Tosello Micro Injection Molding

1. Auflage 2018
ISBN: 978-1-56990-654-5
Verlag: Hanser Publications
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 408 Seiten

"Micro Injection Molding" meets the need for a dedicated book dealing exclusively with micro injection molding and overcoming the challenges of managing and processing polymer materials at ultra-small scales. Micro injection molding is the primary process for the mass production of polymer components with critical dimensions in the sub-millimeter range; however, it is not just a simple downscaling of conventional injection molding, and specific material-process-product interactions must be understood in order to achieve near zero-defect net-shape micro molded products.

Micro molding is typically associated with ultra-high accuracy and superior process capabilities. Micro molded products have dimensional tolerances down to the single-digit micrometer range and surface finish with roughness from the sub-micrometer down to a few nanometers range. Micro and nano-structured tool surfaces are reproduced with very high replication fidelity onto the polymer products. Micro injection molding is highly suitable for the manufacture of multifunctional micro components such as micro implants, microfluidic systems, polymer micro optical elements, and micro mechanical systems.

This book provides engineers, project managers, researchers, consultants, and other professionals involved in precision polymer processing and micro manufacturing with a comprehensive, up-to-date, and detailed treatment of the main topics related to micro molding, from material and process technology to tooling, to key-enabling technologies, and multimaterial process variations.

Contents:
• Part 1 – Polymer Materials and Process Micro Technology: micro injection molding machines technology; micro molding process monitoring and control; polymer materials structure and properties in micro injection molding parts; surface replication in micro injection molding
• Part 2 – Tooling Technologies for Micro Mold Making: micro machining technologies for micro injection mold making; ultra-precision machining technologies for micro injection mold making; surface treatment of mold tools in micro injection molding
• Part 3 – Micro Molding Key-Enabling Technologies: vacuum-assisted micro injection molding; modeling and simulation of micro injection molding; metrological quality assurance in micro injection molding; additive manufacturing for micro tooling and micro part rapid prototyping
• Part 4 – Multimaterial Micro Processing: micro powder injection molding; multimaterial micro injection molding

Autoren/Hrsg.

