| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a spinneret producing synthetic fibers with slight yarn breakage, etc., without fracturing or cracking even when a large mechanical stress or thermal stress is applied. <P>SOLUTION: The spinneret 10 has a plurality of through-holes 2 arranged in the form of rows between both main surfaces 3a and 3b of a plate 5 composed of polycrystalline ceramics 1 and is used for introducing a molten resin into the through-holes 2, extruding the resin and producing the synthetic fibers. The spinneret has ≤5×10<SP>-6</SP>/K coefficient of thermal expansion, ≥500 MPa bending strength at room temperature and ≥80% ratio of the bending strength at 500°C to that at room temperature, ≥20 W/m×K heat conductivity and has a less grain boundary phase in at least a part of the inner peripheral surface of the through-holes 2 than that of the interior. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
