Based on mechanics to design hollow plastic parison shape,this paper adopted computer and programmable logic controllers(PLCs) to build a three level system,finish the CAD of parison,and control the blow molding seque...Based on mechanics to design hollow plastic parison shape,this paper adopted computer and programmable logic controllers(PLCs) to build a three level system,finish the CAD of parison,and control the blow molding sequentially.Parison thickness was controlled by an electro hydraulic proportional control system,which controls the gap between the parison and the nozzle during the extrusion process by regulating the position of the core bar.Both constant pressure and speed control systems were adopted to control the process of plastic storing and extrusion,and PLC,such as C200H and CQM1,fuzzy modules were adopted.The results show that the part quality of blow molding can be improved greatly.展开更多
Swell and sag drawdown significantly influence the high density polyethylene parison. Nu- merical simulations of the flow field of a HDPE melt were performed using the finite element method for the die of plastic pipe...Swell and sag drawdown significantly influence the high density polyethylene parison. Nu- merical simulations of the flow field of a HDPE melt were performed using the finite element method for the die of plastic pipe extrusion and parison formation. The constitutive equation of Carreau law was used to describe the polymer melt in the flow domain. The distributions of the velocity, shear rate, viscosity, pressure, thickness and radius are presented with Polyflow. The effect of flow rate and temperature on extrusion swell and parison sag was investigated. The results show that the thickness of the parison increases with increasing flow rate. The thickness and radius of the parison are more sensitive to changes in flow rates than to changes in temperatures.展开更多
The e?ect of material anisotropy on the bifurcation for void formation in anisotropic compressible hyperelastic materials is examined. Numerical solutions are obtained in an anisotropic sphere, whose material is tra...The e?ect of material anisotropy on the bifurcation for void formation in anisotropic compressible hyperelastic materials is examined. Numerical solutions are obtained in an anisotropic sphere, whose material is transversely isotropic in the radial direction. It is shown that the bifur- cation may occur either to the right or to the left, depending on the degree of material anisotropy. The deformation and stress contribution in the sphere before cavitation are di?erent from those after cavitation. The stability of solutions is discussed through a comparison of energy.展开更多
文摘Based on mechanics to design hollow plastic parison shape,this paper adopted computer and programmable logic controllers(PLCs) to build a three level system,finish the CAD of parison,and control the blow molding sequentially.Parison thickness was controlled by an electro hydraulic proportional control system,which controls the gap between the parison and the nozzle during the extrusion process by regulating the position of the core bar.Both constant pressure and speed control systems were adopted to control the process of plastic storing and extrusion,and PLC,such as C200H and CQM1,fuzzy modules were adopted.The results show that the part quality of blow molding can be improved greatly.
文摘Swell and sag drawdown significantly influence the high density polyethylene parison. Nu- merical simulations of the flow field of a HDPE melt were performed using the finite element method for the die of plastic pipe extrusion and parison formation. The constitutive equation of Carreau law was used to describe the polymer melt in the flow domain. The distributions of the velocity, shear rate, viscosity, pressure, thickness and radius are presented with Polyflow. The effect of flow rate and temperature on extrusion swell and parison sag was investigated. The results show that the thickness of the parison increases with increasing flow rate. The thickness and radius of the parison are more sensitive to changes in flow rates than to changes in temperatures.
基金Project supported by the National Natural Science Foundation of China (No.10272069) and the Shanghai Key SubjectProgram.
文摘The e?ect of material anisotropy on the bifurcation for void formation in anisotropic compressible hyperelastic materials is examined. Numerical solutions are obtained in an anisotropic sphere, whose material is transversely isotropic in the radial direction. It is shown that the bifur- cation may occur either to the right or to the left, depending on the degree of material anisotropy. The deformation and stress contribution in the sphere before cavitation are di?erent from those after cavitation. The stability of solutions is discussed through a comparison of energy.
