International Plastics Handbook
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Tim A. Osswald, Erwin Baur, Sigrid Brinkmann
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International Plastics Handbook
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Carl Hanser Fachbuchverlag
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9783446407923
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4
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CHF 71.10
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Naturwissenschaft
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English
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921
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Wasserzeichen/DRM
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PC/MAC/eReader/Tablet
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PDF
PREF CE
As the title suggests, this handbookwaswritten as a source of reliable information for the practicing engineer, in a world which is increasingly driven by globalization. While it was written for the American market, the book also includes international standards and information that is now often necessary for any practicing engineer. Plastics remains the material group with the largest growth rate worldwide. This is due to their unique characteristics; the ease of production of complex parts with relatively economical processes, and the ability to tailor the properties of the material to suit a specific application. Due to these attributes, today we find that plastics are not only replacing traditionalmaterials, but are the driving force in innovation in the fields of electronic products,medicine, automobiles, household goods, and construction. Thus, we find uncountable examples of how plastics have improved our standard of living in the last decade alone; from lighter automobiles to thinner cellular telephones, and from more fuel ef- ficient composite aircraft to improved human heart valves, all made possible by advances in plastics and plastics technology. The plastics industry will continue to grow and develop, as the properties of polymers achieve higher limits, continuously replacing other materials and making new applications and products possible. The image of plastics has seen a positive turn in the last decade. Many studies have shown that plastics are the driving force in the solution of ecological problems; from making vehiclesmore fuel efficient, to allowing themanufacture of complex products with a fraction of the energy required when using metals. Furthermore, today we find ourselves revisiting the past, where plastics were made of renewable resources.
At the end, it is really only a question of economics, whether we will make plastics from petroleum or from bio-materials. From this point of view, we can really say that the age of plastics is still in its infancy. International Plastics Handbook is based on a similar publication, which has been available to the German plastics engineer for the past 70 years. A new edition of the German book Saechtling Kunststoff Taschenbuch, now in its 29th edition, appears every three years at the K-Show, in Duesseldorf, Germany. In 1936, when the first edition of the German book was published, Dr. F. Pabst, the original author of the German handbook, wrote"This book is intended to answer questions in the applied field of plastics." For this handbook, that is our intent as well. This first edition of International Plastics Handbook will appear at the NPE show in Chicago, in June of 2006. Due to the rapid changes in the field of plastics we are planning to present new editions of the handbook at NPE shows, every three years. In addition, this book will be accessible through the World- WideWeb where the authors will maintain updated versions of the handbook, including its tables and list of trade names.
Each handbook contains an individual code on the inside front cover which provides access for the download of the electronic version of the book at www.hanser.de/plasticshandboo . The authors cannot possibly acknowledge everyone who in oneway or another helped in the preparation of this handbook. First of all wewould like to thank Drs. Wolfgang Glenz and Christine Strohm of Hanser publishers for being the catalysts for this project. Additionally, Dr. Strohm gave us her input and support during the years it took to prepare this handbook. Chapter 6 comes from the German Saechtling Kunststoff Taschenbuch materials chapter, which was translated by Dr. Strohm. We are indebted to her for all of this. Special thanks are due to Luz Mayed D. Nouguez for the superb job of drawing the figures. We are grateful to Sylvana Garc´ýa and Alejandro Rold´an for the long hours they put into generating tables for the book and preparing the camera-ready manuscript. We thank Juan Pablo Hern´andez-Ortiz for developing the typesetting template. We also thank Oswald Immel for his support throughout the development of the manuscript. Above all, we thank our families for their patience, encouragement and support.
TIM A. OSSWALD Madison, Wisconsin Spring, 2006
CHAPTER 4
PLASTICS PROCESSES
(p. 271-272)
Manufacturing of plastic parts can involve one or several of the following steps:
• Shaping operations - This involves transforming a polymer pellet, powder or resin into a final product or into a preform using extrusion or molding processes such as injection, compression molding or roto molding.
• Secondary shaping operation - Here a preform such as a parison or sheet is transformed into a final product using thermoforming or blow molding.
• Material removal - This type of operation involvesmaterial removal using machining operations, stamping, laser, drilling, etc.
• Joining operations - Here, two or more parts are assembled physically or by bonding or welding operations.
Most plastic parts are manufactured using shaping operations. Here, thematerial is deformed into its final shape at temperatures between room temperature and 350oC, using wear resistant tools, dies and molds. For example, an injection mold would allow making between 106 and 107 parts without much wear of the tool, allowing for the high cost of themolds utilized. One of themany advantages of polymer molding processes is the accuracy, sometimes with features down to the micrometer scale, with which one can shape the finished product without the need of trimming or material removal operations. For example, when making compact discs by an injection-compression molding process, it is possible to accurately produce features, that contain digital information smaller than 1µm, on a disc with a thickness of less than 1mmand a diameter of several centimeters.
The cycle time to produce such a part can be less than 3 seconds. In the past fewyears, we have seen trendswheremore complex manufacturing systems are developed that manufacture parts which use various materials and components such as co-extrusion ofmultilayer films and sheets,multi-component injection molding, sandwiched parts, or hollow products. Thermoplastics and thermoplastic elastomers are shaped and formed by heating them above glass transition or melting temperatures and then freezing them into their final shape by lowering the temperature. At that point, the crystallization, molecular or fiber orientation and residual stress distributions are an integral the finished product.
