チタン酸カリウム繊維/ポリスチレン複合材成形における繊維の流動配向. リザーバ付きキャピラリー流動の影響
Flow Induced Fiber Orientation in the Molding of Potassium Titanate Fiber/Polystyrene CompositesI. Effect of Flow through the Die with Reservoir
竹田 啓・情野康男
Takeda, Hiraku / Seino, Yasuo
The rheological properties of composites filled with 10〜50 wt% of fibers were studied. The flow activation energy was not affected by the addition of fibers. The plots of swell ratio against shear stress were independent of melt temperature. The orientation factors of extrudates and of the samples removed from the capillary after terminating extrusion were examined at various shear rates by WAXD. A skincore structure was found in the extrudates but not in the sample removed from the capillary. The fibers in the skin were highly oriented along the flow, whereas the fibers in the core were oriented in a zig-zag manner. Goettler's theory for estimating the effect of extensional flow in a reservoir on the distribution of orientation angle could well describe the distributions obtained here. However, the orientation factors estimated from the theory are always smaller than the experimental valves. One possible reason can be ascribed to the neglect of shear effects.
Key words: FRP / Titanate fiber / Extrusion / Fiber orientation / Viscpsity orientation / Viscosity / Die swell / X-ray diffraction