Micro Injection Molding

Acknowledgments

Preface

About the Author

Contents

PART 1

1 Micro Injection Molding Machines Technology

1.1 Introduction

1.2 Patent Analysis

1.3 Architectures and Solutions for Micro Injection Molding Machines

1.3.1 Introduction to Functional-Based Modelling

1.3.2 Method

1.3.3 Functional Analysis

1.4 Appendix

References

2 Micro Molding Process Monitoring and Control

2.1 The Need for Process Monitoring in Micro Molding

2.2 Micro Molding Sensor Technologies

2.2.1 Volumetric Flow Rate

2.2.2 Temperature Sensors

2.2.3 Pressure Sensors

2.2.4 Ultrasonic Sensors

2.3 Visualization Systems

2.3.1 Tool Design for Visualization

2.3.2 High-Speed Imaging

2.3.3 Thermal Imaging Methods

2.4 Data Acquisition and Archiving Systems

2.4.1 Data Acquisition Hardware

2.4.2 Synchronization of DAQ Systems

2.4.3 Communication and Storage Strategies

2.5 Applications for Process Monitoring Systems

2.5.1 Qualification of Machine Performance

2.5.2 Material Quality Assessment

2.5.3 Process Window Evaluation

2.5.4 Simulation Boundary Conditions and Validation of Results

2.5.5 Sensor Development and Validation

2.5.6 Intelligent Process Control

References

3 Polymer Materials Structure and Properties in Micro Injection Molding Parts

3.1 Introduction

3.2 Specific Properties of Polymers for Micro Injection Molding Applications

3.3 Materials Scaling Effects in Micro Injection Molding

3.3.1 Rheology in the Micro and Nano Dimensional Ranges, at Low, High, and Ultra-High Shear Rates

3.3.2 Polymer pvT Properties at the Micro Scale

3.3.3 Thermal Properties of Polymers at the Micro Scale

3.3.4 Mechanical Properties of Micro Molded Components (Micro Tensile Test and Nano Indentation)

3.4 Molecular Orientation and Crystallinity in Micro Molded Parts

3.4.1 Amorphous Polymers

3.4.2 Semi-Crystalline Polymers

3.5 Micro/Nano Composites in Micro Injection Molding

References

4 Surface Replication in Micro Injection Molding

4.1 Replication of Micro and Nano Structures

4.2 Engineering of Micro- and Nanostructured Surfaces

4.2.1 Lithographic Techniques

4.2.2 Non-Lithographic Electrochemical-Based Techniques

4.3 Replication Assessment of Polymer Surfaces at the Sub-Micrometer Scale

4.3.1 Dimensional Evaluation of Replication Fidelity

4.3.2 Applications of Profile Measurements

4.3.3 Applications of Amplitude and Slope Replication of Polymer Surfaces

4.3.4 Applications of Areal Parameters

4.3.5 Application of Angular Intensity Distribution Measurements

4.4 Influence of Tooling and Process Parameters on Replication of Microstructures

4.4.1 Replication and Optimization of Deterministic Structures

4.4.2 Replication Quality of Large Area Nano-Structured Surfaces

4.4.3 Influence of Process Parameters on Surface Replication

References

PART 2

5 Micro Machining Technologies for Micro Injection Mold Making

5.1 Introduction

5.2 Process Chains for Micro Mold Making

5.3 Micro Mechanical Material Removal

5.3.1 Size Effects

5.3.2 Cutting Forces and Tool Deflection

5.3.3 Machine Tools

5.4 Micro Milling

5.4.1 Cutting Tools

5.5 Micro Turning

5.6 Micro Drilling

5.7 Thermal Material Removal Processes

5.8 Micro Electrical Discharge Machining

5.8.1 Micro EDM Sinking

5.8.2 Micro Wire EDM

5.8.3 Micro EDM Drilling

5.8.4 Wire Electrical Discharge Grinding

5.8.5 Micro EDM Milling

5.9 Application Examples of Machining Technologies for Micro Mold Making

5.9.1 Micro Mold Produced by Direct Tooling

5.9.2 Micro Mold Produced by Indirect Tooling

References

6 Ultra-Precision Machining Technologies for Micro Injection Mold Making

6.1 General Aspects of Ultra-Precision Machining

6.2 Diamond Machining

6.2.1 Diamond Turning

6.2.2 Diamond Milling

6.2.3 Shaping

6.3 Abrasive Machining

6.3.1 Process Chains

6.3.2 Ultra-Precision Grinding

6.3.3 Polishing

6.4 Applications of Ultra-Precision Machining

6.4.1 Fresnel Lens

6.4.2 Micro Beam Splitter

6.4.3 Diffractive Optical Elements

6.4.4 Retroreflectors

References

7 Surface Treatment of Mold Tools in Micro Injection Molding

7.1 Introduction

7.2 Investigation of DLC Surface Treatment Effects in Micro Injection Molding

7.2.1 Surface Treatment for Improved Demolding

7.2.2 An Experimental Case Study for Improving Part Demolding Using Surface Treatment

7.2.3 Validation, Verification, and Results

7.3 Temperature Effects on DLC-Coated Micro Molds

7.3.1 DLC Coatings Used on Micro Molds

7.3.2 An Experimental Case Study for Identifying the Temperature Effects on DLC-Coated Micro Molds

7.3.3 Validation, Verification, and Results

7.3.3.1 Linear and Superficial Thermal Expansion During Processing

