Handbook of Troubleshooting Plastics Processes E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 829

Veröffentlichungsjahr: 2012

Beschreibung

This handbook provides a framework for understanding how to characterize plastic manufacturing processes for use in troubleshooting problems. The 21 chapters are authored by well-known and experienced engineers who have specialized knowledge about the processes covered in this practical guide. From the Preface: "In every chapter, the process is described and the most common problems are discussed along with the root causes and potential technical solutions. Numerous case studies are provided that illustrate the troubleshooting process. Mark A. Spalding, The Dow Chemical Company

Leseprobe

Contents

Cover

Half Title page

Title page

Copyright page

Preface

List of Contributors

Part 1: Troubleshooting Basics

Chapter 1: The Economics of Troubleshooting Polymer Processing Systems

1.1 Introduction

1.2 Economic Incentives and Necessities

1.3 Troubleshooting Resources and Their Cost

1.4 Managing Resources and Costs

1.5 Troubleshooting Techniques and Their Relative Costs

1.6 Case Histories

1.7 Conclusions

References

Chapter 2: Troubleshooting Philosophy

2.1 Introduction

2.2 Troubleshooting Methodology

Bibliography

Chapter 3: Statistical Tools for Trouble Shooting a Process

3.1 Introduction

3.2 Basic Statistical Concepts

3.3 Sample Mean and Standard Deviation

3.4 Design of Experiments (DOE)

3.5 Process Capability

3.6 Control Charts

References

Bibliography

Part 2: Extrusion Processes

Chapter 4: Single Screw Extrusion

4.1 Introduction

4.2 Process Description

References

Chapter 5: Troubleshooting the Co-rotating Fully Intermeshing Twin-screw Compounding System

5.1 Introduction

5.2 Equipment Description

5.3 Troubleshooting

5.4 Tools of the Successful Troubleshooter

5.5 Product, Process and Equipment Knowledge

5.6 Conclusion

References

Chapter 6: Troubleshooting for Injection Molding

6.1 Introduction

6.2 Understanding Temperature Control

6.3 Product Shift to a Different Machine

6.4 Part Weight as an Analytical Tool

6.5 Part Weight as Dimensional Aimpoint Control

6.6 Determining the Gate Freeze-Off Time

References

Chapter 7: Blown Film

7.1 Introduction

7.2 Process Description

7.3 Special Tools for Troubleshooting

7.4 Case Studies

References

Chapter 8: Cast Film Troubleshooting

8.1 Coextrusion Film Systems

8.2 Troubleshooting Method

8.3 Common Problems, Hypotheses and Tests

References

Chapter 9: Oriented Films-Troubleshooting and Characterization

9.1 Introduction

9.2 Process Overview: Biaxial Orientation

9.3 Oriented Film Markets

9.4 Troubleshooting the Film Orientation Process as Applied to OPP Films

9.5 Special Tools for Troubleshooting

9.6 Case Studies

References

Bibliography

Chapter 10: Troubleshooting the Thermoforming Process

10.1 General Concepts in Thermoforming

10.2 Categorization of the Process

10.3 Specific Aspects of the Thermoforming Process

10.4 Problem Solving Methodology

10.5 General Preventative Maintenance Concepts

10.6 General Predictive Maintenance Concepts

10.7 Safety during Troubleshooting

Appendix 1: Thermoforming References with Troubleshooting Sections

Appendix 2: Plastic Materials References

Appendix 3: Troubleshooting Guidelines for Thick-Gauge Thermoforming (abstracted from [1], [10], and [13]).

Appendix 4: Troubleshooting Guidelines for Thin-Gauge Thermoforming (abstracted from [1, 9, 10, 14]).

Appendix 5: Time-dependent Ranking of Typical Courses of Action (Note: Change only one parameter at a time!)

Appendix 6: Troubleshooting Guidelines for Trimming Parts (abstracted from [10], [13], and [14]).

