HANDBOOK OF PLASTICS TESTING AND FAILURE ANALYSIS, FOURTH EDITION by VISHU SHAH

HANDBOOK OF PLASTICS TESTING AND FAILURE ANALYSIS

FOURTH EDITION

VISHU SHAH

Consultek
Diamond Bar, California







Logo: Wiley

PREFACE TO THE FOURTH EDITION

Plastics testing technology, like all other evolving technologies, is dynamic in its principle. Even the well‐established tests get continual refinement. The advent of computers, robotics, and other advanced manufacturing technologies has contributed to the simplicity, accuracy, automation, and speed of testing. A lot has evolved since the third edition. Notable and dramatic changes have taken place in test equipment. They are in response to the demand from the material suppliers, compounders, processors, manufacturers, and end‐users. The explosive growth of the plastics industry has left a void in terms of recruiting trained technicians to conduct the tests in a meaningful way. The equipment suppliers have developed comprehensive technology that includes more sophisticated equipment that is capable of performing tests without much intervention and also analyze the data and present results in an easy‐to‐interpret format.

Accordingly, the fourth edition seeks to update the chapters in line with the latest developments that include the revisions to the testing procedures, photographs showing the newer version of commercially available equipment, useful data, and references. The appendix section has been revised extensively. The evolution of science and technology‐based search engines has made finding the listing of standards and comparing property values relatively more straightforward, thus eliminating the need for the printed version. Appendix pointing the readers to information sources on the web along with the Links to Recommended open source for quick learning is added.

Included with the third edition was a DVD containing numerous color photographs, depicting photoelastic analysis, color theory, and animations along with a virtual tour of the plastics testing laboratory. This has been moved to online access with the latest revisions. In line with the primary objective of this book of providing a hands‐on reference for the novice and professionals, a new feature is added. The readers will have access to the supplementary website containing color photographs, animations, videos, and a problem‐solution manual.

Once again, I wish to express thanks to all the users of previous editions for their constructive comments and helpful suggestions for changes and improvements for the next edition and to those who helped with this revision. In particular, I wish to thank Rich Goshgarian, Francesca Pinto of Instron Corporation, Al Zielnik of Atlas Material Testing, Jim Galipeau of Intertek, Mike Bradley of Thermo Fisher Scientific, Joel Feingold and Tim Wilson of Strainoptics, Inc., Patrick Burke of Jordi Labs, and Sandra Weixel of BYK‐Gardner. Many thanks to Dr. Todd Menna of Element Materials Technology for his invaluable contribution and all other companies for providing numerous illustrations and diagrams. Lastly, I would like to thank the publisher and the staff, especially Jonathan Rose and Aruna Pragasam, for guiding me and patiently waiting for me to complete the revision, which took much longer than anticipated.

I would be remiss if I did not by all rights thank my caring, loving, and supportive wife Charlene, my lovely daughter Beejal, and my son Neerav and his soul mate Hiral for their support and encouragement.

Vishu Shah
Consultek, LLC
Diamond Bar, CA

PREFACE TO THE THIRD EDITION

During the period that elapsed between the second edition and the date of writing of this third edition, the author shifted his career from a full‐time molder to a full‐time Consultant/Expert witness/Educator. The opportunity existed for analyzing numerous plastic‐part‐related premature failures. Failure analysis and testing go together. In order to analyze the failure, it is often necessary to conduct tests. In this third edition, therefore, the decision was made to expand the current chapter on failure analysis substantially and alter the title of the book to Handbook of Testing and Failure Analysis to reflect the change appropriately.

Existing books and literature on the subject of failure analysis are too complex, too detailed, sometimes difficult to understand, and more suitable to the persons well‐versed in polymer chemistry and physics. This book attempts to simplify a rather difficult subject of failure analysis by focusing on four major types of failures and key reasons behind failure of plastic parts. A step‐by‐step procedure starting from very basic and simple visual analysis to highly advanced analytical tests is presented. A simple flow chart is included to help with the investigation. To assist with the understanding of the subject matter, several actual case studies are included. This simple approach to analyzing failures is not intended primarily for a specialist but for those who wish to acquire basic knowledge and understanding of the failure mechanism. The author’s aim is not to replace excellent books that are in existence on this subject but to supplement and pave the road for more detailed and sophisticated failure analysis techniques in existence today.