7.3.3.2 Finite Element Analysis Results

7.3.4 Main Findings

7.4 A Novel Surface Treatment Texturing of Micro Injection Molding Tools

7.4.1 Mold Tool Texturing and Demolding Force

7.4.2 An Experimental Case Study for Tool Texturing

7.4.3 Validation, Verification, and Results

7.4.3.1 Nano-Structured Surfaces Replication and Demolding Forces

7.4.3.2 Main Findings

7.5 Conclusions

References

PART 3

8 Vacuum-Assisted Micro Injection Molding

8.1 Introduction

8.1.1 Air Evacuation in Injection Molding

8.1.2 Vacuum-Assisted Micro Injection Molding

8.1.3 Cavity Air Flow in Micro Injection Molding

8.2 Advantages and Limitations

8.3 Equipment and Design Solutions

8.3.1 Active Venting

8.3.2 Mold Design for Vacuum-Assisted Micro Injection Molding

8.3.3 Cavity Sealing

8.3.4 Vacuum Control

8.4 Effects on Replication

8.4.1 Height of Replicated Features

8.4.2 Feature Definition

8.4.3 Part Morphology

8.5 Venting Optimization

8.5.1 Effect of Micro Injection Molding Process Parameters

8.5.2 Effect of Polymer Selection

8.6 Concluding Remarks

References

9 Modeling and Simulation of Micro Injection Molding

9.1 Introduction

9.1.1 The Micro Injection Molding Process

9.1.2 Why Simulate the Injection Molding Process?

9.2 Mathematical Background

9.2.1 Viscosity of Plastics

9.2.2 Thermodynamics

9.2.3 Flow of Plastics

9.3 State-Of-The-Art and Challenges of Micro Injection Molding Simulations

9.4 Best Practice Strategies for Micro Molded Component Simulations

9.4.1 Modeling

9.4.2 Meshing

9.4.3 Material Data

9.4.4 Validation and Verification

9.5 Examples of Simulation-Aided Design and Simulated Phenomena

9.5.1 Gate Design Optimization

9.5.2 Hesitation Effect

9.6 Conclusions

References

10 Metrological Quality Assurance in Micro Injection Molding

10.1 Introduction

10.2 Quality of the Measurement Process: Calibration and Traceability

10.2.1 Accuracy and Precision

10.2.1.1 Repeatability and Reproducibility

10.3 Metrology for Micro Injection Molding

10.3.1 Dimensional Metrology

10.3.2 Surface Metrology

10.3.2.1 Areal Topography Measurements

10.4 Instrumentation for Micro Injection Molded Parts and Micro Injection Molding Tools

10.4.1 Optical Instruments

10.5 Uncertainty of Dimensional and Surface Topography Measurements of Micro Molded Parts and Micr

10.5.1 Assessment of the Uncertainty for Micro Injection Molding Applications

References

11 Additive Manufacturing for Micro Tooling and Micro Part Rapid Prototyping

11.1 Additive Manufacturing Process Technologies and Materials

11.1.1 Additive Manufacturing Methods for Polymer Materials

11.1.2 Additive Manufacturing Methods for Metal Materials

11.2 Additive Manufacturing Technologies for Micro Tooling

11.2.1 AM Technologies for Micro Injection Molding Hard Tooling Applications

11.2.2 AM Technologies for Micro Injection Molding Soft Tooling Applications

11.2.3 Indirect Methods for Micro Tooling Production

11.3 Additive Manufacturing for the Direct Manufacturing of Micro Products

References

PART 4

12 Micro Powder Injection Molding

12.1 Introduction

12.2 Process Description

12.2.1 Feedstocks for Powder Injection Molding

12.2.1.1 Binder

12.2.1.2 Powder Particle Properties

12.2.1.3 Feedstock Preparation and Rheological Properties

12.2.2 Debinding

12.2.3 Sintering

12.3 Powder Injection Molding of Micro Components (MicroPIM)

12.3.1 Dissimilarities between Powder and Plastics Injection Molding

12.3.2 Dissimilarities between Macro- and MicroPIM

12.4 2C Powder Injection Molding

12.5 Simulation of MicroPIM

12.5.1 MicroPIM Simulation by Use of Commercial Programs

12.5.2 MicroPIM Simulation Using Modified or Newly Developed Software Programs

12.6 Summary and Outlook

References

13 Multimaterial Micro Injection Molding

13.1 Introduction

13.2 Multimaterial Molding and Multimaterial Micro Molding

13.2.1 Introduction and Applications

13.2.2 Application Areas

13.2.3 Advantages and Disadvantages

13.2.4 Variants of Multimaterial Molding

13.3 Two-Component Micro Molding

13.3.1 Polymer–Polymer Bonding

13.3.1.1 Hypotheses on Adhesion of 2K Molded Polymers

13.3.1.2 Experimental Investigations and Results

13.3.1.3 Other Factors Affecting Bonding between Polymers

13.3.1.4 Effects of Surface Roughness on the Bonding of Two Polymers

13.3.1.5 Effects of Environmental Factors

13.3.2 Polymer–Polymer Interface

13.3.2.1 Challenges for 2K Injection Molding: Bonding and Interface Dilemma

13.3.2.2 Special Considerations for the Polymer–Polymer Interface of Micro Parts

13.4 Adhesion Modification for Multicomponent Molding

13.5 Other Quality Issues for Multicomponent Micro Molding

13.6 Conclusion

References

Index