The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 01, 1997
Filed:
Jun. 07, 1995
David Arthur Price, Smyrna, DE (US);
James Preston Bennett, Hixson, TN (US);
Benjamin Hughes Knox, Wilmington, DE (US);
Dennis Raymond Schafluetzel, Hixson, TN (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
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.