All other chapters in the book have been updated with the latest information, diagrams, and photographs of the test equipment. The Appendix section has been updated. Appendix I, which listed the properties of the most common plastics, elastomers, and rubbers in the early edition, has been replaced with information about four major electronic databases for plastic materials. In order to increase the versatility of the book, numerous color photographs depicting photoelastic analysis and color theory along with various animations have been added on to the compact disk that is included with the book. More importantly, a virtual tour of a prominent Plastics Testing Laboratory is included to give the reader an opportunity to visit the laboratory from his or her desk and learn and understand how the tests are conducted and data are collected.

The author wishes to express thanks to all the users of previous editions for their constructive comments and helpful suggestions for changes and improvements for the next edition and to those who helped with this revision. In particular, he wishes to thank Jim Beauregard and Jim Galipeau of Plastics Testing Laboratory for their invaluable contribution, agreeing to the novel concept of virtual laboratory tour and making it possible. The author also wishes to thank Gerard Nelson of Ceast USA, GE Plastics, Kishor Mehta of Plascon Associates, Bayer Corporation, Dr. Alex Redner of Strainoptics, Inc., Paul Gramann of The Madison Group, Jim Rancourt of Polymer Solutions, and Steve Ferry of Micobac Laboratories. Many thanks to Steve Tuszynski of Algoryx for his contribution and to all other companies for providing numerous illustrations and diagrams. The book by Myer Ezrin, Plastics Failure Guide, Causes and Prevention, has been an important and valuable source of theoretical and practical information, and the author highly recommends his book for more detailed and in‐depth discussion of the subject.

Once again, I would like to thank my family for their encouragement and constant support.

Vishu Shah
Consultek, LLC,
Brea, CA

PREFACE TO THE SECOND EDITION

Since the publication of the first edition, little has changed as far as the basic concepts and methods of plastics testing. What has changed is the manner in which the data is collected and analyzed. Since the advent of computers and digital instruments, data collection and subsequent analysis and interpretation have become much simpler and faster.

This revised edition attempts to update the book in line with the latest developments in the field of testing, data acquisition, and analysis. The photographs depicting the commercially available testing equipment have been replaced with newer versions. A new chapter covering uniform global testing standards has been added. This chapter also includes current information about computerized material selection, which allows the user to compare various test data and material ranking based on the test data with utmost speed and ease. the entire section on impact properties has been rewritten to include an expanded discussion of instrumented impact testing. The chapters on electrical weathering properties and material characteristics have been revised. Owing to significant changes and developments in flammability testing this chapter has also been updated. The chapter on failure analysis is expanded significantly to further satisfy the need of someone trying to determine a failure mechanism. The discussion on SQC/SPC in the chapter on quality control has been expanded along with the current trend toward “supplier certification.” The chapter on nondestructive testing has also been rewritten to include many other NDT techniques and the latest developments. The Appendix has been expanded to include plastics education degree programs and organizations. The list of test equipment suppliers has been updated and now includes appropriate web site addresses. The specification section includes ISO test method designations and ASTM/DOD cross references.

The author wishes to thank all those who helped to make this second edition possible for their constructive and candid comments, support, and guidance. In particular he wishes to thank professor Steven Driscoll (University of Massachusetts Lowell) and Professor Robert Speirs (Ferris State University) for their suggestions and guidance. Special thanks to R. Bruce Cassel of Perkin‐Elmer and Kurt Scott of Atlas Electric Devices Company for reviewing and improving the manuscript and to Steve Caldarola of SGS–U.S. Testing who assisted in updating the chapter on flammability. I wish to thank Peter Grady of Ceast U.S.A., John Dechristofaro of Dynisco–Kayeness, Brookfield Engineering, G.E. Plastics, Society of Plastics Industry, Instron Corporation, Underwriters Laboratories, Strain Optics, D.A.T.A. Publishing, Newport Scientific and many others for providing technical assistance and photographs for reproduction. Many thanks to James Galipeau and Mr. James Beauregard of Plastics Testing Laboratories for providing material on advances in plastics testing and for reviewing the entire manuscript.