Tosello, Guido

Inhaltsverzeichnis

1;Acknowledgments;7
2;Preface;9
3;About the Author;13
4;Contents;15
5;PART 1;23
5.1;1 Micro Injection Molding Machines Technology;25
5.1.1;1.1 Introduction;25
5.1.2;1.2 Patent Analysis;25
5.1.3;1.3 Architectures and Solutions for Micro Injection Molding Machines;31
5.1.3.1;1.3.1 Introduction to Functional-Based Modelling;31
5.1.3.2;1.3.2 Method;34
5.1.3.3;1.3.3 Functional Analysis;35
5.1.4;1.4 Appendix;47
5.1.4.1;References;50
5.2;2 Micro Molding Process Monitoring and Control;53
5.2.1;2.1 The Need for Process Monitoring in Micro Molding;53
5.2.2;2.2 Micro Molding Sensor Technologies;54
5.2.2.1;2.2.1 Volumetric Flow Rate;54
5.2.2.2;2.2.2 Temperature Sensors;56
5.2.2.3;2.2.3 Pressure Sensors;57
5.2.2.4;2.2.4 Ultrasonic Sensors;59
5.2.3;2.3 Visualization Systems;60
5.2.3.1;2.3.1 Tool Design for Visualization;60
5.2.3.2;2.3.2 High-Speed Imaging;61
5.2.3.3;2.3.3 Thermal Imaging Methods;64
5.2.4;2.4 Data Acquisition and Archiving Systems;64
5.2.4.1;2.4.1 Data Acquisition Hardware;64
5.2.4.2;2.4.2 Synchronization of DAQ Systems;66
5.2.4.3;2.4.3 Communication and Storage Strategies;66
5.2.5;2.5 Applications for Process Monitoring Systems;67
5.2.5.1;2.5.1 Qualification of Machine Performance;67
5.2.5.2;2.5.2 Material Quality Assessment;69
5.2.5.3;2.5.3 Process Window Evaluation;70
5.2.5.4;2.5.4 Simulation Boundary Conditions and Validation of Results;72
5.2.5.5;2.5.5 Sensor Development and Validation;73
5.2.5.6;2.5.6 Intelligent Process Control;75
5.2.5.7;References;76
5.3;3 Polymer Materials Structure and Properties in Micro Injection Molding Parts;79
5.3.1;3.1 Introduction;79
5.3.2;3.2 Specific Properties of Polymers for Micro Injection Molding Applications;80
5.3.3;3.3 Materials Scaling Effects in Micro Injection Molding;81
5.3.3.1;3.3.1 Rheology in the Micro and Nano Dimensional Ranges, at Low, High, and Ultra-High Shear Rates;82
5.3.3.2;3.3.2 Polymer pvT Properties at the Micro Scale;85
5.3.3.3;3.3.3 Thermal Properties of Polymers at the Micro Scale;87
5.3.3.4;3.3.4 Mechanical Properties of Micro Molded Components (Micro Tensile Test and Nano Indentation);89
5.3.4;3.4 Molecular Orientation and Crystallinity in Micro Molded Parts;92
5.3.4.1;3.4.1 Amorphous Polymers;93
5.3.4.2;3.4.2 Semi-Crystalline Polymers;95
5.3.5;3.5 Micro/Nano Composites in Micro Injection Molding;98
5.3.5.1;References;101
5.4;4 Surface Replication in Micro Injection Molding;105
5.4.1;4.1 Replication of Micro and Nano Structures;105
5.4.2;4.2 Engineering of Micro- and Nanostructured Surfaces;108
5.4.2.1;4.2.1 Lithographic Techniques;109
5.4.2.2;4.2.2 Non-Lithographic Electrochemical-Based Techniques;110
5.4.3;4.3 Replication Assessment of Polymer Surfaces at the Sub-Micrometer Scale;113
5.4.3.1;4.3.1 Dimensional Evaluation of Replication Fidelity;114
5.4.3.2;4.3.2 Applications of Profile Measurements;115
5.4.3.3;4.3.3 Applications of Amplitude and Slope Replication of Polymer Surfaces;116
