Polymer Processing

Fundamental concepts coupled with practical, step-by-step
guidance

With its emphasis on core principles, this text equips readers
with the skills and knowledge to design the many processes needed
to safely and successfully manufacture thermoplastic parts. The
first half of the text sets forth the general theory and concepts
underlying polymer processing, such as the viscoelastic response of
polymeric fluids and diffusion and mass transfer. Next, the text
explores specific practical aspects of polymer processing,
including mixing, extrusion dies, and post-die processing. By
addressing a broad range of design issues and methods, the authors
demonstrate how to solve most common processing problems.

This Second Edition of the highly acclaimed Polymer
Processing has been thoroughly updated to reflect current
polymer processing issues and practices. New areas of coverage
include:

• Micro-injection molding to produce objects weighing a fraction
  of a gram, such as miniature gears and biomedical devices

• New chapter dedicated to the recycling of thermoplastics and
  the processing of renewable polymers

• Life-cycle assessment, a systematic method for determining
  whether recycling is appropriate and which form of recycling is
  optimal

• Rheology of polymers containing fibers

Chapters feature problem sets, enabling readers to assess and
reinforce their knowledge as they progress through the text. There
are also special design problems throughout the text that reflect
real-world polymer processing issues. A companion website features
numerical subroutines as well as guidance for using
MATLAB¯®, IMSL¯®, and Excel to solve
the sample problems from the text. By providing both underlying
theory and practical step-by-step guidance, Polymer Processing is
recommended for students in chemical, mechanical, materials, and
polymer engineering.

Autorentext

DONALD G. BAIRD, PhD, is the Alexander F. Giacco and Harry C. Wyatt Professor of Chemical Engineering at Virginia Tech. His research centers on the use of fundamental non-Newtonian fluid mechanics to develop improved processing operations for polymers and polymer composites. Among his many honors, the Society of Plastics Engineers has awarded him the International Award, the International Award for Research, and the International Award for Education. A holder of seven patents, Dr. Baird has published some 300 refereed publications.

DIMITRIS I. COLLIAS, PhD, is with the corporate R&D department of the Procter & Gamble Co. in Cincinnati, Ohio. He earned his PhD degree from Princeton University. With twenty years of industry experience in polymers, polymer processing, packaging, paper, and activated carbon, his current research focuses on developing renewable materials and processes for key products in the company's portfolio. Dr. Collias holds fifty-four issued U.S. patents and is inventor or co-inventor in more than thirty U.S. patent applications.

Klappentext

Fundamental concepts coupled with practical, step-by-step guidance

With its emphasis on core principles, this text equips readers with the skills and knowledge to design the many processes needed to safely and successfully manufacture thermoplastic parts. The first half of the text sets forth the general theory and concepts underlying polymer processing, such as the viscoelastic response of polymeric fluids and diffusion and mass transfer. Next, the text explores specific practical aspects of polymer processing, including mixing, extrusion dies, and post-die processing. By addressing a broad range of design issues and methods, the authors demonstrate how to solve most common processing problems.

This Second Edition of the highly acclaimed Polymer Processing has been thoroughly updated to reflect current polymer processing issues and practices. New areas of coverage include:

• Micro-injection molding to produce objects weighing a fraction of a gram, such as miniature gears and biomedical devices
• New chapter dedicated to the recycling of thermoplastics and the processing of renewable polymers
• Life-cycle assessment, a systematic method for determining whether recycling is appropriate and which form of recycling is optimal
• Rheology of polymers containing fibers
  Chapters feature problem sets, enabling readers to assess and reinforce their knowledge as they progress through the text. There are also special design problems throughout the text that reflect real-world polymer processing issues. A companion website features numerical subroutines as well as guidance for using MATLAB®, IMSL®, and Excel to solve the sample problems from the text. By providing both underlying theory and practical step-by-step guidance, Polymer Processing is recommended for students in chemical, mechanical, materials, and polymer engineering.

Inhalt

Preface xi

Preface to the First Edition xiii

Acknowledgments xv

1 Importance of Process Design 1

1.1 Classification of Polymer Processes 1

1.2 Film Blowing: Case Study 5

1.3 Basics of Polymer Process Design 7

References 8

2 Isothermal Flow of Purely Viscous Non-Newtonian Fluids 9

Design Problem I Design of a Blow Molding Die 9

2.1 Viscous Behavior of Polymer Melts 10

2.2 One-Dimensional Isothermal Flows 13

2.2.1 Flow Through an Annular Die 14

2.2.2 Flow in a Wire Coating Die 17

2.3 Equations of Change for Isothermal Systems 19

2.4 Useful Approximations 26

2.5 Solution to Design Problem I 27

2.5.1 Lubrication Approximation Solution 27

2.5.2 Computer Solution 29

Problems 30

References 34

3 Viscoelastic Response of Polymeric Fluids and Fiber Suspensions 37

Design Problem II Design of a Parison Die for a Viscoelastic Fluid 37

3.1 Material Functions for Viscoelastic Fluids 38

3.1.1 Kinematics 38

3.1.2 Stress Tensor Components 39

3.1.3 Material Functions for Shear Flow 40

3.1.4 Shear-Free Flow Material Functions 43

3.2 Nonlinear Constitutive Equations 44

3.2.1 Description of Several Models 44

3.2.2 Fiber Suspensions 52

3.3 Rheometry 55

3.3.1 Shear Flow Measurements 56

3.3.2 Shear-Free Flow Measurements 58

3.4 Useful Relations for Material Functions 60

3.4.1 Effect of Molecular Weight 60

3.4.2 Relations Between Linear Viscoelastic Properties and Viscometric Functions 61

3.4.3 Branching 61

3.5 Rheological Measurements and Polymer Processability 62

3.6 Solution to Design Problem II 64

Problems 66

References 70

4 Diffusion and Mass Transfer 73

Design Problem III Design of a Dry-spinning System 73

4.1 Mass Transfer Fundamentals 74

4.1.1 Definitions of Concentrations and Velocities 74

4.1.2 Fluxes and Their Relationships 76

4.1.3 Fick's First Law of Diffusion 76

4.1.4 Microscopic Material Balance 78

4.1.5 Similarity with Heat Transfer: Simple Applications 80

4.2 Diffusivity! Solubility! and Permeability in Polymer Systems 84

4.2.1 Diffusivity and Solubility of Simple Gases 84

4.2.2 Permeability of Simple Gases and Permachor 87

4.2.3 Moisture Sorption and Diffusion 90

4.2.4 Permeation of Higher-Activity Permeants 90

4.2.5 PolymerPolymer Diffusion 93

4.2.6 Measurement Techniques and Their Mathematics 94

4.3 Non-Fickian Transport 95

4.4 Mass Transfer Coefficients 96

4.4.1 Definitions 96

4.4.2 Analogies Between Heat and Mass Transfer 97

4.5 Solution to Design Problem III 99

Problems 101

References 108

5 Nonisothermal Aspects of Polymer Processing 111

Design Problem IV Casting of Polypropylene Film 111

5.1 Temperature Effects on Rheological Properties 111

5.2 The Energy Equation 113

5.2.1 Shell Energy Balances 113

5.2.2 Equation of Thermal Energy 117

5.3 Thermal Transport Properties 120

5.3.1 Homogeneous Polymer Systems 120

5.3.2 Thermal Pro…