Solid‐State Extrusion

Abstract

A brief information is given on solid‐state extrusion (SSE), a method for the attaining a high‐oriented state of polymers, which is based on polymer deformation at temperatures just below the polymer melting point, or for amorphous polymers just above the glass‐transition temperature mainly by pressing through conical or slit dies. SSE is used for shape forming and structure modification of various polymer materials (homopolymers, polymer blends, filled polymer composites) and makes it possible to produce fibers, films, pipes, shapes including those of large cross section and different configurations, possessing high strength stress characteristics. In the paper, the most known SSE versions are considered: These are plunger extrusion and hydrostatic extrusion with the information on the influence of process controlling parameters in the structure and the properties of the processed material. New techniques of SSE are analyzed: These are equal‐channel angular and multiple angular extrusion, twist and planar twist extrusion, which, in contrast to the conventional ones, are based on polymer simple shear, not drawing. The data about specific features of realization of these methods are reported as well as structure evolution and physical and mechanical properties of the processed polymer materials of different structures: glassy and semicrystalline polymers, polymer mixtures, and filled composites.