Extrusion in Ceramics

von: Frank Händle

Springer-Verlag, 2007

ISBN: 9783540271024 , 413 Seiten

Format: PDF, OL

Kopierschutz: Wasserzeichen

Windows PC,Mac OSX Apple iPad, Android Tablet PC's Online-Lesen für: Windows PC,Mac OSX,Linux

Preis: 154,69 EUR

Mehr zum Inhalt

Extrusion in Ceramics


 

Contents

6

List of Contributors

8

Acknowledgements

10

Introduction

11

1.1 What to Expect

11

1.2 History of an Obsession

12

1.3 About the Various Contributions

15

1.4 Famous LastWords

18

References

21

Shaping in Ceramic Technology – An Overview

23

2.1 Dry Pressing

24

2.2 Extruding

31

2.3 Slip Casting

33

References

40

Current Classification of Ceramic Materials

44

3.1 Classification by Application or Chemical-Mineralogical Structure

44

References

65

Types of Extrusion Units

67

4.1 Classification by the Range of Application

68

4.2 Classification by the Product to be Extruded

70

4.3 Classification by the Arrangement of the Auger Shaft and Direction of Column Exit

70

4.4 Classification by the Diameter of the Extruder Barrel

73

4.5 Classification by the Number of Auger Shafts

74

4.6 Classification by the Consistency of the Body to be Processed

76

4.7 Classification by the Design of the Extruder Barrel

77

4.8 Classification by the Design and Mounting of the Augers

80

4.9 Classification by Specific Extrusion Method

81

4.10 Classification by the Type of De-Airing Device Employed

85

4.11 Classification by the Extruder Design Features

85

4.12 Classification by the Design of the De-Airing Mixer

89

4.13 Classification by the Design Version of the Combined De- Airing Extrusion Unit

89

References

92

A Short History of the Extruder in Ceramics

93

5.1 The Development of the Extruder and Column Shaping

94

5.2 The Development of Individual Extruder Components

109

5.3 The Development of the Vacuum Extruder and Combined De- Airing Extrusion Unit

126

5.4 The Extruder in the Different Fields of Ceramics

129

5.5 Chronology of Extrusion in Ceramics

132

References

135

The Principle of the Auger Extruder

137

6.1 Introduction

137

6.2 Liquid Phase and Additives

137

6.3 Physics of Process Steps

138

6.4 Engineering Implementation

142

6.5 Other Types of Product

144

6.6 Range of Product Size and Shape

146

6.7 Other Technologies

146

6.8 Final View

147

References

148

Rheology of Ceramic Bodies

149

7.1 Introduction

149

7.2 The Material Law

149

7.3 Dynamic Consideration of Cylindrical-Tube Pressure Flow of Bingham Media with Wall Slippage

156

7.4 True Flow Curve

158

7.5 The Rheological Simulation Model

161

7.6 Summary and Prospects

165

References

167

Rheology and Extrudability of Ceramic Compounds

168

8.1 Introduction

168

8.2 Rheological Test Methods for Describing Extrudability

170

8.3 Summary

178

References

178

Scenarios of Extrusion

179

9.1 Introduction

179

9.2 Functioning of Screw Extruders

179

9.3 Measures

186

9.4 Conclusion

191

References

192

Laminations in Extrusion

193

10.1 Definition

193

10.2 Causes of the Development of Laminations and Different Types of Laminations

194

10.3 De-Airing Laminations

205

10.4 Laminations as a Result of Inhomogeneous Body

207

10.5 Methods for Detection and Evaluation of Laminations

207

10.6 Opportunities for Minimising Detrimental Effects Caused by Laminations

211

10.7 Conclusion

214

References

215

Additives for Extrusion

217

11.1 Introduction

217

11.2 Additive Types

220

11.3 The Chemical Structure and Mechanism of Action of Plasticizing Additives

222

11.4 Summary

225

References

226

Dies, Pressure Heads, Strainer Plates and More

227

12.1 Outline/Introduction

227

12.2 Specific Characteristics of Ceramic Extrusion Body with Regard to Shaping

228

12.3 Factors of Influence to be Considered for the Design of Extrusion Tools

228

12.4 Combination Pressure Head and Die Assemblies for Technical Ceramics

229

12.5 Combination Pressure Head and Die Assemblies in Heavy Clay Ceramics

233

Conclusions

237

12.6 Brief Overview of Tribomaterials Customarily Employed in Ceramic Extrusion Tools

244

12.7 Closing Remarks

245

References

245

Twin-Screw Extruders in Ceramic Extrusion

246

13.1 Introduction

246

13.2 History of Batch and Continuous Kneading

246

13.3 Working Principle of Co-Rotating Twin-Screw Extruders

249

13.4 High-Torque Versus High-Volume Extruders

251

13.5 Compounding Applications with High Solid Contents

254

13.6 Ceramic Extrusion Plants

255

13.7 Summary

262

References

263

Piston Extruders

264

14.1 Piston Extruders in Ceramics

264

14.2 Types of Piston Extruder

264

14.3 The Components of Piston Extruders

265

14.4 The Pros and Cons of Piston Extruders

275

14.5 Auxiliary Equipment

275

14.6 Development

277

14.7 Literature

278

Evacuation in Ceramic Extrusion – Dependences and Local Situations

279

15.1 Vacuum Measurement

280

15.2 Percent Vacuum as a Function of Site Elevation, Parameter: Temperature of Extrusion Compound

281

15.3 Percent Vacuum as a Function of Weather-Induced Differences in Air Pressure Parameter: Temperature of Extrusion Compound

282

15.4 Physical Interdependences

282

References

283

Evacuation Technology for Ceramic Extrusion

284

16.1 Introduction

284

16.2 Liquid-Ring Vacuum Systems

284

16.3 Vacuum Systems with Rotary Vane Vacuum Pumps

287

16.4 Vacuum Systems with Dry-Running Vacuum Pumps

289

16.5 Vacuum Pump Combinations

291

16.6 Components of the Vacuum System

293

16.7 Control and Regulation

296

16.8 Summary

296

References

297

Thermoplastic Extrusion for Ceramic Bodies

298

17.1 Introduction

298

17.2 Thermoplastic Extrusion Processing

300

17.3 Thermoplastic Extrusion Processing

304

17.4 Conclusion

313

References

313

Tribological Principles

315

18.1 Tribological System

315

18.2 ElementaryWear Processes

318

References

322

Measures for Protection Against Abrasion on Screws Used in Extruding Ceramic Compounds

323

19.1 Protection Against Abrasion by Using the Appropriate Material

323

19.2 Layer-Based Abrasion Protection

325

References

331

Perspectives forWear Reduction with Ceramic Extruder Components

332

20.1 Introduction

332

20.2 Properties of Ceramics

332

20.3 Design and Field Testing of Ceramic Augers

337

20.4 Application of a Ceramic Auger in the Production Process for Al2O3 Filtration Tubes

343

20.5 Conclusions and Outlook

346

References

346

Test Methods for Plasticity and Extrusion Behaviour

348

21.1 Actuating Variables

348

21.2 Test Methods to Determine Plasticity

355

References

362

Simulation in Ceramic Extrusion

364

22.1 The Fundamentals

364

22.2 Solution of the Governing Equations

372

22.3 Computational Fluid Dynamics for Ceramic Extrusion

374

References

379

Selected Literature

380

The Authors of the Book

396

Index

410