Chapter 11: Proper Equipment Processing for Industrial/Technical Blow Molding

11.1 Introduction of Blow Molding

11.2 Select the Proper Equipment

11.3 Extruder

11.4 Accumulator Head

11.5 Importance of Cleaning

11.6 Press

11.7 Hydraulics

11.8 Microprocessor

11.9 Pneumatic Systems

11.10 Part Take Out System

11.11 Selection of Equipment

Chapter 12: PET Stretch Blow Molding

12.1 Introduction

12.2 The PET Universe

12.3 Technology History

12.4 PET Chemistry

12.5 PET Morphology

12.6 Bottle Universe

12.7 Bottle Manufacturing

12.8 Commercial Manufacturing Processes

12.9 Process Elements

12.10 Case Sample: Thermal Stability Failure of CSD Bottles

References

Chapter 13: Blow Molding – Problems and Solutions

13.1 Introduction

13.2 Troubleshooting

13.3 Variables Affecting the Blow Molding Process

13.4 Preventative Maintenance

13.5 Injection and Stretch Blow Molding

13.6 Computer Integrated Manufacturing (CIM) in Extrusion Blow Molding

Acknowledgement

Bibliography

Chapter 14: Extrusion Coating Troubleshooting

14.1 Coextrusion Extrusion Coating/Laminating Systems

14.2 Troubleshooting Method

14.3 Common Problems, Hypotheses and Tests

References

Part 3: Non-Extrusion Processes

Chapter 15: Adhesive and Thermal Lamination

15.1 Introduction

15.2 Process Description

15.3 Control Variables

15.4 Random Cause Variables

15.5 Dependent Variables

15.6 Special Tools for Troubleshooting

15.7 Case Studies

Bibliography

Chapter 16: Troubleshooting for Rotomolding

16.1 The Basic Process

16.2 Key Quality Control Steps in Rotomolding

16.3 Typical Rotomolding Problems

16.4 Typical Solutions

Chapter 17: Plastics Calendering

17.1 Introduction

17.2 Blending and Fluxing

17.3 Mills and Strainers

17.4 Calender

17.5 General Description of a Calendering Machine

17.6 The Calendering Process

17.7 Input Materials and Products

17.8 Why Calendering is Preferred to Extrusion

17.9 Calendering Process Variables

17.10 Conclusion

References

Bibliography

Chapter 18: Compression Molding

18.1 Introduction

18.2 Materials

18.3 Sheet Molding Compound – Production

18.4 Technology – Compression Molding

18.5 Troubleshooting

18.6 Problems and Solution(s)

18.7 Summary

References

Chapter 19: Transfer Molding

19.1 Introduction

19.2 Curing

19.3 Processing

19.4 Mold

19.5 Process Optimization

19.6 Method

19.7 Pot Type Transfer Molding

19.8 Troubleshooting

19.9 Summary

References

Chapter 20: Pultrusion Process Troubleshooting

20.1 Introduction

20.2 Materials Review

20.3 Process Parameters

20.4 Manufacturing Defects

20.5 Material Related Defects

20.6 Process Parameter Related Defects

20.7 Methods Related Defects

20.8 The Troubleshooting Process

20.9 Troubleshooting Examples

20.10 Summary

Acknowledgement

References

Chapter 21: Troubleshooting Static Problems in Plastics Processes

21.1 Introduction

21.2 Root Causes of Static

21.3 Static Measurement Tools

21.4 Static Problem Diagnosis

21.5 Solving Static Problems

References

Recommended Reading for Further Study

Handbook of Troubleshooting Plastics Processes

Scrivener Publishing100 Cummings Center, Suite 541JBeverly, MA 01915-6106

Polymer Science and Plastics Engineering

The “Polymer Science and Plastics Engineering” series publishes both short and standard length monographs, textbooks, edited volumes, practical guides, and reference works related to all aspects of polymer science and plastics engineering including, but not limited to, renewable and synthetic polymer chemistry and physics, compositions (e.g. blends, composites, additives), processing, characterization, testing, design, and applications. The books will serve a variety of industries such as automotive, food packaging, medical, and plastics as well as academia.

Series Editor: Srikanth Pilla, PhDWisconsin Institute for DiscoveryUniversity of [email protected]

Publishers at ScrivenerMartin Scrivener ([email protected])Phillip Carmical ([email protected])

Copyright © 2012 by Scrivener Publishing LLC. All rights reserved.

Co-published by John Wiley & Sons, Inc. Hoboken, New Jersey, and Scrivener Publishing LLC, Salem, Massachusetts.Published simultaneously in Canada.

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Library of Congress Cataloging-in-Publication Data:

ISBN 978-0-470-63922-1

Preface

The goal of all troubleshooting operations is to restore the process to its original performance as quickly as possible with the least amount of cost. If the process is operational and producing a high level of off specification product, then the manufacturing costs can be very high. Restoring the line to its original performance quickly will reduce costs by eliminating some quality control operations and labor wasted in making product that is not fit for use, reducing resin consumption, eliminating recycle due to off specification product, and decreasing energy consumption. Moreover, if the line is inoperable due to the defect, the line downtime can be extremely costly, especially if the line is sold out. In this latter case, the goal would be to bring the line back to production operation as quickly as possible. Often, several different technical solutions will be possible. The best technical solution will be based on a combination of the cost of lost production, the time and cost to implement, machine owner acceptance, and the risk associated with the modified process.

