ER-WE-PA has been a supplier of extrusion machinery for some 40 years, and since 1967 has concentrated primarily on coextrusion. Dragan Djordjevic has been R & D Manager with the company for 15 years, and with over 70 papers and several patents to his name he is recognised worldwide as an expert in coextrusion and extrusion coating.

In this Review Report he reviews sheet and profile extrusion, wire and cable coating and coinjection, describing both the rheological and structural considerations and the design and selection of machinery. Problems of layer instability and the measurement of layer thickness are addressed, as well as the selection of polymers and the recyclability of coextruded scrap.

This review is supported by an extensive bibliography compiled from the Polymer Library.