5.4.3.4;4.3.4 Applications of Areal Parameters;119
5.4.3.5;4.3.5 Application of Angular Intensity Distribution Measurements;121
5.4.4;4.4 Influence of Tooling and Process Parameters on Replication of Microstructures;123
5.4.4.1;4.4.1 Replication and Optimization of Deterministic Structures;123
5.4.4.2;4.4.2 Replication Quality of Large Area Nano-Structured Surfaces;126
5.4.4.3;4.4.3 Influence of Process Parameters on Surface Replication;128
5.4.4.4;References;131
6;PART 2;135
6.1;5 Micro Machining Technologies for Micro Injection Mold Making;137
6.1.1;5.1 Introduction;137
6.1.2;5.2 Process Chains for Micro Mold Making;139
6.1.3;5.3 Micro Mechanical Material Removal;143
6.1.3.1;5.3.1 Size Effects;144
6.1.3.2;5.3.2 Cutting Forces and Tool Deflection;146
6.1.3.3;5.3.3 Machine Tools;146
6.1.4;5.4 Micro Milling;147
6.1.4.1;5.4.1 Cutting Tools;147
6.1.5;5.5 Micro Turning;149
6.1.6;5.6 Micro Drilling;150
6.1.7;5.7 Thermal Material Removal Processes;150
6.1.8;5.8 Micro Electrical Discharge Machining;151
6.1.8.1;5.8.1 Micro EDM Sinking;154
6.1.8.2;5.8.2 Micro Wire EDM;154
6.1.8.3;5.8.3 Micro EDM Drilling;155
6.1.8.4;5.8.4 Wire Electrical Discharge Grinding;155
6.1.8.5;5.8.5 Micro EDM Milling;155
6.1.9;5.9 Application Examples of Machining Technologies for Micro Mold Making;157
6.1.9.1;5.9.1 Micro Mold Produced by Direct Tooling;157
6.1.9.2;5.9.2 Micro Mold Produced by Indirect Tooling;158
6.1.9.3;References;160
6.2;6 Ultra-Precision Machining Technologies for Micro Injection Mold Making;163
6.2.1;6.1 General Aspects of Ultra-Precision Machining;165
6.2.2;6.2 Diamond Machining;166
6.2.2.1;6.2.1 Diamond Turning;166
6.2.2.2;6.2.2 Diamond Milling;169
6.2.2.3;6.2.3 Shaping;172
6.2.3;6.3 Abrasive Machining;174
6.2.3.1;6.3.1 Process Chains;174
6.2.3.2;6.3.2 Ultra-Precision Grinding;175
6.2.3.3;6.3.3 Polishing;179
6.2.4;6.4 Applications of Ultra-Precision Machining;181
6.2.4.1;6.4.1 Fresnel Lens;182
6.2.4.2;6.4.2 Micro Beam Splitter;182
6.2.4.3;6.4.3 Diffractive Optical Elements;183
6.2.4.4;6.4.4 Retroreflectors;184
6.2.4.5;References;186
6.3;7 Surface Treatment of Mold Tools in Micro Injection Molding;191
6.3.1;7.1 Introduction;191
6.3.2;7.2 Investigation of DLC Surface Treatment Effects in Micro Injection Molding;192
6.3.2.1;7.2.1 Surface Treatment for Improved Demolding;192
6.3.2.2;7.2.2 An Experimental Case Study for Improving Part Demolding Using Surface Treatment;193
6.3.2.3;7.2.3 Validation, Verification, and Results;194
6.3.3;7.3 Temperature Effects on DLC-Coated Micro Molds;195
6.3.3.1;7.3.1 DLC Coatings Used on Micro Molds;195
6.3.3.2;7.3.2 An Experimental Case Study for Identifying the Temperature Effects on DLC-Coated Micro Molds;197
6.3.3.3;7.3.3 Validation, Verification, and Results;198
6.3.3.3.1;7.3.3.1 Linear and Superficial Thermal Expansion During Processing;198
6.3.3.3.2;7.3.3.2 Finite Element Analysis Results;199
