Bottles, preforms and closures : a design guide for PET packaging

As a consultant to the plastics industry, Ottmar Brandau's focus is on using his engineering knowhow and production management experience to improve quality and productivity, cut down cycle time and introduce secondary processes such as inline printing. This book is a thoroughly practical handbook that provides engineers and managers with the toolkit to improve production and engineering aspects in their own businesses - saving money, increasing output and improving competitiveness by adopting new technologies.

In this book, Brandau covers the engineering aspects of bottle production and the relevant production processes (focusing on blow molding), along with plant layout and organization and production management, to produce the definitive handbook for engineers and managers alike.

Author Notes

Ottmar Brandau has been working in the plastics industry since 1978, and is the founder of OB Plastics Consulting (now APEX Container Tech Inc). He has trained machine operators and engineers all over the world, and has comprehensive experience in all aspects of stretch blow molding and injection molding of preforms. 1 Os web site is: www.blowmolding.org.

Acknowledgments	p. vi
Editor's Note	p. xi
Foreword to the Second Edition	p. xiii
1 PET Beverage Bottles	p. 1
1.1 From the First Idea to the Finished Bottle	p. 2
1.1.1 Development Over the Past 25-30 Years	p. 2
1.1.2 Starting Point of a Product Development	p. 4
1.1.3 Design Engineering	p. 12
1.2 Determination of Bottle Properties	p. 13
1.2.1 Top Load	p. 13
1.2.2 Internal Pressure	p. 14
1.2.3 Handling Stability	p. 14
1.2.4 Stress Cracking	p. 14
1.2.5 Barrier	p. 15
1.3 Generating the First Design in CAD	p. 17
1.3.1 The Bottle Design Already Exists	p. 17
1.3.2 Creation of a New Design	p. 18
1.4 From Shape to Full-Fledged Design for a Dependable Process	p. 22
1.4.1 From the Ideal to the Real Preform	p. 22
1.4.2 Bottle Design for a Dependable Process	p. 24
1.5 Verification of the 3D Design Through Finite-element Simulation	p. 26
1.5.1 What is FEM?	p. 26
1.5.2 What FEM Can Do	p. 27
1.5.3 What FEM Cannot Do	p. 28
1.6 Selection of the Mold Concept to Meet Customer-specific Criteria	p. 28
1.6.1 Shell Molds	p. 29
1.6.2 Hot-fill Molds	p. 29
1.7 Mold Design and Mold Manufacture	p. 30
1.7.1 Mold Design	p. 30
1.7.2 Mold Making	p. 34
1.8 Mold Trials and Examination of Sample Bottles	p. 35
1.8.1 Mold Trials on Laboratory Machines	p. 35
1.8.2 Process Finding During Mold Trials	p. 37
1.8.3 Laboratory Tests on Sample Bottles	p. 38
2 PET Preforms	p. 47
2.1 Introduction	p. 47
2.2 Manufacture and States of PET	p. 50
2.2.1 Manufacture of PET	p. 50
2.2.2 Catalysts	p. 51
2.2.3 PET is a Linear Condensation Polymer	p. 51
2.2.4 Crystallization of PET	p. 53
2.2.5 "Extended Chain" or "Oriented" Crystallization	p. 55
2.2.6 Summary	p. 55
2.3 Behavior in the Blow Mold 56 2.3.1 Natural stretch Ratio (or Natural Draw Ratio)	p. 56
2.4 Manufacture of PET Preforms	p. 60
2.4.1 Drying of PET	p. 60
2.4.2 The Theory of Injection Molding of Preforms	p. 62