Similarly, thermosetting polymers and vulcanizing elastomers solidify by a chemical reaction that results in a cross-linked molecular structure. Here too, the filler or fiber orientation as well as the residual stresses are frozen into the finished structure after cross-linking. This chapter is intended to give an introduction to the most important polymer processes.
4.1 RAW MATERIAL PREPARATION
Raw material preparation is understood as the necessary steps taken before the polymeric material is processed into the finished product. Such steps include the addition of components or additives such as pigments, fillers, fibers, platicizers, lubricants, stabilizers, flame retardants, foaming agents, solvents, or other polymers, or the material’s transformation into a powder, paste or pellet. The most important material preparation operations are mixing, kneading, disolving, granulating or pelletizing, and drying.
4.1.1 Mixing Processes
Today, most processes involve some form of mixing. For example, an integral part of a screw extruder is a mixing zone. In fact, most twin screw extruders are primarily used as mixing devices. Similarly, the plasticating unit of an injection molding machine often has a mixing zone. This is important because the quality of the finished product in almost all polymer processes depends in part on how well the material was mixed. Both the material properties and the formability of the compound into shaped parts are highly influenced by the mixing quality. Hence, a better understanding of themixing process helps to optimize processing conditions and increase part quality.
The process of polymer blending or mixing is accomplished by distributing or dispersing aminor or secondary componentwithin amajor component serving as a matrix. The major component can be thought of as the continuous phase, and the minor components as distributed or dispersed phases in the form of droplets, filaments, or agglomerates. When creating a polymer blend, one must always keep in mind that the blend will probably be remelted in subsequent processing or shaping processes. For example, a rapidly cooled system, frozen as a homogenous mixture, can separate into phases because of coalescence when re-heated. For all practical purposes, such a blend is not processable.
Preface
8
Contents
10
Chapter 1 Introduction
20
1.1 STATISTICAL DATA
20
1.2 POLYMER AND PLASTICS CATEGORIES
24
1.3 PLASTICS ACRONYMS
27
Chapter 2 Materials Science of Polymers
36
2.1 POLYMER STRUCTURE
36
2.1.1 Chemistry
36
2.1.2 Morphological Structure
54
2.1.3 Thermal Transitions
58
2.2 MATERIAL MODIFICATION OF PLASTICS
72
2.2.1 Polymer Blends
72
2.2.2 Filled Polymers and Reinforced Composites
73
2.2.3 Other Modifications
76
2.3 PLASTICS RECYCLING
77
Chapter 3 Properties and Testing
82
3.1 COMPARABILITY OF MATERIAL PROPERTIES
82
3.2 THERMAL PROPERTIES
86
3.2.1 Thermal Conductivity
86
3.2.2 Specific Heat and Specific Enthalpy
93
3.2.3 Density
95
3.2.4 Thermal Diffusivity
101
3.2.5 Linear Coefficient of Thermal Expansion
101
3.2.6 Thermal Penetration
110
3.2.7 Thermal Data Measuring Devices
111
3.3 CURING BEHAVIOR
118
3.4 RHEOLOGICAL PROPERTIES
122
3.4.1 Flow Phenomena
122
3.4.2 Viscous Flow Models
128
3.4.3 Rheometry
134
3.4.4 Surface Tension
141
3.5 MECHANICAL PROPERTIES
145
3.5.1 The Short-Term Tensile Test
145
3.5.2 Impact Strength
160
3.5.3 Creep Behavior
179
3.5.4 Dynamic Mechanical Tests
191
3.5.5 Fatigue Tests
197
3.5.6 Strength Stability Under Heat
204
3.6 PERMEABILITY PROPERTIES
213
3.6.1 Sorption
214
3.6.2 Diffusion and Permeation
214
3.6.3 Measuring S,D, and P
220
3.6.4 Diffusion of Polymer Molecules and Self-Diffusion
222
3.7 FRICTION AND WEAR
224
3.8 ENVIRONMENTAL EFFECTS
226
3.8.1 Water Absorption
227
3.8.2 Weathering
230
3.8.3 Chemical Degradation
233
3.8.4 Thermal Degradation of Polymers
235
3.9 ELECTRICAL PROPERTIES
242
3.9.1 Dielectric Behavior
242
3.9.2 Electric Conductivity
248
3.9.3 Application Problems
254
3.9.4 Magnetic Properties
266
3.10 OPTICAL PROPERTIES
268
3.10.1 Index of Refraction
269
3.10.2 Photoelasticity and Birefringence
270
3.10.3 Transparency, Reflection, Absorption and Transmittance
276
3.10.4 Gloss
278
3.10.5 Color
281
3.10.6 Infrared Spectroscopy
282
3.11 ACOUSTIC PROPERTIES
285
3.11.1 Speed of Sound
285
3.11.2 Sound Reflection
285
3.11.3 Sound Absorption
287
Chapter 4 Plastics Processes
290
4.1 RAW MATERIAL PREPARATION
291
4.1.1 Mixing Processes
291
4.2 MIXING DEVICES
294
4.2.1 Mixing of Particulate Solids
294
4.2.2 Screw-Type Mixers
294
4.2.3 Granulators and Pelletizers
307
4.2.4 Dryers
309
4.3 EXTRUSION
313
4.3.1 The Plasticating Extruder
315
4.3.2 Troubleshooting Extrusion
323
4