6.3.3.4;7.3.4 Main Findings;202
6.3.4;7.4 A Novel Surface Treatment Texturing of Micro Injection Molding Tools;202
6.3.4.1;7.4.1 Mold Tool Texturing and Demolding Force;202
6.3.4.2;7.4.2 An Experimental Case Study for Tool Texturing;203
6.3.4.3;7.4.3 Validation, Verification, and Results;206
6.3.4.3.1;7.4.3.1 Nano-Structured Surfaces Replication and Demolding Forces;206
6.3.4.3.2;7.4.3.2 Main Findings;208
6.3.5;7.5 Conclusions;208
6.3.5.1;References;209
7;PART 3;213
7.1;8 Vacuum-Assisted Micro Injection Molding;215
7.1.1;8.1 Introduction;215
7.1.1.1;8.1.1 Air Evacuation in Injection Molding;215
7.1.1.2;8.1.2 Vacuum-Assisted Micro Injection Molding;216
7.1.1.3;8.1.3 Cavity Air Flow in Micro Injection Molding;217
7.1.2;8.2 Advantages and Limitations;217
7.1.3;8.3 Equipment and Design Solutions;219
7.1.3.1;8.3.1 Active Venting;219
7.1.3.2;8.3.2 Mold Design for Vacuum-Assisted Micro Injection Molding;220
7.1.3.3;8.3.3 Cavity Sealing;223
7.1.3.4;8.3.4 Vacuum Control;223
7.1.4;8.4 Effects on Replication;224
7.1.4.1;8.4.1 Height of Replicated Features;224
7.1.4.2;8.4.2 Feature Definition;225
7.1.4.3;8.4.3 Part Morphology;227
7.1.5;8.5 Venting Optimization;228
7.1.5.1;8.5.1 Effect of Micro Injection Molding Process Parameters;228
7.1.5.2;8.5.2 Effect of Polymer Selection;230
7.1.6;8.6 Concluding Remarks;232
7.1.6.1;References;232
7.2;9 Modeling and Simulation of Micro Injection Molding;235
7.2.1;9.1 Introduction;235
7.2.1.1;9.1.1 The Micro Injection Molding Process;235
7.2.1.2;9.1.2 Why Simulate the Injection Molding Process?;236
7.2.2;9.2 Mathematical Background;237
7.2.2.1;9.2.1 Viscosity of Plastics;237
7.2.2.2;9.2.2 Thermodynamics;239
7.2.2.3;9.2.3 Flow of Plastics;240
7.2.3;9.3 State-Of-The-Art and Challenges of Micro Injection Molding Simulations;242
7.2.4;9.4 Best Practice Strategies for Micro Molded Component Simulations;244
7.2.4.1;9.4.1 Modeling;244
7.2.4.2;9.4.2 Meshing;247
7.2.4.3;9.4.3 Material Data;248
7.2.4.4;9.4.4 Validation and Verification;250
7.2.5;9.5 Examples of Simulation-Aided Design and Simulated Phenomena;253
7.2.5.1;9.5.1 Gate Design Optimization;254
7.2.5.2;9.5.2 Hesitation Effect;257
7.2.6;9.6 Conclusions;258
7.2.6.1;References;259
7.3;10 Metrological Quality Assurance in Micro Injection Molding;263
7.3.1;10.1 Introduction;263
7.3.2;10.2 Quality of the Measurement Process: Calibration and Traceability;264
7.3.2.1;10.2.1 Accuracy and Precision;266
7.3.2.1.1;10.2.1.1 Repeatability and Reproducibility;267
7.3.3;10.3 Metrology for Micro Injection Molding;268
7.3.3.1;10.3.1 Dimensional Metrology;268
7.3.3.2;10.3.2 Surface Metrology;272
7.3.3.2.1;10.3.2.1 Areal Topography Measurements;274
7.3.4;10.4 Instrumentation for Micro Injection Molded Parts and Micro Injection Molding Tools;279
7.3.4.1;10.4.1 Optical Instruments;292
7.3.5;10.5 Uncertainty of Dimensional and Surface Topography Measurements of Micro Molded Parts and Micr;299
