| 摘要 |
PURPOSE:To obtain easily the titled yarn useful as an ultrafilter, etc., having specific average pore diameter, good gas permeability, and liquid treating properties, by subjecting a fiber-forming isotactic PP to melt spinning at a specific hollow ratio by a nozzle to prepare hollow yarn of macaroni type, winding it at high speed. CONSTITUTION:A film-forming isotactic polypropylene is subjected to melt spinning by using a nozzle to prepare hollow yarn of macaroni type to make >=7% hollow ratio of hallow yarn, and wound at >=2,000m/min, to give the desired hollow yarn having >=50 pores with 400-700Angstrom average pore diameter based on total pore volume, and the maximum of pore volume distribution curve in the range of 400-700Angstrom average pore diameter. The winding speed of the hollow yarn is preferably 4,000-6,000m/min.
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