Process for producing high-strength, ultralow denier polybenzimidazole (PBI) filaments
US4263245A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 23, 1979 |
| Grant date | Apr 21, 1981 |
| Priority date | — |
| Expiry date | Apr 23, 1999 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01D5/12
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An improved process for the production of ultralow denier, high-strength polybenzimidazole filaments is provided. A solution of the polymer is extruded vertically downward through a plurality of extrusion orifices into a gaseous atmosphere before being passed through a liquid coagulation bath. During their passage from the extrusion orifices to the exit from the coagulation bath, the filaments are drawn at an initial draw ratio of approximately 2:1 to 50:1. After being passed through the coagulaton bath, the filaments are washed, dried, and heat drawn at a heat draw ratio of approximately 1.5:1 to 10:1. The resulting filaments, having a denier per filament of approximately 0.05 to 0.50 and a tenacity of at least 4 grams per denier, are collected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.