7.3.5.1;10.5.1 Assessment of the Uncertainty for Micro Injection Molding Applications;304
7.3.5.2;References;306
7.4;11 Additive Manufacturing for Micro Tooling and Micro Part Rapid Prototyping;311
7.4.1;11.1 Additive Manufacturing Process Technologies and Materials;311
7.4.1.1;11.1.1 Additive Manufacturing Methods for Polymer Materials;315
7.4.1.2;11.1.2 Additive Manufacturing Methods for Metal Materials;317
7.4.2;11.2 Additive Manufacturing Technologies for Micro Tooling;319
7.4.2.1;11.2.1 AM Technologies for Micro Injection Molding Hard Tooling Applications;320
7.4.2.2;11.2.2 AM Technologies for Micro Injection Molding Soft Tooling Applications;321
7.4.2.3;11.2.3 Indirect Methods for Micro Tooling Production;325
7.4.3;11.3 Additive Manufacturing for the Direct Manufacturing of Micro Products;328
7.4.3.1;References;332
8;PART 4;337
8.1;12 Micro Powder Injection Molding;339
8.1.1;12.1 Introduction;339
8.1.2;12.2 Process Description;341
8.1.2.1;12.2.1 Feedstocks for Powder Injection Molding;341
8.1.2.1.1;12.2.1.1 Binder;341
8.1.2.1.2;12.2.1.2 Powder Particle Properties;342
8.1.2.1.3;12.2.1.3 Feedstock Preparation and Rheological Properties;343
8.1.2.2;12.2.2 Debinding;343
8.1.2.3;12.2.3 Sintering;344
8.1.3;12.3 Powder Injection Molding of Micro Components (MicroPIM);344
8.1.3.1;12.3.1 Dissimilarities between Powder and Plastics Injection Molding;345
8.1.3.2;12.3.2 Dissimilarities between Macro- and MicroPIM;346
8.1.4;12.4 2C Powder Injection Molding;350
8.1.5;12.5 Simulation of MicroPIM;352
8.1.5.1;12.5.1 MicroPIM Simulation by Use of Commercial Programs;352
8.1.5.2;12.5.2 MicroPIM Simulation Using Modified or Newly Developed Software Programs;353
8.1.6;12.6 Summary and Outlook;355
8.1.6.1;References;356
8.2;13 Multimaterial Micro Injection Molding;361
8.2.1;13.1 Introduction;361
8.2.2;13.2 Multimaterial Molding and Multimaterial Micro Molding;362
8.2.2.1;13.2.1 Introduction and Applications;362
8.2.2.2;13.2.2 Application Areas;365
8.2.2.3;13.2.3 Advantages and Disadvantages;366
8.2.2.4;13.2.4 Variants of Multimaterial Molding;367
8.2.3;13.3 Two-Component Micro Molding;368
8.2.3.1;13.3.1 Polymer–Polymer Bonding;369
8.2.3.1.1;13.3.1.1 Hypotheses on Adhesion of 2K Molded Polymers;371
8.2.3.1.2;13.3.1.2 Experimental Investigations and Results;373
8.2.3.1.3;13.3.1.3 Other Factors Affecting Bonding between Polymers;380
8.2.3.1.4;13.3.1.4 Effects of Surface Roughness on the Bonding of Two Polymers;381
8.2.3.1.5;13.3.1.5 Effects of Environmental Factors;383
8.2.3.2;13.3.2 Polymer–Polymer Interface;386
8.2.3.2.1;13.3.2.1 Challenges for 2K Injection Molding: Bonding and Interface Dilemma;387
8.2.3.2.2;13.3.2.2 Special Considerations for the Polymer–Polymer Interface of Micro Parts;391
8.2.4;13.4 Adhesion Modification for Multicomponent Molding;392
8.2.5;13.5 Other Quality Issues for Multicomponent Micro Molding;394
8.2.6;13.6 Conclusion;395
8.2.6.1;References;397
9;Index;400

