Microcellular Injection Molding

628 Pages·2010·17.662 MB·English

by  Richard F. Grossman, Domasius Nwabunma(eds.)

MICROCELLULAR
INJECTION MOLDING
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WILEY SERIES ON POLYMER ENGINEERING
AND TECHNOLOGY
Richard F. Grossman and Domasius Nwabunma, Series Editors
Polyolefin Blends / Edited by Domasius Nwabunma and Thein Kyu
Polyolefin Composites / Edited by Domasius Nwabunma and Thein Kyu
Handbook of Vinyl Formulating, Second Edition \ Edited by
Richard F. Grossman
Total Quality Process Control for Injection Molding, Second Edition \
M. Joseph Gordon, Jr.
Microcellular Injection Molding \ Jingyi Xu
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MICROCELLULAR
INJECTION MOLDING
JINGYI XU
Engel Machinery
York, Pennsylvania
A JOHN WILEY & SONS, INC., PUBLICATION
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Copyright © 2010 by John Wiley & Sons, Inc. All rights reserved
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Published simultaneously in Canada
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Library of Congress Cataloging-in-Publication Data:
Xu, Jingyi.
Microcellular injection molding / Jingyi Xu.
p. cm. – (Wiley series on plastics engineering and technology)
Includes index.
ISBN 978-0-470-46612-4 (cloth)
1. Molding (Chemical technology) 2. Foamed materials. 3. Microfl uidics. I. Title.
TP156.M65X83 2010
668.4′12–dc22
2010004436
Printed in Singapore
10 9 8 7 6 5 4 3 2 1
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CONTENTS
Foreword by Lih-Sheng (Tom) Turng vii
Preface ix
1 Introduction 1
2 Basics of Microcellular Injection Molding 12
3 Morphology of Microcellular Materials 62
4 Materials for Microcellular Injection Molding 98
5 Design of Microcellular Injection Molding 165
6 Process for Microcellular Injection Molding 227
7 Equipment and Machines for Microcellular Injection Molding 314
8 Special Processes 399
9 Modeling of Microcellular Injection Molding 458
10 Postprocessing and Property Test of Microcellular
Injection Molding 506
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vi CONTENTS
11 Markets and Applications of Microcellular Injection Molding 525
12 Cost Savings for Microcellular Injection Molding 552
Nomenclature 578
Appendix A (Chapter 7) 585
Appendix B (Chapter 7) 587
Appendix C (Chapter 5) 589
Appendix D (Chapter 5) 591
Appendix E (Chapter 5) 593
Appendix F (Chapter 6) 595
Appendix G (Chapter 9) 597
Appendix H (Glossary) 600
Index 607
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FOREWORD
It is a great privilege to write the Foreword for a book that provides so much
detailed and insightful information about microcellular injection molding
technology. Injection molding is one of the most versatile and important
polymer - processing methods for mass production of complex plastic parts. In
addition to thermoplastics and thermosets, injection molding has been
extended to such materials as fi bers, ceramics, and powdered metals, with
polymers as binders. Among polymer - processing methods, injection molding
accounts for one - third by weight of all polymeric materials processed. New
variations and emerging innovations of conventional injection molding have
been continuously developed to further extend the applicability, capability,
fl exibility, productivity, and profi tability of this versatile, mass production
process. These special and emerging injection molding processes introduce
additional design freedom, new application areas, unique geometrical fea-
tures, enhanced part strength, and sustainable economic benefi ts, as well as
improved material properties and part quality that cannot be accomplished
by conventional injection molding processes. Among these special and emerg-
ing techniques, microcellular injection molding holds great promise for
improving process economics while enhancing the characteristics and func-
tionality of molded parts.
The author, Mr. Jingyi Xu, is a world - renowned expert in microcellular
injection molding due to his early and continuous involvement in the develop-
ments of this novel process that originated from the work of Dr. Suh and his
colleagues at MIT in the early 1980s. The potential benefi ts of microcellular
injection molding go beyond the apparent and attractive savings of material,
cycle time, and energy, as it also greatly boosts dimensional stability and
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viii FOREWORD
facilitates part consolidation and innovation. A wide range of commodity and
engineering resins ranging from amorphous, semicrystalline, and thermoset-
ting materials to thermoplastic elastomers and bioplastics have been success-
fully used with the microcellular injection molding process.
While there are many publications and patents related to new develop-
ments and applications of microcellular injection molding, there remains a
huge gap between process fundamentals and real - world applications. This
book bridges this gap by providing comprehensive coverage in a format that
is easy to understand and apply. It also touches on a wide range of subjects,
including historical developments, fundamental principles, applicable materi-
als, design guidelines, process comparisons, equipment design, modeling,
material properties, and commercial applications. I admire the painstaking
commitment and sheer effort of Mr. Xu in making this book a reality. His
contribution to the illumination and dissemination of process know - how
and guiding principles will be applicable for years to come. This book will
undoubtedly assist readers of various backgrounds and levels of expertise to
better understand, implement, and benefi t from this novel and promising
technology.
Polymer Engineering Center L IH - S HENG (TO M ) T URNG
University of Wisconsin — Madison
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PREFACE
Microcellular polymers can replace solid polymers with 5% or more material
reductions without compromising a signifi cant amount of material properties.
In addition, this technology yields even more benefi ts of microcellular foam
such as dimensional stability, short cycle time, elimination of sink marks and
warpage, and stress - free parts. Therefore, microcellular injection molding pro-
vides a revolutionized way to save materials, and protect the environmental.
Consequently, microcellular injection molding has become the fastest devel-
oping technology in all microcellular processes. However, most published
papers and books on foaming are not often concerned with the practical
aspects of applying this technology. This book is intended to bridge these gaps
and provides everybody engaged in the design, research, and professional
training with a reference book that covers the design and production of micro-
cellular processing in a comprehensive manner.
This book takes the available respected literature into account as well as
the real results from extended research and development works in the world.
It is my intent to include suffi cient detailed discussions for the student
pursuing, or just beginning to pursue, a career in the broad microcellular
processing arena.
The greatest appreciation should go to everyone who worked hard for this
technology. I thank Professor Lih Sheng Turng for reviewing part of my book
and for providing the Foreword for this book. Special thanks also go to
Professor Chul B. Park for providing valuable information; Levi Kishbaugh
for providing courtesy information from Trexel Inc.; and Peter Kennedy, Sejin
Han, and Xiaoshi Jin for simulation information, My co - worker Ben Keur
read this manuscript and offered excellent opinions, and many others provided
their expertise.
ix
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x PREFACE
I wish to express my appreciation to editor Jonathan T. Rose at John Wiley
& Sons, Inc., particularly for his initial idea to write this book and for his
splendid efforts during this diffi cult time to publish this book.
Additionally, I thank my daughter Jiayun Xu as a fi rst general reader with
many excellent suggestions for readability of this book. My wife Jufen Guan
also gave me unconditional support, as always.
Engel Machinery J INGYI X U
York, Pennsylvania
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