Page 17 - Plastics Engineering

xvi Preface to the First Edition

This book is intended primarily for students in the various fields of engi-
neering but it is felt that students in other disciplines will welcome and benefit
from the engineering approach. Since the book has been written as a general
introduction to the quantitative aspects of the properties and processing of plas-
tics, the depth of coverage is not as great as may be found in other texts on the
physics, chemistry and stress analysis of viscoelastic materials. this has been
done deliberately because it is felt that once the material described here has
been studied and understood the reader will be in a better position to decide
if he requires the more detailed viscoelastic analysis provided by the advanced
texts.
In this book no prior knowledge of plastics is assumed. Chapter 1 provides
a brief introduction to the structure of plastics and it provides an insight to
the way in which their unique structure affects their performance. There is a
resume of the main types of plastics which are available. Chapter 2 deals with
the mechanical properties of unreinforced and reinforced plastics under the
general heading of deformation. The time dependent behaviour of the materials
is introduced and simple design procedures are illustrated. Chapter 3 continues
the discussion on properties but concentrates on fracture as caused by creep,
fatigue and impact. The concepts of fracture mechanics are also introduced for
reinforced and unreinforced plastics.
Chapter 4 describes in general terms the processing methods which can be
used for plastics and wherever possible the quantitative aspects are stressed.
In most cases a simple Newtonian model of each of the processes is devel-
oped so that the approach taken to the analysis of plastics processing is not
concealed by mathematical complexity. Chapter 5 deals with the aspects of the
flow behaviour of polymer melts which are relevant to the processing methods.
The models are developed for both Newtonian and Non-Newtonian (Power
Law) fluids so that the results can be directly compared.
Throughout the book there are worked examples to illustrate the use of the
theory and at the end of each chapter there are problems to be solved by the
reader. These are seen as an important part of the book because in solving the
problems the reader is encouraged to develop the subject material beyond the
level covered in the text. Answers are given for all the questions.

R.J. Crawford