The Principles Of Leather Manufacture

The origin of leather manufacture dates far back in the pre historic ages, and was probably one of the earliest arts practised by mankind. In the sketch of the development of leather manufacture, it has been implied that its object is to convert the putrescible animal skin into a material “which is permanent and not readily subject to decay, while retaining sufficient softness or flexibility for the purposes for which it is intended. Making leather is an extensive and technical process. In order for the process to produce high-quality leather with the same finish each time, accuracy and care must be taken. The book “The Principles of Leather Manufacture” provides extensive details about the vast topic to leather manufacturing. It deals with putrefaction, fermentation, curing of hides and skins structure and growth of skin. It also explores tawing iron, chrome tannages and dyeing. This book is a valuable compilation of various topics, ranging from the most basic to the most complex ones. It studies, analyses and upholds the pillars of this subject area and its utmost significance in modern times. For those who have an interest in leather, this book will prove to be a valuable source of knowledge.

Vince Will serves as an Adjunct Instructor at Institute of Art and Design, Edinburgh. He obtained his Post Graduation in Leather Design & Technology from University of Science and Technology, Lausanne. His teaching and research interests include leather manufacturing and production technology to operations management. Will has authored numerous articles and book chapters in the field of leather production management and flexible manufacturing systems. He has also been an invited speaker at various international conferences.

Preface IX
1. Introductory and Historical 1
1. Introduction 1
2. Production management 1
3. Primitive methods of leather manufacture 5
4. Use of leather by the ancients 7
5. Methods of production of leather 16
6. Vegetable tannages 20
7. Combination tanning 25
8. Oils & fats in the leather industry 31
9. Conclusion 33
References 33
MCQs 33
Answers 34
2. Introductory Sketch of Leather Manufacture 35
1. Introduction 35
2. The object of tanning 35
3. Leather and Suede 38
4. Removal of hair by liming 42
5. Unhairing by putrefaction 43
6. Deliming 51
7. Conclusion 52
References 52
MCQs 52
Answers 53
3. Putrefaction and Fermentation 54
1. Introduction 54
2. Fermentation 54
3. What is Putrefaction? 55
4. Classification of organised ferments 57
5. The alcoholic fermentation 64
6. Fermentation in bating and puering 66
7. Fermentation in tanning liquors 72
8. Conclusion 75
References 75
MCQs 76
Answers 76
4. The Origin and Curing of Hides and Skins 77
1. Introduction 77
2. Curing 78
3. Leather and Skin 79
4. Archaeological Leather 83
5. Chemical Deterioration 88
6. Conservation and care 89
7. Marking of hides 91
8. Fellmongering of sheep-skins 93
9. The use of salt 93
10. Drying of hides and skins 101
11. Conclusion 107
References 108
MCQs 108
Answers 108
5. Structure and Growth of Skin 109
1. Introduction 109
2. The Skin 109
3. Structure of calf- skin 115
4. Sources of Leather 117
5. Chemical Alterations Through Tanning 119
6. Leather Manufacture 120
7. The hair-sheath 124
8. Conclusion 126
References 126
MCQs 127
Answers 127
6. The Physical Chemistry of the Hide-Fibre 128
1. Introduction 128
2. Fibre Briefing: Leather 129
3. Raw Hide and Curing Process 131
4. The essentials of the tanning process 133
5. Preparation 139
6. Effect of salt 144
7. The pickling process 146
8. Conclusion 149
References 150
MCQs 150
Answers 150
7. Water as used in the Tannery 151
1. Introduction 151
2. Leather’s Water Footprint 151
3. Dyestuffs for Leather, Classses and Structures 154
4. Aspects of the Affinity of Dyestuffs to Leather 156
5. The Influence of Auxiliary Agents on Dye Affinity 159
6. Further Influences 162
7. Effect of hardness on plumbing 165
8. Washing of fresh hides 170
9. Danger of putrefaction 172
10. Soaking and softening of dry and dry-salted hides 174
11. Conclusion 179
References 179
MCQs 180
Answers 180
8. Alum Tannage or Tawing 181
1. Introduction 181
2. Nature of leather 182
3. Production processes 184
4. From other animals 187
5. Natural leather grain 191
6. Leather Grades and Leather Qualities 192
7. Types of Leather Grades – For Raw Hides 194
8. Types of Leather Cuts 195
9. Types of Leather from Different Animal Hides 197
10. Exotic Animal Leathers 198
11. Types of Leather Used for Furs 199
12. Finished Leathers 200
13. Conclusion 204
References 204
MCQs 205
Answers 205
9. Iron and Chrome Tannages 206
1. Introduction 206
2. Tanning Operation 207
3. Chrome tannages 212
4. Knapp's method of chrome tannage 219
5. Types of Tannage 222
6. Development of chrome tanning 225
7. Future of Chrome Tanning 227
8. Organic Tanning Options 233
9. Alternative Technologies 236
10. Conclusion 238
References 239
MCQs 239
Answers 240
10. Dyes and Dyeing 241
1. Introduction 241
2. Development of High Fastness Dyes 242
3. Leather Colour - Leather Colour - Leather Dye 243
4. Dyestuffs and Dyeing of Leather 249
5. Conclusion 259
References 260
MCQs 261
Answers 261
Index 263