E.i. Dupont De Nemours and Company

James P Bennett

Benjamin H Knox

Dennis R Schafluetzel

David A Price, Sr

David Arthur Price

A melt spinning process and the nylon hollow filaments and yarns made by such process which includes extruding molten nylon polymer having a relative viscosity (RV) of at least about 50 and a melting point (T.sub.M) of about 210.degree. C. to about 310.degree. C. from a spinneret capillary orifice with multiple orifice segments providing a total extrusion area (EA) and an extrusion void area (EVA) such that the fractional extrusion void content, defined by the ratio [EVA/EA] is about 0.6 to about 0.95, and the extent of melt attenuation, defined by the ratio [EVA/(dpf).sub.S ], is about 0.05 to about 1.5, in which (dpf).sub.S is the spun denier per filament, the (dpf).sub.S being selected such that the denier per filament at 25% elongation (dpf).sub.25 is about 0.5 to about 20 denier; withdrawing the multiple melt streams from the spinneret into a quench zone under conditions which causes substantially continuous self-coalescence of the multiple melt streams into spun filaments having at least one longitudinal void and a residual draw ratio (RDR) of less than 2.75; and stabilizing the spun hollow filaments to provide hollow filaments with a residual draw ratio (RDR) of about 1.2 to about 2.25.

Hollow nylon filaments and yarns

Hollow nylon filaments

A melt spinning process and the nylon hollow filaments and yarns made by such process which includes extruding molten nylon polymer having a relative viscosity (RV) of at least about 50 and a melting point (T.sub.M) of about 210.degree. C. to about 310.degree. C. from a spinneret capillary orifice with multiple orifice segments providing a total extrusion area (EA) and an extrusion void area (EVA) such that the fractional extrusion void content, defined by the ratio [EVA/EA] is about 0.6 to about 0.95, and the extent of melt attenuation, defined by the ratio [EVA/(dpf).sub.S ], is about 0.05 to about 1.5, in which (dpf).sub.S is the spun denier per filament, the (dpf).sub.S being selected such that the denier per filament at 25% elongation (dpf).sub.25 is about 0.5 to about 20 denier; withdrawing the multiple melt streams from the spinneret into a quench zone under conditions which causes substantially continous self-coalescence of the multiple melt streams into spun filaments having at least one longitudinal void and a residual draw ratio (RDR) of less than 2.75; and stabilizing the spun hollow filaments to provide hollow filaments with a residual draw ratio (RDR) of about 1.2 to about 2.25.

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Hixson, TN, United States of America

James P Bennett