Transient Polymer Flow Rate in Injection Mold Filling
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Abstract
An analytical and experimental study of the transient flow behavior of polymer melt in injection molding is presented. The polymer volume flow rate into a rectangular mold cavity during the filling stage was determined using the Reynold's transport theory. The analysis, which neglects melt elasticity, shows that the flow rate is transient during the initial filling of the cavity. Moreover, the cavity flow rate was found to depend on material compressibility and expansivity, total volume upstream of the gate as well as time rate of change of melt pressure and temperature. Experimental results obtained through direct flow visualization are in good agreement with the theory. The effect of gate size on the cavity flow rate was also examined. A small gate gives rise to a greater degree of melt compressibility in the runner system. The prediction of actual flow rates into the cavity not only enhances determination of the interrelationship of flow rate, morphology, and properties in injection molding but also aids in the avoidance of molding defects. The results of this study can be used to improve the accuracy of CAE analysis.
© 2000, Carl Hanser Verlag, Munich
Articles in the same Issue
- Editorial
- Third of a Series: Pioneering Polymer Industry Developments — The First Successful Mathematical-Computer Modeling of A Complex Industrial Process: Toyobo and Melt Spinning
- Screw Extrusion / Mixing
- Polymer Flow Velocity in the Helical Channel in Dependence of a Coordinate System
- Non-Isothermal Transient Startup of A Starved Flow Modular Co-Rotating Twin Screw Extruder
- Numerical Simulations and Experiments in a Double-Couette Flow Geometry
- Dynamic Analysis of Melting in Injection Extruder
- Extrusion Die
- Production of Pipe with Uniform Wall Thickness: How to Compensate for Gravity Sag
- Fiber and Film
- Assessment of LDPE Melt Strength by Use of Rheotens Mastercurves
- Molding
- Analysis of Flow and Heat Transfer in Liquid Composite Molding
- Solidification Criterion on Shrinkage Predictions for Semi-crystalline Injection Moulded Samples
- Polymer Melt Rheology at High Shear Rates
- Factors Affecting the Stability of Gas Penetration in Gas Assist Injection Molded Bifurcation Parts
- Transient Polymer Flow Rate in Injection Mold Filling
- Flow Analysis of Injection-Press Molding Process
- Properties of Injection Molded In Situ Composites Based on PPS and a Melt Processable Glass
- A New Approach in Offline-Optimization of the Injection Molding Process
Articles in the same Issue
- Editorial
- Third of a Series: Pioneering Polymer Industry Developments — The First Successful Mathematical-Computer Modeling of A Complex Industrial Process: Toyobo and Melt Spinning
- Screw Extrusion / Mixing
- Polymer Flow Velocity in the Helical Channel in Dependence of a Coordinate System
- Non-Isothermal Transient Startup of A Starved Flow Modular Co-Rotating Twin Screw Extruder
- Numerical Simulations and Experiments in a Double-Couette Flow Geometry
- Dynamic Analysis of Melting in Injection Extruder
- Extrusion Die
- Production of Pipe with Uniform Wall Thickness: How to Compensate for Gravity Sag
- Fiber and Film
- Assessment of LDPE Melt Strength by Use of Rheotens Mastercurves
- Molding
- Analysis of Flow and Heat Transfer in Liquid Composite Molding
- Solidification Criterion on Shrinkage Predictions for Semi-crystalline Injection Moulded Samples
- Polymer Melt Rheology at High Shear Rates
- Factors Affecting the Stability of Gas Penetration in Gas Assist Injection Molded Bifurcation Parts
- Transient Polymer Flow Rate in Injection Mold Filling
- Flow Analysis of Injection-Press Molding Process
- Properties of Injection Molded In Situ Composites Based on PPS and a Melt Processable Glass
- A New Approach in Offline-Optimization of the Injection Molding Process
