The screw extruder was one of the first machines to be developed for the plastics processing industry and is still one of the dominant processes used today. Progress in extrusion in the last 20 years has been rapid and there is every indication that the process will continue to grow in importance in the future as we understand more about the science and technology of the process.

This review describes the changes in the industry over the last 5 years, concentrating on the screw extrusion process where the extruded product has a constant cross-section. Film and sheet production and pultrusion are not included in this review. Products and applications are reviewed in detail and major advances such as computer control, materials and speed and size issues are also covered. For general extruded products the issues are as much those of flexibility and control as those of significant new technological advances.

Topics included in this review are: Single and twin screw extruders; Die and calibrator design; Downstream equipment; Controls, monitoring and fault finding; Modelling and simulation; Materials; Products; Environmental issues.

Applications described in this review are: general profiles, pipe and tubing, waste and rainwater goods, gas and water distribution pipes, domestic water supply, corrugated pipe, foamed core and skinned pipes.

An additional indexed section containing some 500 references and abstracts from the Polymer Library provides many more examples of the applications of plastics profile extrusion. This report will be of interest to anyone who manufacturers or uses plastic profiles.