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:
Apr. 21, 1981
Filed:
Apr. 23, 1979
Marshall Tan, Ridgefield Park, NJ (US);
Celanese Corporation, New York, NY (US);
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.