About the Book
Practical guidance to sustainable packaging and its challenges with analysis of various packaging materials and their interactions with different environments
Degradation, Stabilization, and Recycling of Packaging Materials analyzes packaging materials and their interactions with different environments, discussing the degradation processes of different materials like plastics, wood, paper, glass, and metal, providing specific strategies to address these degradation processes, and exploring solid waste management, recent developments in recycling, and the principles of eco-friendly packaging design.
Organized into two parts, the first section of this book provides a comprehensive examination of how environmental factors such as heat, shear, light, air, packaged products, and stress affect packaging materials, focusing on the chemistry of their deterioration and stabilization methods. The second section explores solid waste management, recent developments in recycling, and key principles of eco-friendly packaging design, culminating in an extensive discussion of legal and regulatory aspects.
The book includes case studies and problem sets in each chapter, with solutions to the problems in an appendix in the back of the book.
Written by a team of highly qualified authors, Degradation, Stabilization, and Recycling of Packaging Materials includes discussion on:
Structure of tinplate and tin-free steel, corrosion in lacquered cans, and effects of producing, processing, and storing metals
Recyclable versus repulpable paper, uses of recycled papers, wet-strength papers, non-wood fibers as paper sources, and contamination issues with paper recycling
Plastic recycling rates, plastic scrap exports in the US and abroad, chemical versus mechanical plastic recycling, hydrocracking of plastics, and PE and PET recycling
Lightweight glass bottles, strategies to modify or strengthen glass, and the real recyclability of glass
Presenting advanced technical knowledge that demystifies the sustainable packaging landscape Degradation, Stabilization, and Recycling of Packaging Materials is a critical resource for researchers, students, and industry professionals in the field of materials science and packaging to evaluate challenges related to solid waste and devise effective disposal strategies.
Table of Contents:
Preface xiii
1 Introduction 1
1.1 General Introduction 2
1.2 What Are Some Ideal Properties of Packaging? 2
1.3 Liquid Resistance and Barrier Properties 3
1.4 End-of-Life (EoL) Outcomes 4
1.5 Life-Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) 4
1.6 Open-Looped Versus Closed-Loop Processes 5
1.7 Recycling 6
1.8 Biodegradable and Compostable Packaging 7
1.9 Concluding Remarks 7
References 8
2 Plastics 11
2.1 Introduction 11
2.2 How Are Polymers Named? 12
2.2.1 Classification of Polymers 12
2.2.1.1 Classification Based on the Polymer Structure 12
2.2.1.2 Classification Based on the Mechanism 13
2.2.1.3 Classification Based on the Source 13
2.2.1.4 Classification Based on Cost and Performance 14
2.2.1.5 Classification Based on Thermal Behavior 15
2.3 Molecular Architecture 15
2.3.1 Homopolymers and Copolymers 16
2.3.2 Polymer Molecular Weights 16
2.4 Polymer Characterization Techniques 19
2.4.1 Nuclear Magnetic Resonance Spectroscopy 20
2.4.2 Size Exclusion Chromatography 22
2.4.3 Viscosity 23
2.5 Microscopy Techniques 24
