in many fields, such as rubber, plastics, food processing and explosives manufacturing. In recent years, a twin-screw extruder used in the field of viscous elastic material is one of one of the focus areas of polymer.The main research of this paper is a twin-screw extrusion technology in processing technology based single base propellant. Taking into account the safety and rationality of the experiment, firstly to look for substitute materials whose viscosity and molecular weight similar to the singlebase propellant and do extrusion experiments. The main components of single base propellant is nitrocellulose(NC), and substitute material were selectedin cellulose derivatives. Considering the molecular weight and its distribution and viscosity of NC, cellulose acetate(CA), hydroxypropyl methyl cellulose(HPMC), hydroxyethyl cellulose were choosed as substitute materials. Screw configuration was designed and extrusion process was optimized by HPMC. Secondly mixing tests were did and physical parameters of mixed materials of HPMC was characterized to determinethe constitutive equations, and researched the optimal ratio of mixed materials of HPMC and temperature. Thirdly, using a one-dimensional numerical simulation calculation software Ludovic to design screw configuration and analyzed different screw elements impacting on HPMC. Reasonable screw configurations were designed. The influences of different screw configurations and process parameters(feed rate, screw speed, barrel temperature) on HPMC in extrusion process were studied; Analyzing the temperature distribution, pressure distribution, mean residence time, mixing ratio and dissipated energy index, and explored the safety and efficiency of single base propellant extrusion process, the practical model of twin screw extrusion processof single base propellant was established.The function and role of different screw elements were studyed, combining with the existing screw configuration, designed a 9 groups reasonable screw configuration. By analyzing the screw configuration influenced on temperature distribution, pressure distribution, mean residence time, viscosity and mixing ratio of HPMC to choose the best screw configuration H5Y4.Twin-screw extrusion process was optimized, feed rate or screw speed had a linear relationship with temperature peak or average residence time. Under a certain screw speed, specific mechanical energy(SME) and temperature peak or torque was a linear correlation.