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:
Mar. 25, 1980
Filed:
Oct. 05, 1978
Hans R Frankfort, Kinston, NC (US);
Benjamin H Knox, Kinston, NC (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
Poly(ethylene terephthalate) filaments of enhanced dyeability, low boil-off shrinkage (even in as-spun condition), good thermal stability over a large temperature range; and useful as texturing feed yarns and/or as hard yarns requiring no further drawing are prepared by spinning at extremely high speeds, and are characterized by a long period spacing above 300 A in their as-spun condition, and, whether in as-spun condition or after heat-treatment, by a low skin-core value as measured by a differential birefringence in relation to their stress measured at 20% extension (which correlates approximately with the spinning speed), a large crystal size, and low amorphous orientation. The continuous filament yarns may be draw-textured to provide textured yarns which also show enhanced dyeability. The staple fiber yarns also have very useful properties as compared with conventional staple yarns. A preferred process of spinning at these extremely high speeds is characterized by the use of a spinneret with capillary-dimensions that produce high shear as the polyester is extruded, and is applicable also to copolyesters, whose filaments show a similar low skin-core in relation to their stress at 20% extension, the precise values for copolymers being different from the relationship for poly(ethylene terephthalate).