2.6 Physical State of a Polymer 24
2.7 Thermal Transitions 26
2.8 Mechanical Properties 27
2.9 Degradation of Polymers/Plastics 28
2.9.1 Overview 28
2.9.2 Impact of Degradation on Polymer Properties 29
2.10 Wanted Versus Unwanted Degradation in Polymers 29
2.10.1 Unwanted/Undesirable Degradation 29
2.10.2 Wanted/Desirable Degradation 30
2.11 Do all Polymers Degrade at the Same Rate? 31
2.11.1 How Can We Know if a Polymer Is Stable or not Against a Particular Degradation Environment? 31
2.12 Types of Polymer Degradation 32
2.12.1 Thermal Degradation 33
2.12.1.1 The Chemistry of Thermal Degradation 35
2.12.1.2 Some Polymers Degrade by Unzipping and Others by Random Scission 38
2.12.2 Oxidative Degradation 43
2.12.3 Photodegradation 51
2.12.4 Chemical Degradation 56
2.12.4.1 Hydrolysis 57
2.12.4.2 Environmental Stress Cracking 58
2.12.4.3 Other Chemical Reactions 59
2.12.4.4 Summary of Chemical Degradation Susceptibilities of Various Polymers 59
2.12.5 Mechanical Degradation 61
2.13 Methods for Studying Polymer Degradation 62
2.13.1 Weathering 63
2.13.2 Thermal Degradation 64
2.13.3 Photochemical Degradation 64
2.13.3.1 Change in Molecular Weight 64
2.14 Stabilization of Polymers 65
2.14.1 Antioxidants 65
2.14.1.1 Chain-breaking Electron Acceptors (CB-A Antioxidants) 66
2.14.1.2 Chain-breaking Electron Donors (CB-D Antioxidants) 68
2.14.2 Peroxide Decomposers 71
2.14.2.1 Stoichiometric Peroxide Decomposers (PD-S) 72
2.14.2.2 Catalytic Peroxide Decomposers (PD-C) 73
2.14.3 Metal Deactivators (MDs) 73
2.14.3.1 UV Light Absorbers and Other Light Stabilizers 74
2.14.3.2 UV Light Absorbers (UVA) 74
2.14.4 Quenchers of Photo-excited States 75
2.14.5 Special Stabilizers 77
2.14.6 Drawbacks of Stabilizers 78
2.15 Summary 82
Problem Set 82
References 83
3 Wood 87
3.1 Introduction 87
3.2 Wood Degradation 87
3.2.1 Weathering 88
3.2.1.1 Effects of Various Influences on Weathering 89
3.2.1.2 Effects of Wood Composition 89
3.3 Chemical Degradation 94
3.4 Biological Decomposition (Decay) 94
Problem Set 97
References 97
4 Paper Degradation and Stabilization 99
4.1 Introduction 99
4.2 Durability and Permanence 100
4.2.1 Quality of Paper Fiber 102
4.3 Biological Degradation of Paper 104
4.4 Wet-Strength Papers 104
4.4.1 Major Categories of Wet-Strength Papers 107
4.4.1.1 Urea-Formaldehyde B-stage Derivatives 107
4.4.1.2 Melamine-Formaldehyde Cationic Colloids and Derivatives 109
4.4.1.3 Polyamide-Polyamine-Epichlorohydrin (PPE) Resins 110
4.4.2 Overview of Wet-Strength Resins 110
4.5 Sustainable Materials for Paper Coating for Packaging Applications 112
4.6 Concluding Remarks 117
Problem Set for Chapter 4 117
References 118
5 Glass 121
5.1 Advantages of Glass 121
5.2 Disadvantages of Glass 122
5.3 Glass Chemistry 122
5.3.1 Composition 122
5.3.2 Glass Making Process 123
5.3.2.1 Common Types of Glass and Modification Strategies 124
5.3.2.2 Stability of Glass 125
5.4 Chemical Corrosion 126
5.4.1 Leaching 126
5.4.2 Etching 127
5.4.3 Weathering 127
5.5 Physical Stability and Strength of Glass 128
5.5.1 Strategies to Modify or Strengthen Glass 129
5.6 Chemical Modification and/or Strengthening 129
5.6.1 Strengthening via the Fused Salt Mixture Approach 130
5.6.2 Thermal Strengthening or Toughening 131
5.6.2.1 Recyclability of Glass 131
5.7 Conclusions 132
Problem Set 132
References 133
6 Degradation and Stabilization of Metals 135
6.1 Benefits of Metals as Packaging 135