This book provides a very practical guide to the troubleshooting of the most commonly used polymer processing operations, including injection molding, extrusion, films, blow molding, calendaring, lamination, and pultrusion. In every chapter, the process is described and the most common problems are discussed along with the root causes and potential technical solutions. Numerous case studies are provided that illustrate the troubleshooting process. Several additional chapters provide supporting information including statistics, economics, static electricity, and general troubleshooting. All chapters were written by expert troubleshooters with years of experience in their field.

The book was written for engineers and technologists that are performing troubleshooting operations on the plant floor. It provides the approach required for solving these types of problems quickly. The book provides key information for both the beginning and seasoned troubleshooters.

Mark A. SpaldingThe Dow Chemical Company

List of Contributors

Paul Andersen is the Director of Process Technology for Coperion Corporation, Ramsey, NJ. He is responsible for process engineering and new technology development for twin-screw extrusion/compounding. He has 35 years of industrial experience and holds several patents related to twin-screw compounding.

Chellappa Chandrasekaran obtained his BS from the American College, Madras University, India in the 60s and thereafter his Licentiateship from the Institution of Rubber Industry (London), now IOM3 (Institute of Materials, Minerals and Mining). He has served corporate and defense sectors for more than four decades in a senior capacity and has had several technical papers published in leading national and international journals. He is an author of four books in the advanced area of Rubber Technology published by leading publishers in the USA, UK and India. He has travelled widely in the Far East, and the West in North America and Canada. Presently he is CEO of Can C Consulting India.

Andrew Christie is President of Optex Process Solutions, Inc., the consulting group he founded in 2002. Optex provides extrusion process support, troubleshooting and training, and also machinery audits and upgrades for converters in thin film extrusion (cast film, blown film, and extrusion coating). In 2009 he became Managing Director of SAM North America, the subsidiary company established to support the growing business of Sung An Machinery in North & South America. Andy holds a BS in mechanical engineering from Rochester Institute of Technology. After several years in product design and development outside the extrusion processing field he joined the Black Clawson Company as an extrusion systems design engineer. Over his 15 years at Black Clawson he advanced in design and applications engineering positions to eventually lead the extrusion group as Extrusion Business Unit Manager. He left Black Clawson in 2001 to form Optex. He is active in the SPE Flexible Packaging Division where he serves as Division Chairman and has also been active in the TAPPI PLACE division where he received the Technical Merit Award in 2006 for contributions to the industry. He is a frequent presenter at technical conferences on a variety of extrusion topics. Andy was awarded three US Patents for extruder feedscrew and feedblock design.

Thomas Dunn has over thirty years’ experience developing and applying flexible packaging laminations for consumer products. He has served in leadership roles for several industry and trade associations. He is a frequent speaker and writer for industry forums.

Beth Foederer has been in the converting industry for 23 years. She has a BS in mechanical engineering, a masters in manufacturing engineering and is a licensed Professional Engineer in the State of New York. She worked for the Black Clawson Converting Systems Division of Davis Standard, LLC for over 18 years. She has been working since 2008 as a principle engineer for Optex Process Solutions, Inc. doing consulting work for the plastics industry.

Steve Gammell is the Area Sales Manager for Macro Engineering & Technology (US) Inc.

Rich Kanarski is a process engineer at Coperion Corporation. He holds a BS degree in chemical engineering from New Jersey Institute of Technology. He has been a part of the plastics community and has been a member of the Society of Plastic Engineers for several years. Currently, Kanarski focuses on polymer processing, twin-screw extrusion technology, reactive processing, polymer rheology, and process scale up. His process development research spans various applications ranging from food to engineering plastics.

Norman C. Lee is a Blow Molding Consultant who is the author of text books and a video that are used in his SPE courses. He has two decades in the plastic industry with experience in blow molding, injection molding, thermoforming and rotational molding. His main focus for the last twenty years has been in blow molding. Norman Lee has been granted 30 US and foreign patents and has been active in SPE in the Plastic Recycling and Blow Molding Divisions.

Eldridge M. Mount, III is an independent consultant in the field of extrusion, coextrusion, cast and oriented films since 2000. In addition he is an expert in high barrier film metallization and oriented coextruded film product and process design. Originally a synthetic chemist he received a PhD in chemical engineering from Rensselaer Polytechnic for the study of polymer melting in extrusion in 1979. Since 1978 he has worked in the field of oriented polyester and propylene film research and manufacturing.

