The flow process of unplasticized polyvinyl chloride （U PVC） through the mixing zone of intermeshing counter rotating and co rotating twin screw extruders （TSEs） were numerically simula ted by the finite element m...The flow process of unplasticized polyvinyl chloride （U PVC） through the mixing zone of intermeshing counter rotating and co rotating twin screw extruders （TSEs） were numerically simula ted by the finite element method. Three dimensional isothermal flow field of U-PVC in two kinds of TSE was calculated. The mixing performance of the screw elements of the extruders was statistically analyzed by particle tracking method. The dispersive mixing performance was characterized by the mixing index, the logarithm of stretching, and the segregation scale. The distributive mixing per forulance was characterized by the resident time distribution. The results indicate that the counter rotating TSE can build higher pressure and generate higher axial velocity and shear rate, whereas the co rotating TSE has better performance in dispersive and distributive mixing.展开更多
Roller leveling process of longitudinal profile （LP） plate is hardly studied because plate thickness changes. Deformation characteristics and residual curvature during LP plate leveling process were investigated bas...Roller leveling process of longitudinal profile （LP） plate is hardly studied because plate thickness changes. Deformation characteristics and residual curvature during LP plate leveling process were investigated based on curva ture integral by elastic plastic differences. It was found that entry intermesh section is reduced with increasing thick- ness and entry intermesh should be from 0.7 to 1.1 mm for LP plate with 42/54 mm in thickness. In order to get satisfactory flatness along longitudinal direction, small entry intermesh should be selected and exit intermesh should be 0 ram. In addition, thickness section for I.P plate which can be leveled by 11 roller leveler is from 24 to 60 mm. Finally, there is an intermesh schedule that could level LP plate with initial curvature less than elastic limit curvature.展开更多
基金Supported by the Industrial Foundation(20091041038)
文摘The flow process of unplasticized polyvinyl chloride （U PVC） through the mixing zone of intermeshing counter rotating and co rotating twin screw extruders （TSEs） were numerically simula ted by the finite element method. Three dimensional isothermal flow field of U-PVC in two kinds of TSE was calculated. The mixing performance of the screw elements of the extruders was statistically analyzed by particle tracking method. The dispersive mixing performance was characterized by the mixing index, the logarithm of stretching, and the segregation scale. The distributive mixing per forulance was characterized by the resident time distribution. The results indicate that the counter rotating TSE can build higher pressure and generate higher axial velocity and shear rate, whereas the co rotating TSE has better performance in dispersive and distributive mixing.
基金Item Sponsored by National Natural Science Foundation of China(50604006,50974039)
文摘Roller leveling process of longitudinal profile （LP） plate is hardly studied because plate thickness changes. Deformation characteristics and residual curvature during LP plate leveling process were investigated based on curva ture integral by elastic plastic differences. It was found that entry intermesh section is reduced with increasing thick- ness and entry intermesh should be from 0.7 to 1.1 mm for LP plate with 42/54 mm in thickness. In order to get satisfactory flatness along longitudinal direction, small entry intermesh should be selected and exit intermesh should be 0 ram. In addition, thickness section for I.P plate which can be leveled by 11 roller leveler is from 24 to 60 mm. Finally, there is an intermesh schedule that could level LP plate with initial curvature less than elastic limit curvature.
