Precision Injection Molding

Transcription

1 Precision Injection Molding Jehuda Greener, Reinhold Wimberger-Friedl Process, Materials and Applications ISBN Weitere Informationen oder Bestellungen unter sowie im Buchhandel

2 Contents List of Contributors... Dedication... Preface... V VII IX 1 Precision Injection Molding: Overview and Scaling Considerations... 1 J. Greener, R. Wimberger-Friedl 1.1 Introduction The M-Chain of Precision Molding Dimensional Integrity Pressure History Cooling Stresses Shrinkage Warpage Dimensional Stability Simulation Summary Instabilities in Dimensions and Shape L. C. E. Struik 2.1 Introduction Creep-Recovery; Isothermal Creep-Recovery; Nonisothermal Nonisothermal Creep Recovery Accompanied by Physical Aging Complicated Loading Patterns During Shaping Predicting Long-Term Dimensional Instability from Short-Time Tests Discussion Applicability of the Linear Viscoelastic Theory Factors Determining Instabilities Related Phenomena Volume Relaxation and Cooling Stresses Dimensional Accuracy in Injection Molding: State of the Art and Open Challenges R. Pantani, G. Titomanlio 3.1 Introduction Generalities on Shrinkage and Thermal Stresses Parameters Affecting Shrinkage Some Aspects of Injection Molding of Interest for Shrinkage Predictions... 31

3 XII Contents 3.5 State of the Art of Shrinkage Modelling PVT Approach Statistical Approach Thermomechanical Approach Elastic Modeling of Shrinkage The Physical Basis of the Model Definitions and Main Equations Derivation of Shrinkage Equations A Viscoelastic Approach to Shrinkage A Reliable Solidification Criterion and Relaxation in the Solid State Relevance of Solidification Criterion on Stresses and Shrinkage Shrinkage and Thermal Stresses of Semicrystalline Polymers Dimensional Instability After Molding Birefringence Modeling in Optical Discs T. H. Kwon, Y. B. Lee 4.1 Introduction ThermalStressandBirefringence Stress-Optical Behavior Stress-Optical Law and Photoelasticity Linear Viscoelasticity and Photoviscoelasticity Time-Temperature Superposition Photoviscoelasticity Experiment Volume Relaxation Phenomena with Free Volume Theory Material Data Birefringence in Injection Molded Center-Gated Disks Physical Model Residual Stresses and Birefringence Numerical Modeling Numerical Simulation Results and Discussion Concluding Remarks Shrinkage of Injection Molded Material P. K. Kennedy, R. Zheng 5.1 Introduction Filling and Packing Analysis Material Properties Geometric Considerations Simplification by Mathematical Analysis Solution of the Governing Equations Cooling Analysis Shrinkage and Warpage Prediction Residual Strain Methods Residual Stress Models

4 Contents XIII 5.5 The Material Data Problem HybridModel The Contracted Notation Prediction of the b i Using the Model Results for Unfilled Polypropylene Results on Other Materials ABS PC PC+ABS Blend PBT Filled Materials Glass Reinforced PA Talc Filled PBT Conclusion Towards the Prediction of Structure Development in Injection Molded Semicrystalline Polymers G. Eder, H. Janeschitz-Kriegl, E. Ratajski 6.1 Introduction Phenomenology of Crystallization Patterns Suitable Parameters for a Description of Underlying Processes Fundamental Considerations for Quiescent Melts Fundamentals of Flow-Induced Crystallization Outlook Deformation of Polycarbonate Optical Discs by Water Sorption and Aging L. van der Tempel 7.1 Introduction Water Sorption Physical Aging Disc Warpage by Water Sorption and Volume Relaxation Experimental Introduction Model Water Sorption and Swell in Polycarbonate Model Measurement Methods for Swell and Diffusivity Swell Water Diffusion Volume Shrinkage of Polycarbonate Substrates During Hot Storage Measurements Model Conclusions

5 XIV Contents 8 Injection Molding for Microfluidics Applications L. J. Lee, L. Yu, K. W. Koelling, M. J. Madou 8.1 Introduction Microfluidics Basic Concepts Micro- and Nanofluidic Functions Mold (Master) Making LIGA UV-LIGA Comparison of Various Mold-Making Methods Microfeature Injection Molding Techniques and Applications Molding of CDs and DVDs Thermoplastic Microfeature Injection Molding Reaction Injection Molding (RIM) Demolding Injection Molding with Nanostructures Experimental Analysis of Microfeature Injection Molding Experiments of Microfeature Injection Molding Unidirectional Mold Filling with Microfeatures Theoretical Analysis of Microfeature Injection Molding An Analytic Model for Pressure Estimation Simulation with Commercial Codes Hybrid Numerical Simulation Thermal Boundary Conditions Test of the Hybrid Numerical Scheme and Thermal Boundary Conditions Other Microfluidic Related Issues FutureDirections Introduction to Micromolding B. R. Whiteside, M. T. Martyn, P. D. Coates 9.1 Introduction Technology Tooling Materials Process Monitoring and Assessment Product Property Measurement Summary Precision Process Control of Precision Injection Molding D. Kazmer 10.1 Introduction Fundamentals

6 Contents XV Injection Molding Fundamentals Process Control Fundamentals Robust Design Fundamentals Process Control Technologies Machine Control State Variable Control Set-Point Control Precision Process Control Development Methodology Example #1: Process Window Determination for DVD Manufacturing Example #2: Dynamic Feed Conclusions Machine Hardware for Precision Injection Molding J. Border 11.1 Introduction Precision Injection Molding Machines Hydraulic Control vs. Electric Control ScrewShutoff Melting Screws Machine Layout Special Material Processing Automated Part Handling Machine Sizes Machine General Molds Mold Material Selection Machining Precision Plate Interlocks Across the Parting Line Mold Temperature Control MoldTypes Summary Index