6.2 Disadvantages of Metals as Packaging 136
6.3 Basic Aspects of Metal Corrosion 136
6.4 Elements Required for Corrosion 138
6.4.1 Anodes and Cathodes 138
6.4.2 Electrolyte (the Internal Circuit) 139
6.4.3 Circuit 140
6.5 Role of Liquid Water in Corrosion 140
6.6 Methods for Protecting Metals Used in Packaging from Corrosion 142
6.6.1 External Environment Protection 142
6.6.2 Internal Environment Protection 142
6.7 Structure of Tinplate and Tin-Free Steel 144
6.8 Corrosion in Plain (Uncoated) Tin Cans 146
6.8.1 Normal Detinning 148
6.8.2 Rapid Detinning 149
6.8.3 Partial Detinning and Pitting 149
6.8.4 Pitting Only 149
6.9 Corrosion in Lacquered Cans 149
6.10 Effects of Products, Processing, and Storage 152
6.10.1 Effects of Products 152
6.10.2 Effects of Processing and Storage Conditions 153
6.11 VCI Packaging Materials 155
6.12 Corrosion of Aluminum 157
6.13 Lacquer Coatings for Cans 159
6.13.1 Bisphenol A (BPA) 160
6.14 Concluding Remarks 162
Problem Set for Chapter 6 162
References 163
Further Reading 165
7 Solid Waste Issues 167
7.1 Overview of Packaging Waste in U.S. Municipal Solid Waste 167
7.1.1 Municipal Solid Waste 167
7.1.2 Products Generated in MSW, 2018 176
7.1.3 Materials Generated in MSW, 2018 176
7.2 Disposal of Packaging Materials 183
7.2.1 Landfills 183
7.2.2 Incineration 188
7.2.2.1 So, Which Is More Expensive, Landfilling or Incineration? 189
7.2.3 Heavy Metals in Packaging – CONEG Model Toxics Law 190
7.2.3.1 Heavy Metals 190
7.2.3.2 Lead 190
7.2.3.3 Cadmium 190
7.2.3.4 Mercury 190
7.2.3.5 Hexavalent Chromium 191
7.2.3.6 Heavy Metals in Packaging 191
7.3 Recovery 194
7.3.1 Composting 194
7.3.2 Composting Process 198
7.4 Reuse and Waste Reduction 201
7.4.1 Reuse 201
7.4.2 Source Reduction 203
7.5 Recycling 204
7.5.1 Recycling – General 204
7.5.2 Collection of Recyclables 206
7.6 Motivation 208
7.6.1 Convenience 210
7.6.2 Education/Publicity 212
7.6.3 Participation Rates Versus Diversion Rates 212
7.6.4 Separation/Sorting 213
7.7 MRFs 213
7.8 Comparative Advantages and Disadvantages 214
7.9 Concluding Remarks 215
Problem Set for Chapter 7 215
References 217
8 Recycling of Metal and Glass 225
8.1 Overview 225
8.2 Metal Recycling 226
8.2.1 Steel Recycling 226
8.3 Open-Loop and Closed-Loop Recycling 229
8.4 Steel Recycling Process 229
8.4.1 Steel Cans Recycling Process 229
8.5 Aluminum Recycling 230
8.5.1 Aluminum Beverage Cans 230
8.5.2 Other Aluminum Packaging 232
8.5.3 Aluminum Packaging Recycling Amounts 232
8.5.3.1 Aluminum Packaging Recycling Rates 232
8.5.4 Eddy Current Separation 233
8.6 Glass Recycling 235
8.6.1 Glass Recycling in the United States 235
8.6.2 Glass Packaging Recycling Amounts 235
8.6.3 Glass Recycling Elsewhere 236
8.6.4 Glass Recycling 237
8.6.5 Steps Involved in Glass Recycling 237
8.6.6 What is the Future of Glass? 239
8.7 Summary 242
Problem Set for Chapter 8 243
References 244
9 Paper and Paperboard Recycling 247
9.1 Sorting Phase 252
9.2 Processing Phase 252
9.3 Processing Phase: Pulp Screening and Cleaning 252
9.4 Processing Phase: Deinking 253
9.5 Processing Phase: Refining, Color Stripping, and Bleaching 253
9.6 Processing Phase: Papermaking 253
9.7 Recyclable Versus Repulpable Paper 254
9.8 Uses of Recycled Paper 255
9.8.1 Paper Recycling in Europe and Other Areas 257
9.9 Contamination Issues 259
9.10 Concluding Remarks 263
Problem Set for Paper Recycling 264
