| 摘要 |
<p>The present invention provides an improved process for extruding liquid crystal polymer. The process comprises the steps of providing a fluid stream of liquid crystal polymer wherein the stream has a flow pattern comprising substantial shear flow; converting the flow of the fluid stream of liquid crystal polymer to a substantially elongational flow in the substantial absence of shear flow; and extruding the fluid stream of liquid crystal polymer to form a shaped article having the polymer molecules oriented substantially parallel to the flow direction. The resulting articles are self-reinforcing, having mechanical properties superior to conventional extruded liquid crystal polymer articles and comparable to those of articles formed from fiber-reinforced isotropic polymeric materials. In a preferred embodiment, the flow of the fluid stream of liquid crystal polymer is converted to a substantially elongational flow by passing the fluid stream of liquid crystal polymer through at least one grid having a plurality of converging passages (e.g., cone-shaped or trumpet-shaped holes).</p> |
