Influence Of Screw Configurations Of Tse On The Properties And Morphology Of PP/PA6 Blends

The main factors of influencing PP/PA6 blends properties include the formula,compatilizer,operating condition,mixing equipments and so on.For the mixing equipments,the screw configurations is the key factor in influencing the PP/PA6 blends properties.In this paper,the flow field of different screw configurations for three-dimensional isothermal Non-Newtonian model in intermeshing co-rotating twin screw extruder were simulated by using the professional package of Computational Fluid Dynamics,POLYFLOW.The screw configurations included KB+S(kneading blocks and S element) and S+KB(S element and kneading blocks).Velocity field,pressure field,shear-stress field, backflow rate and residence time distribution were obtained.The mixing ability of different screw configurations was compared.The KB+S showed excellent performance on distributive mixing ability,because the screw configuration had greater backflow and wider RTD.The analysis also indicated that it had greater shear stress and excellent dispersive mixing ability, this result was validated by experiments. In this paper,the effect of the formula(PP/PA6/PP-g-MAH) on mechanical property of blends was studied through orthogonal experimental design(L₁₆(4)³).The results showed that PP-g-MAH had the biggest influence on comprehensive mechanical property of PP/PA6 blends,then the PA6.The influence of operating temperature and screw speed on mechanical property of blends was studied.The results showed that the tensile-strength and bending strength of blends reduced as the operating temperature increased and enhanced as the screw speed rised.The impact strength of blends raised with the operating temperature increased and slightly fluctuated with the screw speed rised.The influence of six different screw configurations on the phase morphology and performance of PP/PA6 blends was studied,by setting kneading blocks(KB) and S element(S) in the melting section and setting TME elements,FTX elements as well as NI-MPE elements in the melt conveying section in the co-rotating twin screw extruder.The results showed that KB (setting in the melting section)+FTX(setting in the melt conveying section) could obtain a good shock resistance and processing properties of polymer alloy material.