Leseproben

1 Micro Injection Molding Machines Technology Gualtiero Fantoni, Donata Gabelloni, Guido Tosello, Hans N. Hansen 1.1 Introduction The present chapter introduces the design of micro molding machines from two different perspectives: analysis of patents on the technology, and design architectures and solutions for the micro injection molding machines. The first analysis is oriented to provide a quantitative scenario on the attempts to exploit research for commercial uses, and it is performed taking into account patents applications worldwide. It helps in situating the micro injection molding domain in the industrial market (particularly on the machine manufacturing side). Conversely, the second part of the present chapter focuses on some relevant architecture aspects of micro injection molding machines that have been analyzed from a functional perspective. The choice of the machines is based on interesting architectures that have been the target of various researches in the recent past and that are often cited within the present book. 1.2 Patent Analysis Patents data can provide an overview of the main technologies related to an artifact. A landscape study of the patents concerning micro injection molding machines and their components has been performed. Such study identified a patent set selected from a patent database provided by Erre Quadro s. r.l. (http://www.errequadrosrl.com/). The patent set contains 2809 individual patents. They cover a period of 135 years and have been filed by more than 500 assignees coming from 17 countries. Many of them (>75%) belong to the last two decades, when patents and their use increased thanks to the internet adoption and patent spread. Different analyses have been carried out on the selected patent set. First, a linguistic analysis has been performed to identify expressions (i. e., multi-word terms) that are specific to the particular patent set. Figure 1.1 illustrates the most relevant expressions used in the patent set on micro injection molding machines. The size of the expressions within the tag cloud is proportional to their frequency of occurrence in the selected patent set. The tag cloud reports many of the components of the machines and a particular interest in the mold cavity as a key element in the specific case of micro injected components. Figure 1.1 Tag cloud in the patent set on micro injection molding machines Patents filed in states that are members of the World Intellectual Property Organization (WIPO) are assigned, by the patent office, to one or more IPC 1 classes. Thus, each IPC class can be interpreted as a corresponding technological area. Table 1.1 provides a list of the 10 largest IPC classes within the investigated set of patents. As expected, the main topics are those related to techniques for “working plastic” and “organic macromolecular compounds” of various origins. Table 1.1 Main 10 IPC Classes Sorted According to Occurrence within Patent Set Class Class description B29C working of plastics; working of substances in a plastic state in general, shaping or joining of plastics; shaping of substances in a plastic state in general; after-treatment of the shaped products B22D casting; powder metallurgy; casting of metals; casting of other substances by the same processes or devices B29B working of plastics; working of substances in a plastic state in general; preparation or pretreatment of the material to be shaped; making granules or preforms; recovery of plastics or other constituents of waste material containing plastics B29L working of plastics; working of substances in a plastic state in general indexing scheme associated with subclass B29C, relating to particular articles C08J organic macromolecular compounds; their preparation or chemical working-up; compositions based thereon working-up; general processes of compounding B29K working of plastics; working of substances in a plastic state in general indexing scheme associated with subclasses B29B, B29C, or B29D, relating to molding materials or to materials for reinforcements, fillers, or preformed parts C08L organic macromolecular compounds; their preparation or chemical working-up; compositions based thereon; compositions of macromolecular compounds C08K organic macromolecular compounds; their preparation or chemical working-up; compositions based thereon; use of inorganic or non-macromolecular organic substances as compounding ingredients H01L basic electric elements; semiconductor devices; electric solid state devices B29D working of plastics; performing operations; transporting/producing particular articles from plastics or from substances in a plastic state (making granules B29B 9/00; making preforms B29B 11/00) Figure 1.2 shows how patents are distributed in time according to filing date. Referring to such figure, the distribution shows a growing trend (more regular with respect to other machines and disciplines) but with several fluctuations and some anomalies (e. g., the year 2000). Figure 1.2 Temporal distribution according to filing date An important remark concerning Figure 1.2: patents become accessible to the public only after publication, which on average takes place about 18 months after a patent has been filed. During this period patents undergo examination by a patent office. This may explain, at least in part, the noticeable drop that can be seen in the last two years. Some of the most important information that can be extracted from patents meta-data is related to the companies that own the property of the patents, i. e., the assignees. The top 10 assignees found in the patent set are shown in Table 1.2. Table 1.2 Assignees: Top 10 List Top assignee % Patents Nissei Plastic Ind. Company 4.2% Toshiba Mach. Company 2.7% Sumitomo Heavy Industries 2.6% Moldmasters 2.4% Husky 1.5% Fanuc 1.4% Ube Ind. 1.2% Dai Nippon Printing Company 1.1% Yoshida Kogyo 1.0% Toyota Motor Corporation 1.0% The values of the percentages of patents owned by each assignee show that the patent ownership is rather spread and there is not a big player that has a remarkable fraction of patents. However, Nissei Plastic Ind. Company is the most relevant, followed by Toshiba Mach. Company and Sumitomo Heavy Industries. Such distribution is typical of innovative products built on the basis of pre-existing technologies and where innovation and disruption happen mainly within the companies’ R & D division. Additional interesting information concerns where the assignees of the patents are located (such data are different from the headquarters of multinational companies but often refer to the plant or division where the invention has been conceived and tested). However, before presenting the geographical distribution, it is important to notice that assignees can be further distinguished in two categories: public and private. Public assignees are institutions or organizations like universities and research centers. Private assignees are companies and individuals. Figure 1.3 and Figure 1.4 show the concentration of private and public assignees, respectively. The different colors in the images represent the different concentrations of assignees. Therefore, in Figure 1.3 the light blue areas represent a smaller number of private assignees than the dark blue regions. Similarly, in Figure 1.4, the red areas reveal the countries where a high number of public assignees filed patents, with respect to the green ones. Figure 1.3 Geographical distribution of private assignees in the reference patent set.
The figure is presented in the color supplement Figure 1.4 Geographical distribution of public assignees in the reference patent set.
The figure is presented in the color supplement The analysis reveals that the highest concentration of private assignees—in terms...