References 265
10 Plastics Recycling 269
10.1 Introduction 269
10.2 Plastic Recycling Rates 269
10.3 Recycling of Plastics Packaging 270
10.4 What Is the Impact of Impurities in Plastics Mechanical Recycling? 278
10.5 United States Plastic Scrap Exports 278
10.6 Plastic Recycling Elsewhere 280
10.6.1 European Plastic Recycling Numbers 280
10.7 Global Plastic Recycling Rates 281
10.8 CO2 Footprint of Different Ways of Plastic Disposal 282
10.9 Terminology in Plastic Recycling 282
10.9.1 Postindustrial Versus Postconsumer Plastics 282
10.9.2 Chemical Versus Mechanical Recycling 283
10.9.3 Extraction Approach 283
10.9.4 Pyrolysis 284
10.9.5 Chemical Upcycling 285
10.9.5.1 Challenges Associated with Plastics Recycling 285
10.9.5.2 Prices of Recycled plastics as of October 2023 285
10.10 Emerging Trends in Recycling 286
10.10.1 Challenges in Mechanical Recycling of Plastics 286
10.10.1.1 Path Forward to Solve this Problem 286
10.10.2 Digital Watermarking 286
10.10.3 Near IR sorting 287
10.10.4 Monomaterials 288
10.10.5 Moving Towards Fewer Plastics 288
10.10.6 Additives for Mechanical Recycling 288
10.10.7 Additives to Enhance Properties of Recycled Materials 289
10.10.8 Flexible packaging 289
10.10.9 Path Forward in Mechanical Recycling 289
10.11 Trends in Chemical Recycling 289
10.11.1 Depolymerization to Monomers 290
10.11.2 Conversion of Plastic Waste into Petrochemicals (chemicals) 290
10.11.3 Summary of the Plastic Recycling Landscape 292
10.11.4 PET Recycling 292
10.11.5 Chemical Recycling of PET 293
10.11.6 Key Technologies/initiatives in PET (Polyesters) Chemical Recycling 295
10.11.7 Challenges PET Chemical Recycling 295
10.11.8 Polyurethanes 296
10.11.9 Polystyrene 296
10.11.10 Recycling of PE (HDPE, LDPE, LLDPE) 297
10.11.11 Chemical Recycling of PE 298
10.11.11.1 Catalytic pyrolysis 298
10.11.12 Hydrocracking of Plastics 300
10.11.12.1 Ongoing Research 301
10.11.13 Polypropylene 301
10.11.14 Gasification of Mixed Plastics to Syngas 301
10.11.15 Use of Recycled Plastics in Food Packaging 302
10.12 Concluding Remarks 309
Problem Set for Chapter 10 309
References 312
11 Legal, Regulatory, EPR, and Green Design 321
11.1 Introduction 321
11.2 EU Packaging Directives 322
11.2.1 EU Directive Amendment (2018/852) 323
11.2.2 How Are the Recycling Rates Calculated? 324
11.3 Extended Producer Responsibility (EPR) 325
11.3.1 Historical Background of EPR 326
11.3.2 What Are the Potential Benefits of EPR? 327
11.3.3 Recycled Content 328
11.3.3.1 Oregon 328
11.3.3.2 California 329
11.3.4 Plastic Bags 330
11.3.5 Single-Use Plastics 330
11.4 Green Design 331
11.4.1 Problematic Materials and Their Alternatives 331
11.4.1.1 U.S. Plastics Pact 332
11.4.1.2 Three Key Targets of the U.S. Plastics Pact 332
11.4.1.3 The Do’s of Recyclable and Compostable Packaging 332
11.5 The Path Forward for Packaging Sustainability 332
11.5.1 Emerging Packaging Trends and Technology 332
11.6 Concluding Remarks 336
Problem Set for Chapter 11 336
References 337
Further Reading 342
Appendix 1: Solutions to Problem Sets 343
Index 357
About the Author :
Muhammad Rabnawaz, PhD is an Associate Professor for the Michigan State University (MSU) School of Packaging.
Susan E. M. Selke, PhD is Professor Emeritus in the Michigan State University (MSU) School of Packaging.
Ian Wyman, PhD is a Professional Aide in the Michigan State University (MSU) School of Packaging.
