The technology of hot runners in plastic moulds is becoming more widely used, and this has been accompanied by an increase in the range of hot runner systems available. This development has meant that in manufacturing practice, the user of hot runner moulds is faced with the problem of how to make an informed comparison between the systems on offer from the mass of technical information at his disposal. The large range of hot runner systems on the market and the complex link between their design and the result obtained in practice means that many designers and users have difficulty in making the best choice. Besides economic and technical considerations, this choice must also take into account the specific properties of the plastics. An understanding of the physical processes taking place in the mould during injection forms a basis for informed mould building and optimum selection of the hot runner system, and for its subsequent operation. This is an aspect! to which this book gives special attention.

The aim of this book is to give an objective view of the topic based on personal experience. It introduces a logical division of hot runner systems, illustrates the design of nozzles, manifolds and other system components, discusses the principles of selection, building, installation and use, analyses the causes of faults and suggests ways of eliminating them, and presents examples of applications.

Subjects covered are:

* Types of Hot Runner System
* Conditions for Use of Hot Runners
* Links with Technology
* Structure of a Hot Runner
* Thermal Balance and Temperature Control
* Filling Balance
* Choosing an Hot Runner System
* Special Injection Processes using Hot Runners
* Special Hot Runner Mould Designs
* Use of Moulds with Hot Runners
* Disruptions to the Operation of Hot Runner Moulds and Typical Moulding Defects
* The Way Ahead for Hot Runner Technology