Paul Nugent is an international consultant who has specialized for the past 24 years in the field of rotational molding. A native of Northern Ireland living in Pennsylvania he holds a Masters of Engineering degree in aeronautical engineering and a PhD in mechanical engineering from The Queen’s University of Belfast. His work involves extensive travel across six continents assisting clients in many roles, from teaching to expert witness and from process troubleshooting to the streamlining of manufacturing operations, as well as assisting with licensing of products and technology.

Kelly Robinson founded Electrostatic Answers, an engineering consulting company dedicated to eliminating injury and waste from static electricity. Kelly is a Professional Engineer, earned his PhD in electrical engineering from Colorado State University, and is a Fellow of the IEEE. He has worked for over 20 years solving static problems in manufacturing operations and holds 13 patents on static control and copier technology. He shares insights in “Static Beat,” a monthly column on static control in Paper Film and Foil Converter, an on-line magazine for the converting industry.

Robert Slawska has more than 45 years’ experience in industrial blow molding. He founded Sterling Blow Molding Division in 1978. In 1994, he started his consulting firm, Proven Technology Inc. Mr. Slawska was awarded the Honored Service Member in 1998 from SPE. He received SPE’s Lifetime Achievement Award for Blow Molding in 2002. In March 2012, he became a member of The Plastics Pioneers Association.

Muralisrinivasan Subramanian is a plastics technology consultant specializing in materials, additives, and processing equipment, including troubleshooting. He obtained his BS in chemistry from the Madurai Kamaraj University and his MS (1988) in polymer technology from Bharathiar University. He received his Post Graduate Diploma in Plastics Processing Technology from CIPET, Chennai and completed his Doctor of Philosophy in Polymer Science from Madurai Kamaraj University. He has worked in the plastic process industry, mainly in R & D, for 13 years before turning to consultancy and building up an international client base. Muralisrinivasan teaches plastics processing seminars as well as being a Board of Studies Expert member of colleges in India dealing with curriculum of technology subjects. He authored Update on Troubleshooting in Thermoforming in 2010, Basics of Troubleshooting in Plastics Processing in 2011, Troubleshooting in PVC Extrusion Process and Polymer Testing – New Instrumental Method.

Joseph E. Sumerak holds BS and MS Engineering degrees from Case Western Reserve University’s Polymer Science program and has 38 years of experience in the pultrusion industry. His career focus has included equipment and tooling design and manufacturing, process optimization and new product development. He has been a principal of several firms including Pultrusion Technology, Inc., Pultrusion Dynamics and currently Sumerak Pultrusion Resource.

James L. Throne is an international consultant in plastics process engineering, with emphasis on thermoforming, foam processing, and powder processing. Prior to founding Sherwood Technologies in 1985, Jim held senior research positions at several major plastics corporations and teaching positions at several universities. He is author/coauthor of more than two hundred technical papers, more than a dozen book chapters, more than a dozen technical books, and ten US Patents. He holds a PhD in chemical engineering from University of Delaware and was the 2000 SPE Thermoformer of the Year.

Vincent Vezza has over 35 years’ experience in industry. He is retired from Ortho Clinical Diagnostics, a Johnson and Johnson Company, and is now an independent consultant. He has held positions as Statistician, Quality Engineer and Process Engineer at Eastman Kodak Company and Ortho Clinical Diagnostics. He holds a MS degree in applied and mathematical statistics and BS degree in chemistry from Rochester Institute of Technology.

John R. Wagner, Jr. obtained his MS in chemical engineering from the University of Notre Dame in 1964, and worked in the Films Division at Mobile Chemical Company for the next 30 years. He is now a consultant in plastics products and processes. He has 23 patents to his name, is the editor of Journal of Plastic Film & Sheeting, as well as the editor or co-editor of 4 books on extrusion and packaging. John is a Fellow of the Society of Plastics Engineers and serves on the Extrusion Division and Flexible Plastics Packaging Division Boards.

Dan Weissmann is a consultant specializing in plastics and packaging. He has been involved in plastic beverage bottles development since its beginning in the 1970s. He led the startup of production of one of the first PET carbonated soft drink bottle plants and later the first US production of hot filled bottles. Dr. Weissmann has also worked in the areas of sheet extrusion and material development. He is a fellow of SPE and past board member of the Blow Molding Division and chairman of the technical program committee. He is a regular contributor to Plastic in Packaging magazine.

