Fundamentals of Plastics Thermoforming

✍ Scribed by Peter Klein

• Publisher: Morgan and Claypool Publishers
• Year: 2009
• Tongue: English
• Leaves: 98
• Series: Synthesis Lectures on Materials Engineering
• Category: Library

✦ Synopsis

The process of heating and reshaping plastics sheet and film materials has been in use since the beginning of the plastics industry. This process is known as thermoforming. Today this process is used for industrial products including signage, housings, and hot tubs. It also produces much of the packaging in use today including blister packs, egg cartons, and food storage containers. This process has many advantages over other methods of producing these products, but it has some limitations. This book has a twofold purpose. It is designed to be used as a text book for a course on thermoforming. It is also intended to be an application guide for professionals in the field of thermoforming including manufacturing, process and quality engineers, and managers. This book is focused on process application rather than theory. It refers to real products and processes with the intent of understanding the real issues faced in this industry. In addition to materials and processes, part and tool design are covered. Quality control is critical to any operation and this is also covered in this text. Two areas of focus in today's industry include Lean operations and environmental issues. Both of these topics are also included. Table of Contents: Introduction / Plastics Materials / Thermoforming Process Overview / The Forming Process / Part Design Mold / Tool Design / Quality Control Issues / Lean Operations / Environmental Issues

✦ Table of Contents

SYNTHESIS LECTURES ON MATERIALS ENGINEERING......Page 4
Contents......Page 10
Advantages of Thermoforming......Page 16
Limitations/Disadvantages of Thermoforming......Page 19
Plastic Memory......Page 20
Molecular Structure......Page 23
Morphology......Page 24
Discovering Van der Waals' Forces......Page 26
Polystyrene (PS)......Page 27
Low Density Polyethylene (LDPE)......Page 28
Heat Deflection Temperature (HDT)......Page 29
Homopolymer......Page 30
Thermoforming Window......Page 31
Sheet Preparation......Page 32
Loading......Page 34
Heating......Page 35
Forming......Page 37
Cooling......Page 38
Trimming......Page 39
Mechanical Forming......Page 42
Pressure Forming......Page 44
Drape Forming......Page 45
Mechanical Preforming......Page 46
Laminating Thermoforming......Page 47
Design Questions......Page 50
Plug versus Cavity......Page 51
Draw Ratios......Page 55
Aerial Draw Ratio (ADR)......Page 56
Linear Draw Ratio (LDR)......Page 58
Material Selection......Page 59
Corners and Radii......Page 60
Draft Angles......Page 61
Depth of Draw......Page 62
Useful Temperature Range......Page 63
Stiffness......Page 64
Optics......Page 65
Dimensional Tolerances......Page 66
Mold Geometry / Shrinkage......Page 68
Venting......Page 70
Temperature Control......Page 71
Cavities......Page 72
Sheet Orientation......Page 76
Orientation Test......Page 77
Cosmetics......Page 79
Variation......Page 80
Quality Inspection......Page 81
Quality Tools......Page 82
Eliminating Waste......Page 86
Process Mapping......Page 87
Visual Controls......Page 88
Poka Yoke......Page 89
Recycling......Page 92
Material Selection......Page 93
Green Plastics......Page 94
About the Author......Page 98