Study On The Mixing Performance Of High Chaotic-rotor Of Two-rotor Continuous Mixer

As an efficient continuous mixing device, two-rotor continuous mixer has been widely used in the production of high-loaded polymer composites. Aiming to resolve the problems of the classic rotors, a new chaotic-rotor with disconnected screws was designed based on the chaotic mixing theory. Three-dimensional non-Newtonian isothermal flow field simulation was carried out by means of POLYFLOW software to characterize the melt flow field in two-rotor continuous mixer corresponding to classical and chaotic rotors, respectively. Statistical analysis was performed to analyze the mixing process of polymer melts through particle tracking analysis (PTA) method. The influence of chaotic rotors’ structure, rotation speed and feed speed on mixing characteristic was also discussed. Moreover, the proposed two kinds of rotors were applied to compound calcium carbonate (CaCO3) and linear low density polyethylene (LLDPE). The average radius and radius distribution of calcium carbonate particles in the compounds were characterized, as well as the mechanical property. The conclusions are made as following:(1)The chaotic rotors have a better distributive mixing capability in comparison to the classic rotors, while the dispersive mixing capability is in equivalent level, which leads to a narrow particle size distribution of disperse phase in the compounds;(2)The screw flight misalignment angle directly affects the dispersive and distributive mixing capability of the rotors. When the misalignment angle is at 90°, the dispersive mixing capability of chaotic rotors and classic rotors is equal, while the distributive mixing capability achieves the highest level when the misalignment angel is at 60°;(3)Both of dispersive and distributive mixing capability would be promoted when the rotation speed is increased, which significantly improved the mechanical properties of blends. Besides, appropriate feed speed is also a key factor to achieve a better mixing performance;(4)The calcium carbonate/linear low density polyethylene compound, which is manufactured by the chaotic rotors, has better mechanical properties than that manufactured by classic rotors, including the breaking strength and elongation at break.