Last, but not least, I thank my wife Charlene, my son Neerav, and my daughter Beejal for their understanding and patience during many evenings and weekends when I was wrapped up in the preparation of this revised edition.

Vishu Shah
Performance Engineered Products, Inc.
Pomona, California

PREFACE TO THE FIRST EDITION

The desire to compile this book was initiated mainly because of the virtual non‐existence of a comprehensive work on testing of plastic materials. The majority of the literature concerning the testing of plastics is scattered in the form of sales and technical brochures, private organizations’ internal test procedures, or a very brief and oversimplified explanation of the test procedures in plastics literature. The main objective of the present book is to provide a general purpose practical text on the subject with the main emphasis on the significance of the test or why and not so much on how without being extremely technical.

Over the years ASTM (American Society for Testing and Materials) has done an excellent job in providing the industry with standard testing procedures. However, the test procedures discussed in ASTM books lack the theoretical aspects of testing. The full emphasis is not on significance of testing but on procedures of testing. The ASTM books are also deficient in showing the diagrams and photographs of actual, commercial testing equipment. In this book I have tried to bridge the gap between the oversimplified and less explained tests described in ASTM books and the highly technical and less practical books in existence today.

This handbook is not intended primarily for specialists and experts in the area of plastics testing but for the neophyte desiring to acquire a basic knowledge of the testing of plastics. It is for this reason that detailed discussions and excessive technical jargon have been avoided. The text is aimed at anyone involved in manufacturing, testing, studying, or developing plastics. It is my intention to appeal to a broad segment of people involved in the plastic industry.

In Chapter 1 the basic concepts of testing are discussed along with the purpose of specifications and standards. Also discussed is the basic specification format and classification system. The subsequent chapters deal with the testing of five basic properties: mechanical, thermal, electrical, weathering, and optical properties of plastics. The chapter on mechanical properties discusses in detail the basic stress–strain behavior of the plastic materials so that a clear understanding of testing procedures is obtained. Chapter 7 on material characterization is intended to present a general overview of the latest in characterization techniques in existence today. A brief explanation of the polymer combustion process along with various testing procedures are discussed in Chapter 8. An attempt is made to briefly explain the importance of conditioning procedures. A table summarizing the most common conditioning procedures should be valuable. Several tests that are difficult to incorporate into a specific category were placed in the chapter on miscellaneous tests. End‐product testing, an area generally neglected by the majority of processors of plastic products, is discussed along with some useful suggestions on common end‐product tests.

Chapter 13 on identification analysis should be important to everyone involved in plastics and particularly useful to plastic converters and reprocessors. The flowchart summarizes the entire identification technique. Since there are so many different tests in existence on the testing of foam plastics, only a brief explanation of each test is given. The chapter on failure analysis is a compilation of methods commonly used by material suppliers. A step‐by‐step procedure for analyzing product failure should prove valuable to anyone ivolved in failure analysis. Quality control, although not part of the testing, is included in order to explain quality control as it relates to plastics. The section on visual standard, mold control, and workmanship standard is a good example. In this increasing world of product liability, the chapter on product liability and testing should be of value to everyone.

In order to increase the versatility of this book and meet the goal of providing a ready reference on the subject of testing, a large appendix section is given. One will find very useful data: names and addresses of equipment manufacturers, a glossary, names and addresses of trade publications, information on independent testing laboratories, and a guide to plastics specifications. Many useful charts and tables are included in the appendix. Throughout the book, wherever possible, numerous diagrams, sketches, and actual photographs of equipment are given.

A handbook of this magnitude must make inevitable compromises. Depending on the need of the individual user, there is bound to be a varying degree of excess and shortage. In spite of every effort made to minimize mistakes and other short‐comings in this book, some may still exist. For the sake of future refinement and improvements, all constructive comments will be welcomed and greatly appreciated.

Vishu Shah
Pomona, California
October 1983

BIOGRAPHY OF VISHU SHAH