James J. Wenskus has been involved in processing research and development for injection molding for over 40 years. Jim began his development work at Stromberg Carlson working on telephone components and then at Eastman Kodak for 33 years, concentrating on processing very high-volume photographic components. He was one of the first Fellow’s elected by the Society of Plastics Engineers for his early work on in-cavity pressure applications and analysis and is also a Certified Plastics Technologist (CplasT). He has seven US Patents and several foreign patents. He holds a degree in chemistry from MIT.

Mark D. Wetzel is a Research Fellow for DuPont Engineering Research and TechnologyPolymer Engineering. He provides technical leadership for the DuPont Engineering function in the area of polymer process development, scale-up and analysis. He has over 32 years of experience in the areas of the fundamentals of extrusion and compounding, new product development through process innovation, polymer nanocomposites and the safe handling of nanomaterials. Mark was elected a Society of Plastics Engineers Fellow in 2008 and served as the Extrusion Division chair in 2010.

Karen Xiao was the R&D director for Brampton Engineering. Her areas of expertise are screw and die designs in multi-layer coextrusion, structure-processing-property relationships, polymer extrusion and rheology. Karen has published many papers in the area and is a frequent presenter at various industry conferences. She’s currently serving on the board of directors of the SPE extrusion division.

PART 1

TROUBLESHOOTING BASICS

Chapter 1

The Economics of Troubleshooting Polymer Processing Systems

Mark D. Wetzel

E. I. du Pont de Nemours and Company Engineering Research and Technology Wilmington, Delaware, USA

Abstract

Polymer processing is a very cost competitive, but capital intensive endeavor. Most industrial operations consist of a sequence of complex mechanical, electric and thermal components, where ingredients are combined or transformed into higher value products to be sold to customers in the market. The equipment can experience problems that can negatively impact productivity and quality. Proper investments are required in expertise, hardware and software to enable a manufacturing organization to troubleshoot and resolve these problems in order for the business to remain viable in the global marketplace. This chapter examines the economics of key aspects of polymer processing troubleshooting in order to assist the reader in making decisions about how to plan for and make strategic investments in technology and expertise in order to maintain and optimize equipment performance and manufacturing productivity.

Keywords: Extrusion, compounding, economics, troubleshooting, uptime, yield, cost, safety, productivity, facilities, equipment, process, measurement, analysis

1.1 Introduction

The industrial practice of polymer processing has become very cost competitive while requiring a capital intensive set of operations that includes synthesis (polymerization), chemical modification, compounding, and forming or shaping steps. Most systems consist of a sequence of complex mechanical, electric and thermal components, where ingredients are combined or transformed into higher value products to be sold to customers in the market. In order to establish, grow or maintain a profitable business, manufacturing assets must operate at or near peak performance levels that deliver products with consistent properties and high quality. However, polymer processing equipment does experience many problems that can negatively impact productivity and quality. Proper investments are required in expertise, hardware and software to enable a manufacturing organization to troubleshoot and resolve these problems in order for the business to remain viable in the global marketplace.

This chapter examines the economics of polymer processing troubleshooting to assist the reader in making decisions about how to plan for and make strategic investments in technology and expertise in order to maintain and optimize equipment performance and manufacturing productivity. Another objective is to show how it could cost more money or put a business at risk by avoiding the proper commitment to the resources required to identify the causes of processing problems and resolve them in a timely and economically viable way.

1.2 Economic Incentives and Necessities

Competitive industries like plastics processing demand high productivity in order to be profitable. Capital intensive manufacturing operations require high asset utilization. Key metrics can be used to quantify system economic performance and justify or track the costs of troubleshooting investments. The following measures are useful in determining the financial contribution of a process or set of resources allocated to that operation.

1.Uptime can be defined as the time that an asset is used to make a product that can be sold divided by the time that the asset is available to run:

(1.1)

The time available can include or exclude a number of normal production events. For example, annual plant shutdowns or routine, scheduled equipment overhauls may be excluded from the calculation. It is important that the uptime calculation be consistent over long times, so that performance changes can be compared with benchmarks. Depending on the process, uptime can range from 50 to over 95 percent. For example, a continuous polymerization unit can operate at uptimes from 90-95 percent. A small-lots custom compounding line may have an uptime of 50 to 65 percent. Catastrophic equipment problems, such as extruder screw and shaft breakage or motor drive failures have a serious impact on uptime. Material feed bridging, die hole freeze-off, die drips and plugged vacuum ports are examples of operational problems that also affect uptime.