Simulation Study on Plasticizing Process of Modified Double‐Base Propellant by Groove Calendering

ABSTRACT The flammable and explosive properties of modified double‐base propellants have caused frequent safety incidents during the calendering and plasticizing processes. This article uses the finite element analysis software Polyflow to study the flow characteristics and mixing mechanisms of materials under varying speed ratios, roller speeds, and roller spacing. Additionally, it aims to optimize process parameters and enhance the safety of the calendering process. The distribution of parameters such as speed, mixing index, viscosity, and shear stress in the calendering process was analyzed. The following results were obtained by analyzing the distribution of material speed, mixing index, viscosity, shear stress, and other parameters during the calendering process: Material accumulated at the outlet forms a reflux motion due to the roller's rotation, and variations in reflux motion under different process parameters affect the mixing uniformity and safety of the calendering process. When the rotational speed ratio is 25:20, the risk of explosion during the calendering process is reduced. Increasing the rotational rate increases the backflow speed, and increasing the roller spacing improves the backflow movement and expands the backflow area. In the entire material flow region, the average flow speed in the middle section is the lowest, whereas the viscosity and shear stress are the highest. When the rotational speeds of the work roller and the idling roller are 25:20 rpm, and the roller spacing is 1.2 mm, the calendering process achieves the highest safety and the best product mixing uniformity.