摘要 |
A process for extruding polymer material, in which the material (18) is rapidly compacted and forced through an extrusion aperture (16). The rate of extrusion may be such as to cause rapid heating of the material (18) without melting of the material (18), followed immediately by cooling of the material (18) to retain to a substantial extent the molecular orientation in the material (18) as it passes through the aperture (16). The process is conveniently performed in Conform Apparatus (10, 10a) having an extended grip area for the material (18). |