| 摘要 |
550,852. Artificial filaments. DU PONT DE NEMOURS & CO., E. I. July 25, 1941, No. 9451. Convention date, July 25, . 1940. [Class 2 (ii)] Filaments, monofils, and like structures of polymerized hexamethylene adipamide are obtained by extruding the molten polymer through a circular orifice into a quenching liquid having substantially no solvent action on the polymer and maintained at a temperature of at least 35‹ C. The filaments or monofils obtained are of substantially circular crosssection. The quenching liquid may be water, or an alcohol, ether, ester, hydrocarbon, chlorinated hydrocarbon, or other non-solvent. It may be a mixture of non-solvents and it may contain wetting agents, dyes, and other additions. The quenching liquid may be used in the form of a bath or a spray. The molten polymer should be extruded into the quenching liquid without any prolonged cooling of the extruded polymer intervening. Thus it may be molten when it contacts the quenching liquid or may be set or partially set due to the preliminary cooling action of the air, but the temperature of the polymer should not be materially below its melting point when it enters the quenching liquid. The quenched filament may be cold drawn, preferably after a preliminary soaking treatment in water or after heating to a temperature of 50‹-100‹ C. Specifications 461,236, 461,237, and 501,197, are referred to.
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