In the field of plastics technology, the process of extrusion is
widespread and important. It is employed in the compounding and
pelletising of plastics materials, in their conversion into products
(such as profiles, pipe, hose, sheet, film or bottles) and in the
coating of wires, cables, paper, board or foil. A major reason for its
use is the screw extruder's ability to melt efficiently and pump
continuously large amounts of plastics materials. The understanding of
the melting/pumping operation of the extruder and the development of
larger and faster-running machines so as to give higher outputs have
been given great attention and the results have been widely published.
However, the whole manufacturing technology for extruded products has
also developed, particularly in recent years. This has occurred not only
by the use of modern screw extruders, but also by the incorporation of
improved process control systems, the better design of dies and
extrudate handling machinery and by the utilisation of improved plastics
materials and additives. It is the purpose of this book to present
selected topics which contribute to, or exemplify, these developments in
extrusion-based processes.