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Mechanical Principles of Melt Processing.
Chemical Engineering Science, 1967, Vol. 22, p. 803. Pergamon Press Ltd., Oxford. Printed in Great Britain.
J. W. RICHARLJS: Introduction to Graphs and Nomograms. Iliffe Books, 161 pp. 42s (limp edition 27s d). THIS book sets out to explain in simple language how to construct various lcmds of graphs and nomograms in two dimensions. It considers Cartesian graphs, triangular diagrams, non-linear scales, various types of nomogram and the use of determinants and the “modulus concept” in constructing nomograms.
The book can be recommended to the chemical engineer in industry who has to make repeated simple calculations for process control or design purposes (the use of nomograms for finding the pressure-drop in pipes is a familiar example). It might well be drawn to the attention of students or others engaged on research, who may find nomograms useful for the rapid reduction of data and for other purposes. The book makes the minimum demands on mathematical knowledge. The hard-cover edition is too expensive to be attractive to the individual purchaser. P. V.
J. R. A. PEARSON:Mechanical Principles of Melt Processing. Pergamon Press, 1966, 35s. IN ALL engineering subjects practice inevitably precedes the development of useful analytical theories. This is usually because the complex nature of real problems only yields to analysis when a sufficient “feel” or understanding of the situations has been developed to enable realistic simplifications to be made which give soluble sets of equations. The need for a more fundamental understanding of the systems involved is felt when difficulties encountered in the field become increasingly intractable and further development is only possible by the use of rational analysis. Polymer processing is at this stage at the moment and the need for a deeper understanding of the mechanics of the machinery used is keenly felt. The use of larger and more expensive plant and the considerable capital outlay involved in setting up processing units has made many practitioners think seriously of analytical and experimental studies. There are many textbooks available and these may be grouped under two headings. 1. The practical, descriptive handbook.
2. The application of standard fluid mechanics to the particular cases involved in polymer processing. Neither is entirely satisfactory as the first contribute little to a general understanding and the second produce isolated answers which are difficult to relate to general mechanics theory and often conceal the difficulties peculiar to polymers. There is an urgent need therefore for a textbook which presents the fundamentals as a special case of continuum
DANCKWERTS
mechanics theory and lays emphasis on the nature of polymers and the analytical problems involved. Dr. Pearson’s book fulfils this role admirably and presents for the first time a completely rational approach to a subject previously regarded as 90 per cent empirical. The use of tensorial representation may deter some readers but it cannot be overstressed that the small effort involved will be amply rewarded. The basic equations are described and there is a particular useful discussion on the constitutive equations necessary to describe polymer properties. Simple systems are then discussed in terms of the general equations which will be of use to those familiar with less rigorous solutions but unfamiliar with general methods. The rest of the book is then concerned with the various manufacturing processes and deals with them as special cases of the basic equations. Detailed discussion of the simplifications made and the physics involved is a valuable aspect of the book and the reader is left with a clear understanding of where the equations to be solved come from; an all too rare situation in this subject. Detailed solutions are not given but the reader will be able to develop these as required. This is not a reference text of standard solutions but is the best starting point for both students and those familiar with the practical aspects of the subject that is available. It provides a sound mathematical and physical basis from which the reader’s own problems may be tackled. It may not be easy at first reading but the rewards will more than justify the effort involved. It is to be hoped that the prospect of the “theological” equation of state on page one will not dismay the reader. J. G. WILLIAMS
803
J. W. RICHARLJS: Introduction to Graphs and Nomograms. Iliffe Books, 161 pp. 42s (limp edition 27s d). THIS book sets out to explain in simple language how to construct various lcmds of graphs and nomograms in two dimensions. It considers Cartesian graphs, triangular diagrams, non-linear scales, various types of nomogram and the use of determinants and the “modulus concept” in constructing nomograms.
The book can be recommended to the chemical engineer in industry who has to make repeated simple calculations for process control or design purposes (the use of nomograms for finding the pressure-drop in pipes is a familiar example). It might well be drawn to the attention of students or others engaged on research, who may find nomograms useful for the rapid reduction of data and for other purposes. The book makes the minimum demands on mathematical knowledge. The hard-cover edition is too expensive to be attractive to the individual purchaser. P. V.
J. R. A. PEARSON:Mechanical Principles of Melt Processing. Pergamon Press, 1966, 35s. IN ALL engineering subjects practice inevitably precedes the development of useful analytical theories. This is usually because the complex nature of real problems only yields to analysis when a sufficient “feel” or understanding of the situations has been developed to enable realistic simplifications to be made which give soluble sets of equations. The need for a more fundamental understanding of the systems involved is felt when difficulties encountered in the field become increasingly intractable and further development is only possible by the use of rational analysis. Polymer processing is at this stage at the moment and the need for a deeper understanding of the mechanics of the machinery used is keenly felt. The use of larger and more expensive plant and the considerable capital outlay involved in setting up processing units has made many practitioners think seriously of analytical and experimental studies. There are many textbooks available and these may be grouped under two headings. 1. The practical, descriptive handbook.
2. The application of standard fluid mechanics to the particular cases involved in polymer processing. Neither is entirely satisfactory as the first contribute little to a general understanding and the second produce isolated answers which are difficult to relate to general mechanics theory and often conceal the difficulties peculiar to polymers. There is an urgent need therefore for a textbook which presents the fundamentals as a special case of continuum
DANCKWERTS
mechanics theory and lays emphasis on the nature of polymers and the analytical problems involved. Dr. Pearson’s book fulfils this role admirably and presents for the first time a completely rational approach to a subject previously regarded as 90 per cent empirical. The use of tensorial representation may deter some readers but it cannot be overstressed that the small effort involved will be amply rewarded. The basic equations are described and there is a particular useful discussion on the constitutive equations necessary to describe polymer properties. Simple systems are then discussed in terms of the general equations which will be of use to those familiar with less rigorous solutions but unfamiliar with general methods. The rest of the book is then concerned with the various manufacturing processes and deals with them as special cases of the basic equations. Detailed discussion of the simplifications made and the physics involved is a valuable aspect of the book and the reader is left with a clear understanding of where the equations to be solved come from; an all too rare situation in this subject. Detailed solutions are not given but the reader will be able to develop these as required. This is not a reference text of standard solutions but is the best starting point for both students and those familiar with the practical aspects of the subject that is available. It provides a sound mathematical and physical basis from which the reader’s own problems may be tackled. It may not be easy at first reading but the rewards will more than justify the effort involved. It is to be hoped that the prospect of the “theological” equation of state on page one will not dismay the reader. J. G. WILLIAMS
803