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:
Dec. 25, 1979
Filed:
Jun. 14, 1978
John D Gibbon, Charlotte, NC (US);
Fiber Industries, Inc., New York, NY (US);
Abstract
A low denier, high tenacity poly(ethylene terephthalate) fibrillated tape yarn particularly suited for conversion into a sewing thread which exhibits excellent sewing performance is produced by intimately mixing poly(ethylene terephthalate) polymer with from about 0.1 to 20 percent polypropylene based on the weight of poly(ethylene terephthalate), extruding the polymer mixture in the form of a tape through a slit die having a modified entry port wherein the depth of the slit is greater at both ends than at the middle, at a melt draw down of from about 26:1 to about 75:1, quenching said tape, hot drawing said tape in two stages wherein said tape is initially hot drawn to a draw ratio of from about 3.3 to about 4.2 while being subjected to a temperature of from about 80 to about 140 degree centigrade, thereafter hot drawing to a total draw ratio of about 5.0 while heated to a temperature about 160 degrees and thereafter subjecting the tape to fibrillation. A slit die with a modified entry port which allows extrusion of a low denier tape at high draw down ratios is also disclosed.