- Email: [email protected]
Development in injection moulding—2. Improving efficiency
209
Strength of Materials subject matter, are suitable for an undergraduate first course in solid mechanics. Chapter 4: Three Dimensional Stress and Strain, shows the application of tensor calculus to stress and strain analysis. Notational conventions, principal directions, coordinates transformation, and invariants are some of the topics included. The chapter is suitable for teaching to advanced undergraduates or first-year postgraduate students in engineering or engineering science. Chapter 5: Tensor-Matrix-Computer Methods, discusses matrix algebra and its application to stresses, strains and stress--strain relations in elasticity and plasticity. It treats, among others, equations of equilibrium and compatibility, in rectangular Cartesian coordinates as well as curvilinear orthogonal ones. The volume ends with nine useful Appendices on determinants and their expansion; Cramer's rule for solving linear simultaneous equations; matrix algebra; a Fortran program for the solution of the stress or strain eigen equation; and a programmable calculator program for principal stress (or strain). Volume 2: Applications, (ISBN 0-85312-280-6), which is referenced throughout Volume 1, is due to be published towards the end of 1982. In the Preface, Professor Alexander indicates that it contains applications of the fundamentals to "problems of interest in engineering such as bending, torsion, buckling and failure of beams, bars, shells, etc." The reviewers therefore await the publication of this companion volume with interest. S.H. TALBERT B. A V I T Z U R
Developments in Injection Moulding -- 2. Improving Efficiency, edited by A. Whelan and J.L. Craft, Applied Science, Barking, Essex, 1981. ISBN 0-85334-968-1, x + 349 pages, 25 tables, 100 illustrations, hard cover £36.00.
The editors have collated information on the injection moulding practice of thermo-plastics which extends knowledge in this field and treats the subject as a coherent package. Chapter one discusses the use of energy in injection moulding and shows where savings might be made. Useful leads are given which in practice could be followed-up with advantage. A small criticism: units used should either be Imperial or S.I. and not a random mixture. Chapter two discusses the injection moulding unit. Some of the information is well known but collectively it is very comprehensive, offering information on screw design and instrumentation of moulding parameters not readily available elsewhere. Chapter three contains the discussion of moulding-parameter instrumentation and its extension to adaptive process-control. While the technical advantages are apparent, some cost--benefit analysis justifying the technology,
210 and a case study would have greatly increased the worth of the contribution. Chapter four deals with "Designing for P r o d u c t i o n " and while much of the information in this chapter is well known, the topics have a place in this b o o k and are well covered by the author. Mention might have been made of the information on design available from the suppliers of particular polymers, which would amplify the points made. In chapter five, " H e a t Exchange Calculations", water circulating systems and alternatives to water are comprehensively covered. The economics of heat recovery systems are evaluated. Chapter six is on "Machine Control Using Microprocessors". This chapter describes the working of the microprocessor and h o w it may be connected to other devices and interfaced to give process control. Microprocessor-controlled open- and closed-loop systems are also discussed. Some commercially available microprocessor-controlled systems are reviewed, although no economic analysis justifying their use is given. No mention is made of commercially available "Black Boxes" which, with a microcomputer, could make a process-reporting system available w i t h o u t adaptive control. Chapter seven, "The Case for the Simple Machine", restates at length much of what hardly justifies inclusion in the book. A condensed text would have been adequate here. Chapter eight, "Machine Design for Specific Purposes", gives a most interesting and factual discussion on thin-wall container moulding. Processes, moulds and materials are compared and materials handling at high production-rates is discussed. Chapter nine discusses "Plant L a y o u t and Materials Handling", and is well set out and interesting and could apply to setting up a factory in other industries also. More detailed information in the handling of components from moulding machine to inspection would have been of interest. Information on the likely application of robots to materials handling and prospective cost reduction would have been a timely inclusion. A worthwhile collection of information has been made but with the rapid increase in knowledge and its application in the fields covered by the book, further editions will have to be prepared if the contents are to be maintained up to date and relevant. F.I. SIMPSON
