Process for making hollow nylon filaments
US5439626A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1994 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Mar 14, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/3106
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
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 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 …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.