2.5 Preforms for Single- and Two-stage Processing	p. 65
2.5.1 Two-stage Process Injection Molding	p. 65
2.5.2 Two-stage Process Blow Molding	p. 66
2.5.3 Single-stage Process	p. 66
2.5.4 Hot Runner Controls	p. 73
2.5.5 Gate Mechanism	p. 73
2.6 PET and Infrared Radiation	p. 75
3 Practical Guide to Injection Molding of Preforms	p. 79
3.1 Extrusion and Screw Control	p. 80
3.2 Injection Parameters	p. 86
3.2.1 Injection Pressure	p. 86
3.2.2 Injection Speed and Time	p. 87
3.2.3 Transition Point	p. 89
3.2.4 Hold Time and Pressure	p. 91
3.2.5 Decompression	p. 92
3.2.6 Cooling Time	p. 93
3.2.7 Gating	p. 93
3.2.8 Postmold Cooling Devices	p. 95
3.2.9 Machine Cycle Improvements	p. 96
3.3 Optimizing the Injection Settings	p. 97
3.4 Cycle Time Calculations	p. 99
3.5 Challenges in Thin-wall Molding	p. 99
3.6 Acetaldehyde in PET Bottles	p. 101
3.6.1 AA Creation	p. 101
3.6.2 AA in Water Bottles	p. 103
3.6.3 AA-level Measurements	p. 104
3.7 Injection Tooling	p. 105
3.8 Cooling Issues	p. 108
3.8.1 Antifreeze	p. 110
3.8.2 Water Flow Balance	p. 111
3.9 Tool Wear Issues	p. 112
4 Closures for PET Bottles	p. 115
4.1 Introduction	p. 116
4.1.1 Closure History	p. 117
4.1.2 Closure Functions	p. 118
4.2 Different Neck Finishes for Various Applications	p. 119
4.2.1 Neck Finishes for CSD Bottles	p. 119
4.2.2 Neck Finishes for Still Water Bottles	p. 120
4.2.3 Neck Finishes for Hot-filled Products	p. 122
4.2.4 Necks for Custom Bottles	p. 124
4.3 Closure Types	p. 125
4.3.1 One-piece Closures	p. 125
4.3.2 Two-piece Closures	p. 127
4.3.3 Sports Closures	p. 130
4.3.4 Closures and Shelf Life	p. 131
4.3.5 Multilayer Liners	p. 133
4.4 Tamper-evident Bands	p. 134
4.4.1 Construction Methods	p. 135
4.4.2 Pilfer-proof Rings and Their Construction	p. 137
4.5 Resins	p. 139
4.5.1 Polypropylene	p. 139
4.5.2 High-density Polyethylene	p. 142
4.6 Manufacturing Methods	p. 143
4.6.1 Injection Molding	p. 143
4.6.2 Compression Molding	p. 145
4.6.3 Comparison of TM-CM	p. 147
4.7 Economic Guidelines	p. 148
4.8 Test Procedures	p. 150
4.8.1 Proper Application Test	p. 150
4.8.2 Top-load Vent Test	p. 151
4.8.3 Cold Removal Torque Test	p. 151
4.8.4 Ambient Removal Torque Test	p. 151
4.8.5 Cycle Test at Elevated Temperature	p. 151
4.8.6 Vent/Flow Performance Test	p. 151
4.8.7 Strip Torque Test	p. 152
4.8.8 Carbonation Retention Non-top Load	p. 152
4.8.9 Carbonation Retention at Elevated Temperature	p. 152
4.8.10 Carbonation Retention with Top Load	p. 152
4.8.11 Plastic Ball Impact Test	p. 152
4.8.12 Drop Test	p. 153
4.9 General IM Process Parameters for CSD Closures	p. 153
4.9.1 Injection Time	p. 154
4.9.2 Hold Time	p. 155
4.9.3 Cooling Time	p. 155
4.9.4 Mold Closing and Opening Times	p. 156
4.9.5 Ejection Time and Mold Opening Stroke	p. 156
4.9.6 Plasticizing	p. 156
4.9.7 Delay Times	p. 157
4.9.8 Air Blast	p. 157
4.10 Lightweigbing of Bottles and Caps	p. 157
4.10.1 Lighter Necks	p. 158
4.10.2 Lighter Caps	p. 159
Appendix A Specific Resins for Closure Production	p. 162
Index	p. 165

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Table of Contents