Strength of Materials subject matter, are suitable for an undergraduate first course in solid mechanics. Chapter 4: Three Dimensional Stress and Strain, shows the application of tensor calculus to stress and strain analysis. Notational conventions, principal directions, coordinates transformation, and invariants are some of the topics included. The chapter is suitable for teaching to advanced undergraduates or first-year postgraduate students in engineering or engineering science. Chapter 5: Tensor-Matrix-Computer Methods, discusses matrix algebra and its application to stresses, strains and stress--strain relations in elasticity and plasticity. It treats, among others, equations of equilibrium and compatibility, in rectangular Cartesian coordinates as well as curvilinear orthogonal ones. The volume ends with nine useful Appendices on determinants and their expansion; Cramer's rule for solving linear simultaneous equations; matrix algebra; a Fortran program for the solution of the stress or strain eigen equation; and a programmable calculator program for principal stress (or strain). Volume 2: Applications, (ISBN 0-85312-280-6), which is referenced throughout Volume 1, is due to be published towards the end of 1982. In the Preface, Professor Alexander indicates that it contains applications of the fundamentals to "problems of interest in engineering such as bending, torsion, buckling and failure of beams, bars, shells, etc." The reviewers therefore await the publication of this companion volume with interest. S.H. TALBERT B. A V I T Z U R
Developments in Injection Moulding -- 2. Improving Efficiency, edited by A. Whelan and J.L. Craft, Applied Science, Barking, Essex, 1981. ISBN 0-85334-968-1, x + 349 pages, 25 tables, 100 illustrations, hard cover £36.00.
The editors have collated information on the injection moulding practice of thermo-plastics which extends knowledge in this field and treats the subject as a coherent package. Chapter one discusses the use of energy in injection moulding and shows where savings might be made. Useful leads are given which in practice could be followed-up with advantage. A small criticism: units used should either be Imperial or S.I. and not a random mixture. Chapter two discusses the injection moulding unit. Some of the information is well known but collectively it is very comprehensive, offering information on screw design and instrumentation of moulding parameters not readily available elsewhere. Chapter three contains the discussion of moulding-parameter instrumentation and its extension to adaptive process-control. While the technical advantages are apparent, some cost--benefit analysis justifying the technology,
210 and a case study would have greatly increased the worth of the contribution. Chapter four deals with "Designing for P r o d u c t i o n " and while much of the information in this chapter is well known, the topics have a place in this b o o k and are well covered by the author. Mention might have been made of the information on design available from the suppliers of particular polymers, which would amplify the points made. In chapter five, " H e a t Exchange Calculations", water circulating systems and alternatives to water are comprehensively covered. The economics of heat recovery systems are evaluated. Chapter six is on "Machine Control Using Microprocessors". This chapter describes the working of the microprocessor and h o w it may be connected to other devices and interfaced to give process control. Microprocessor-controlled open- and closed-loop systems are also discussed. Some commercially available microprocessor-controlled systems are reviewed, although no economic analysis justifying their use is given. No mention is made of commercially available "Black Boxes" which, with a microcomputer, could make a process-reporting system available w i t h o u t adaptive control. Chapter seven, "The Case for the Simple Machine", restates at length much of what hardly justifies inclusion in the book. A condensed text would have been adequate here. Chapter eight, "Machine Design for Specific Purposes", gives a most interesting and factual discussion on thin-wall container moulding. Processes, moulds and materials are compared and materials handling at high production-rates is discussed. Chapter nine discusses "Plant L a y o u t and Materials Handling", and is well set out and interesting and could apply to setting up a factory in other industries also. More detailed information in the handling of components from moulding machine to inspection would have been of interest. Information on the likely application of robots to materials handling and prospective cost reduction would have been a timely inclusion. A worthwhile collection of information has been made but with the rapid increase in knowledge and its application in the fields covered by the book, further editions will have to be prepared if the contents are to be maintained up to date and relevant. F.I. SIMPSON