Thermoforming: A Plastics Processing Guide, Second Edition

✍ Scribed by George Gruenwald

• Publisher: CRC Press;Routledge
• Year: 2017
• Tongue: English
• Leaves: 256
• Edition: 2nd ed
• Category: Library

✦ Synopsis

FROM THE FOREWORD

Dr. Gruenwald has indicated the desirable properties of polymerics for differing applications; thus, his text is especially useful for polymer chemists who must ''tailor'' plastic materials for specific groups of applications. Engineers in extruding and calendering film and sheet will benefit from the intimate relationships elucidated between processing parameters imposed upon stocks employed in thermoforming and the products thereof. Mold designers are provided with a complete guide that will enable them to avoid the less obvious pitfalls and wasted effort so often experienced in the evolution of molds for (especially) complex parts.. Quite likely, Dr. Gruenwald's suggestions willl lead to considerable benefits to those who read and practice by this remarkable exposition of thermoforming technology.

Robert K. Jordan
Director-Metalliding Institute, Director-Engineering Research Institute, Scientist in Residence, Gannon University

✦ Table of Contents

Content: Cover
Half Title
Title Page
Copyright Page
Table of Contents
Foreword
Preface
1: Introduction
2: Heating of the Plastic
Means of conveying heat to the plastic
Physics of radiation heating
Thermal properties of plastics
Heating equipment for plastic sheets
Judging the correct temperature of the heated sheet
Heater controls
Clamping of sheets
3: Thermoforming Molds
Reduction in wall thickness: male and female molds
Computer-aided engineering for thermoforming
Part shrinkage and dimensional tolerances
Warpage
Draft in the mold
Surface appearance
Mold materials Mold-cooling provisionsAir passage holes
Increasing stiffness
Mold plugs
4: Vacuum, Air Pressure, and Mechanical Forces
Measuring vacuum and pressure forces
Vacuum sources
Vacuum accumulators or surge tanks
Application of vacuum forces
Pressure forming
Mechanical forming
5: Cooling of Thermoformed Parts
Means o f cooling the formed part
Non-conventional cooling methods
6: Trimming of Thermoformed Parts
Tools for trimming
7: Thermoforming Equipment
Single-station thermoformer
Shuttle thermoformer
Rotary thermoforming equipment
Continuous in-line thermoformers In-line thermoformerLinear thermoformers
Pneumatic thermoformers
Hydraulically operated thermoformers
Mechanically operated thermoformers
Skin packaging equipment
Blister packaging equipment
Snap packaging
Vacuum packaging
Packaging machinery
Control mechanisms
8: Thermoforming-Related Material Properties
Glass transition temperature
Heat deflection temperature
Softening range and hot strength
Specific heat
Thermal conductivity
Thermal expansion
Heat of fusion
Thermal diftusivity
Thermal stability
Water absorption
Orientation and crystallization Manufacture o f starting materialsCoextrusions and laminates
Mechanical properties
Material economics
Regrind utilization
9: Thermoforming Materials' Chemical Descriptions
Acrylics
Cellulosics
Polyolefins
Styrene polymers
Vinyl resins
Engineering plastics
Copolymers, blends, and alloys
Fiber-reinforced thermoplastics
Transparent materials
Barrier materials
Electrical properties
Plastics recycling
Flammability of plastics
Toxicity of plastics
10: Thermoforming Processes
Billow, bubble, or free forming
Cavity forming
Drape forming
Plug-assist forming
Billow drape forming Snap-back formingAir slip forming
Reverse draw with plug-assist forming
Trapped sheet pressure forming
Twin-sheet forming
Pressure forming
Mechanical thermoforming
Plug-and-ring forming or ridge forming
Slip forming
Matched-mold forming
Rubber pad and fluid pressure or diaphragm forming
Other thermoforming processes
Adjusting process parameters
Thermoforming troubleshooting guide
11: Design Considerations
Assembly and bonding
Snap-fits
Mechanical bonding
Forming around inserts
Welding
Solvent bonding
Adhesive bonding
Rigidizing thcrmoformed parts
Bonding multiple parts