Filaments, tow, and webs formed by hydraulic spinning

摘要

A method of forming substantially continuous filaments which involves the steps of (1) extending a molten thermoplastic polymer through a die having a plurality of orifices to give a plurality of substantially continuous filaments; (2) quenching the filaments by contacting them with a quenching fluid having a temperature less than that of the filaments and a zero to high imposed velocity which, if other than zero, has a component which is in a direction other than parallel with the movement of filaments; (3) entraining and drawing the filaments in a nozzle with an attenuating liquid having a linear speed of at least about 400 feet/minute; and (4) collecting the drawn filaments. The filaments have an average diameter in the range of from about 5 to about 75 micrometers and a high variability of filament diameter from filament to filament and along the length of any given filament. In addition, at least some of such filaments are present as filament bundles. Such filaments can be collected as tow or can form the basis of a nonwoven web which is characterized by minimal filament-to-filament fusion bonding. The preferred thermoplastic polymers are polyolefins, with the most preferred polyolefin being polypropylene.