Extrusion of polymers : theory and practice / Chan I. Chung.

Format:

Book

Author/Creator:

Chung, Chan I.

Contributor:

Society of Plastics Engineers.

Class of 1932 Fund.

Series:

SPE books

Language:

English

Subjects (All):

Plastics--Extrusion.

Plastics.

Physical Description:

xiv, 369 pages : illustrations (some color) ; 25 cm.

Place of Publication:

Munich : Hanser Publishers ; Cincinnati : Hanser Gardner Publications, [2000]

Summary:

The author presents single-screw extrusion technology together with the relevant polymer fundamentals, with an emphasis on screw design. The presentation begins on a physical level providing an in-depth tutorial for conceptual understanding, followed by an analytical level with mathematical models. Practical applications of the mathematical models are illustrated by examples. A brief description of twin-screw extrusion technology is also presented.

Contents:

1.1 Polymer Processing 1

1.2 Polymer Extrusion 2

1.3 Types of Extruders 4

1.3.1 Single-Screw Extruders 4

1.3.2 Twin-Screw Extruders 7

2 Physical Description of Single-Screw Extrusion 11

2.1 Overall Functions of a Single-Screw Extruder 11

2.2 Feeding Function 17

2.3 Solid Conveying Function 18

2.3.1 Initial Forwarding and Compaction of Pellets 18

2.3.2 Solid Bed Conveying 20

2.4 Melting Function 23

2.4.1 Dissipative Melting 23

2.4.2 Conduction Melting 25

2.5 Metering Function 26

2.6 Melt Quality and Melt Stability 28

2.6.1 Definition of Melt Quality and Melt Stability 28

2.6.2 Melt Pressure 29

2.6.3 Melt Temperature 31

2.6.4 Mixing 32

2.6.5 Effective Residence Time and Residence Time Distribution 34

2.7 Thermodynamic Analysis of Polymer Extrusion 35

2.8 Cooling 39

2.8.1 Barrel Cooling 39

2.8.2 Screw Cooling 39

2.9 Motor Power-Drive Torque Relationship, Screw Torque Strength, and Types of Motors 40

2.9.1 Motor Power-Drive Torque Relationship 40

2.9.2 Screw Torque Strength 41

2.9.3 Types of Motors 42

2.10 Wear 43

2.11 Extruder Size and Instrumentation 44

2.11.1 Extruder Size 44

2.11.2 Instrumentation 45

2.12 Rubbing Mechanisms of Solid Polymer on Metal Surface 45

2.13 Relationships Between Screw Channel Geometries 47

2.14 Variables Controlling Polymer Extrusion 48

3 Fundamentals of Polymers 51

3.1 Introduction to Polymers 51

3.1.1 Polymer Molecules 51

3.1.2 Polymerization Reaction and Common Polymers 53

3.1.3 Classification of Polymers 56

3.2 Average Molecular Weights and Molecular Weight Distribution 59

3.2.1 Average Molecular Weights 59

3.2.2 Molecular Weight Distribution 61

3.2.3 Measurements of Average Molecular Weights 63

3.3 Molecular Structure and Morphology of Polymer Solid 73

3.3.1 Molecular Structure 73

3.3.2 Morphology of Polymer Solid 76

3.3.3 Glass Transition and Melting 87

3.3.4 Phase Separation in Blends, Block Copolymers, and Graft Copolymers 87

3.4 Effects of Processing Variables on Morphology 89

3.4.1 Stress and Strain 89

3.4.2 Temperature 91

3.4.3 Pressure 97

3.4.4 Annealing 98

3.5 Melt Rheology 98

3.5.1 Types of Fluids 99

3.5.2 Rheological Properties of Polymer Melts 104

3.5.3 Measurement of Melt Rheological Properties 118

3.5.4 Melt Flow Index 131

3.5.5 Extensional Flow and Tensile Viscosity 134

3.5.6 Flow Instability 135

3.5.7 Flow Through Simple Dies 141

3.5.8 Elastic Memory Effect on Extrudate Shape 148

3.5.9 Effects of Molecular Parameters on Melt Rheological and Physical Properties 149

3.5.10 Relationships between Melt Rheological Properties and Processability in Extrusion 153

3.6 Other Polymer Properties and Feed Characteristics Relevant to Extrusion 154

3.6.1 Thermodynamic Properties: Specific Heat, Enthalpy, and Heat of Fusion 154

3.6.2 Flow Temperature and Mechanical Melting 157

3.6.3 Thermo/mechanical Stability 158

3.6.4 External Friction and Internal Friction 158

3.6.5 Bulk Density and Compressibility of Feed 161

3.6.6 Melt Density 162

4 Theories of Single-Screw Extrusion 169

4.1 Three Basic Functions of a Single-Screw Extruder 169

4.2 Solid Conveying Models 170

4.2.1 Frictional Force and Viscous Shear Force 170

4.2.2 Output Rate in Terms of the Solid Conveying Angle 173

4.2.3 Analysis of the Solid Conveying Angle 177

4.2.4 Solid Conveying Model Based on Viscosity 181

4.2.5 Solid Conveying Model Based on Friction 193

4.3 Melting Models 201

4.3.1 Dissipative Melting Models 201

4.3.2 Conduction Melting Model 249

4.4 Metering Models 254

4.4.1 Isothermal Newtonian Fluid Model 256

4.4.2 Isothermal Power-Law Fluid Model 266

4.5 Effects of Flight Clearance 272

4.5.1 Solid Conveying Models 273

4.5.2 Melting Models 273

4.5.3 Metering Models 274

4.6 Comprehensive Extrusion Model 275

4.6.1 Computer Simulation 275

4.6.2 Output Rate 276

4.6.3 Motor Power 276

5 Screw Design, High Performance Screws, and Scale-Up 281

5.1 Screw Design 281

5.1.1 General Screw Design Guidelines 281

5.1.2 Scientific Screw Design Method 283

5.2 High Performance Screws 292

5.2.1 Flow Restriction/Mixing Type 295

5.2.2 Barrier-to-Melt Type 296

5.2.3 Barrier Between Solid Bed and Melt Pool Type 297

5.2.4 Solid/Melt Mixing Type 298

5.3 Motor Power as a Function of Screw Speed and Size 300

5.4 Melt Temperature as a Function of Screw Speed and Size 304

5.5 Scale-Up Methods 309

5.5.1 Common Scale-Up Method 310

5.5.2 Balanced Scale-Up Method Based on Melting Capacity 313

5.5.3 Scale-Up Method for Heat or Shear Sensitive Polymers 318

6 Gear Pump, Static Mixer, and Dynamic Mixer 321

6.1 Gear Pump 321

6.2 Static Mixer 323

6.3 Dynamic Mixer 324

7 Physical Description of Twin-Screw Extruders 329

7.2 Intermeshing Co-Rotating Twin-Screw Extruder 332

7.2.1 Conveying Elements 332

7.2.2 Kneading Blocks 334

7.2.3 Mixing Blocks 336

7.3 Intermeshing Counter-Rotating Twin-Screw Extruder 336

7.4 Non-Intermeshing Counter-Rotating Twin-Screw Extruder 338.

Notes:

Includes bibliographical references and indexes.

Local Notes:

Acquired for the Penn Libraries with assistance from the Class of 1932 Fund.

ISBN:

1569902887

3446213767

OCLC:

43701723